Women and Cancer, Seventh Edition

By Omnigraphics

Consumer health information about risk factors, prevention, diagnosis, and treatment of cancers of concern to women. Includes index, glossary of related terms, and other resources.

• Language: English
• Publisher: Omnigraphics
• Release date: Mar 1, 2022
• ISBN: 9780780819931

Book preview

Preface

About This Book

Cancer is a group of diseases that can begin in different places in the body. All women are at risk of cancer, but some groups are at higher risk than others. Our genes, lifestyle, and the environment around us may raise or lower our risk of getting cancer. For women, the three most common cancers are breast, lung, and colorectal, and they will account for an estimated 50 percent of all new cancer diagnoses in women in 2020. With improved cancer screening programs and innovative treatments, women receiving a cancer diagnosis today have a better chance of overcoming their disease than ever before.

Women and Cancer Sourcebook, Seventh Edition offers updated information about gynecologic cancers and other cancers of special concern to women, including breast cancer and cancers of the female reproductive organs. It also explains cancer risks – including lifestyle factors and inherited genetic abnormalities – and methods used to diagnose and treat cancer. Suggestions for coping with the treatment side effects are provided, and a part on cancer survivorship discusses methods for maintaining the quality of life (QOL) during and after treatment. The book concludes with a glossary of cancer-related terms, a directory of resources, and facts about locating support groups.

How to Use This Book

This book is divided into parts and chapters. Parts focus on broad areas of interest. Chapters are devoted to single topics within a part.

Part 1: Understanding Cancer Risks in Women defines what cancer is and what women must know about cancer. It also gives brief insight into common gynecologic conditions that are not cancerous, cancer risks associated with factors and diseases such as smoking, human papillomavirus (HPV), hormonal medications, and cancer-causing substances in the environment.

Part 2: Breast Cancer begins with statistical data on breast cancer and offers facts about breast cancer including information about risk and protective factors. Screening and diagnostic methods, staging, and treatment options are also discussed. Facts about breast cancer and pregnancy are also included.

Part 3: Gynecologic Cancers discusses cancers of a woman’s reproductive organs. Individual chapters include information about symptoms, diagnosis, and treatment of cervical cancer, endometrial cancer, gestational trophoblastic tumors, ovarian cancer, uterine cancer, vaginal cancer, and vulvar cancer.

Part 4: Other Cancers of Special Concern to Women discusses cancers other than gynecologic cancers that have a higher prevalence among women than men or those cancer types responsible for the most cancer-related deaths among women. It provides detailed information on anal cancer, colorectal cancer, gallbladder cancer, bile duct cancer, lung cancer, pancreatic cancer, skin cancer, and thyroid cancer.

Part 5: Diagnosing and Treating Cancer covers tests and procedures involved in cancer diagnosis, as well as information about staging and general treatment options including chemotherapy, radiation therapy, biological therapy, biological therapies, stem cell transplant, and other common surgical procedures. It also highlights complementary and alternative medicine (CAM) practices in cancer care. Information on cancer clinical trials is also included.

Part 6: Coping with the Short- and Long-Term Effects of Cancer and Cancer Treatments offers practical suggestions for dealing with common adverse effects of various cancer treatments or symptomatic consequences related to the growth of the cancer itself. These side effects include nausea, vomiting, pain, fatigue, gastrointestinal (GI) problems, lymphedema, anemia, and hair loss. It discusses many side effects of chemotherapy and radiation and how to cope with it. The part concludes with a brief overview of the cognitive-related effects of cancer treatment.

Part 7: Women’s Issues in Cancer Survivorship provides supportive information for women who have received a cancer diagnosis. It discusses maintaining the quality of daily life through proper nutrition, exercise, and attention to mental-health issues. It also discusses questions about sexual intimacy, fertility, and pregnancy among women who have been treated for gynecologic cancers, and it includes facts about the need for ongoing medical care for long-term well-being.

Part 8: Additional Help and Information offers a glossary of cancer-related terms, a directory of information resources, and suggestions for finding support groups.

Bibliographic Note

This volume contains documents and excerpts from publications issued by the following U.S. government agencies: Centers for Disease Control and Prevention (CDC); National Cancer Institute (NCI); Office on Women’s Health (OWH); Smokefree Women; and Surveillance, Epidemiology, and End Results (SEER) Program.

It also contains original material produced by Omnigraphics and reviewed by medical consultants.

About the Health Reference Series

The Health Reference Series is designed to provide basic medical information for patients, families, caregivers, and the general public. Each volume provides comprehensive coverage on a particular topic. This is especially important for people who may be dealing with a newly diagnosed disease or a chronic disorder in themselves or in a family member. People looking for preventive guidance, information about disease warning signs, medical statistics, and risk factors for health problems will also find answers to their questions in the Health Reference Series. The Series, however, is not intended to serve as a tool for diagnosing illness, in prescribing treatments, or as a substitute for the physician–patient relationship. All people concerned about medical symptoms or the possibility of disease are encouraged to seek professional care from an appropriate health-care provider.

A Note about Spelling and Style

Health Reference Series editors use Stedman’s Medical Dictionary as an authority for questions related to the spelling of medical terms and The Chicago Manual of Style for questions related to grammatical structures, punctuation, and other editorial concerns. Consistent adherence is not always possible, however, because the individual volumes within the Series include many documents from a wide variety of different producers, and the editor’s primary goal is to present material from each source as accurately as is possible. This sometimes means that information in different chapters or sections may follow other guidelines and alternate spelling authorities. For example, occasionally a copyright holder may require that eponymous terms be shown in possessive forms (Crohn’s disease vs. Crohn disease) or that British spelling norms be retained (leukaemia vs. leukemia).

Medical Review

Omnigraphics contracts with a team of qualified, senior medical professionals who serve as medical consultants for the Health Reference Series. As necessary, medical consultants review reprinted and originally written material for currency and accuracy. Citations including the phrase Reviewed (month, year) indicate material reviewed by this team. Medical consultation services are provided to the Health Reference Series editors by:

Dr. Vijayalakshmi, MBBS, DGO, MD

Dr. Senthil Selvan, MBBS, DCH, MD

Dr. K. Sivanandham, MBBS, DCH, MS (Research), PhD

Health Reference Series Update Policy

The inaugural book in the Health Reference Series was the first edition of Cancer Sourcebook published in 1989. Since then, the Series has been enthusiastically received by librarians and in the medical community. In order to maintain the standard of providing high-quality health information for the layperson the editorial staff at Omnigraphics felt it was necessary to implement a policy of updating volumes when warranted.

Medical researchers have been making tremendous strides, and it is the purpose of the Health Reference Series to stay current with the most recent advances. Each decision to update a volume is made on an individual basis. Some of the considerations include how much new information is available and the feedback we receive from people who use the books. If there is a topic you would like to see added to the update list, or an area of medical concern you feel has not been adequately addressed, please write to:

Managing Editor

Health Reference Series

Omnigraphics

615 Griswold St., Ste. 520

Detroit, MI 48226

Part 1 | Understanding Cancer Risks in Women

Chapter 1 | What You Need to Know about Cancer

Chapter Contents

Section 1.1—What Is Cancer?

Section 1.2—Most Common Types of Cancer in Women

Section 1.3—Cancer Risk Factors

Section 1.1 | What Is Cancer?

This section includes text excerpted from What Is Cancer? National Cancer Institute (NCI), May 5, 2021.

Cancer is a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body.

Cancer can start almost anywhere in the human body, which is made up of trillions of cells. Normally, human cells grow and multiply (through a process called cell division) to form new cells as the body needs them. When cells grow old or become damaged, they die, and new cells take their place.

Sometimes this orderly process breaks down, and abnormal or damaged cells grow and multiply when they should not. These cells may form tumors, which are lumps of tissue. Tumors can be cancerous or not cancerous (benign).

Cancerous tumors spread into, or invade nearby tissues and can travel to distant places in the body to form new tumors (a process called metastasis). Cancerous tumors may also be called malignant tumors. Many cancers form solid tumors, but cancers of the blood, such as leukemias, generally do not.

Benign tumors do not spread into, or invade nearby tissues. When removed, benign tumors usually do not grow back, whereas cancerous tumors sometimes do. Benign tumors can sometimes be quite large, however. Some can cause serious symptoms or be life-threatening, such as benign tumors in the brain.

Differences between Cancer Cells and Normal Cells

Cancer cells differ from normal cells in many ways. For instance, cancer cells:

Grow in the absence of signals telling them to grow. Normal cells only grow when they receive such signals.

Ignore signals that normally tell cells to stop dividing or to die (a process known as programmed cell death, or apoptosis).

Invade into nearby areas and spread to other areas of the body. Normal cells stop growing when they encounter other cells, and most normal cells do not move around the body.

Tell blood vessels to grow toward tumors. These blood vessels supply tumors with oxygen and nutrients and remove waste products from tumors.

Hide from the immune system. The immune system normally eliminates damaged or abnormal cells.

Trick the immune system into helping cancer cells stay alive and grow. For instance, some cancer cells convince immune cells to protect the tumor instead of attacking it.

Accumulate multiple changes in their chromosomes, such as duplications and deletions of chromosome parts. Some cancer cells have double the normal number of chromosomes.

Rely on different kinds of nutrients than normal cells. In addition, some cancer cells make energy from nutrients in a different way than most normal cells. This lets cancer cells grow more quickly.

Many times, cancer cells rely so heavily on these abnormal behaviors that they cannot survive without them. Researchers have taken advantage of this fact, developing therapies that target the abnormal features of cancer cells. For example, some cancer therapies prevent blood vessels from growing toward tumors, essentially starving the tumor of needed nutrients.

How Does Cancer Develop?

Cancer is a genetic disease – that is, it is caused by changes to genes that control the way our cells function, especially how they grow and divide.

Genetic changes that cause cancer can happen because:

Of errors that occur as cells divide

Of damage to deoxyribonucleic acid (DNA) caused by harmful substances in the environment, such as the chemicals in tobacco smoke and ultraviolet (UV) rays from the sun

They were inherited from our parents

The body normally eliminates cells with damaged DNA before they turn cancerous. But, the body’s ability to do so goes down as we age. This is part of the reason why there is a higher risk of cancer later in life.

Each person’s cancer has a unique combination of genetic changes. As the cancer continues to grow, additional changes will occur. Even within the same tumor, different cells may have different genetic changes.

Types of Genes That Cause Cancer

The genetic changes that contribute to cancer tend to affect three main types of genes – proto-oncogenes, tumor suppressor genes, and DNA repair genes. These changes are sometimes called drivers of cancer.

Proto-oncogenes are involved in normal cell growth and division. However, when these genes are altered in certain ways or are more active than normal, they may become cancer-causing genes (or oncogenes), allowing cells to grow and survive when they should not.

Tumor suppressor genes are also involved in controlling cell growth and division. Cells with certain alterations in tumor suppressor genes may divide in an uncontrolled manner.

DNA repair genes are involved in fixing damaged DNA. Cells with mutations in these genes tend to develop additional mutations in other genes and changes in their chromosomes, such as duplications and deletions of chromosome parts. Together, these mutations may cause the cells to become cancerous.

As scientists have learned more about the molecular changes that lead to cancer, they have found that certain mutations commonly occur in many types of cancer. Now there are many cancer treatments available that target gene mutations found in cancer. A few of these treatments can be used by anyone with a cancer that has the targeted mutation, no matter where the cancer started growing.

When Cancer Spreads

A cancer that has spread from the place where it first formed to another place in the body is called metastatic cancer. The process by which cancer cells spread to other parts of the body is called metastasis.

Metastatic cancer has the same name and the same type of cancer cells as the original, or primary, cancer. For example, breast cancer that forms a metastatic tumor in the lung is metastatic breast cancer, not lung cancer.

Under a microscope, metastatic cancer cells generally look the same as cells of the original cancer. Moreover, metastatic cancer cells and cells of the original cancer usually have some molecular features in common, such as the presence of specific chromosome changes.

In some cases, treatment may help prolong the lives of people with metastatic cancer. In other cases, the primary goal of treatment for metastatic cancer is to control the growth of the cancer or to relieve symptoms it is causing. Metastatic tumors can cause severe damage to how the body functions, and most people who die of cancer die of metastatic disease.

Tissue Changes That Are Not Cancer

Not every change in the body’s tissues is cancer. Some tissue changes may develop into cancer if they are not treated, however. Here are some examples of tissue changes that are not cancer but, in some cases, are monitored because they could become cancer:

Hyperplasia occurs when cells within a tissue multiply faster than normal and extra cells build up. However, the cells and the way the tissue is organized still look normal under a microscope. Hyperplasia can be caused by several factors or conditions, including chronic irritation.

Dysplasia is a more advanced condition than hyperplasia. In dysplasia, there is also a buildup of extra cells. But the cells look abnormal and there are changes in how the tissue is organized. In general, the more abnormal the cells and tissue look, the greater the chance that cancer will form. Some types of dysplasia may need to be monitored or treated, but others do not. An example of dysplasia is an abnormal mole (called a dysplastic nevus) that forms on the skin. A dysplastic nevus can turn into melanoma, although most do not.

Carcinoma in situ is an even more advanced condition. Although it is sometimes called stage 0 cancer, it is not cancer because the abnormal cells do not invade nearby tissue the way that cancer cells do. But because some carcinomas in situ may become cancer, they are usually treated.

Types of Cancer

There are more than 100 types of cancer. Types of cancer are usually named for the organs or tissues where the cancers form. For example, lung cancer starts in the lung, and brain cancer starts in the brain. Cancers also may be described by the type of cell that formed them, such as an epithelial cell or a squamous cell.

Here are some categories of cancers that begin in specific types of cells:

Carcinoma

Carcinomas are the most common type of cancer. They are formed by epithelial cells, which are the cells that cover the inside and outside surfaces of the body. There are many types of epithelial cells, which often have a column-like shape when viewed under a microscope.

Carcinomas that begin in different epithelial cell types have specific names:

Adenocarcinoma is a cancer that forms in epithelial cells that produce fluids or mucus. Tissues with this type of epithelial cell are sometimes called glandular tissues. Most cancers of the breast, colon, and prostate are adenocarcinomas.

Basal cell carcinoma is a cancer that begins in the lower or basal (base) layer of the epidermis, which is a person’s outer layer of skin.

Squamous cell carcinoma is a cancer that forms in squamous cells, which are epithelial cells that lie just beneath the outer surface of the skin. Squamous cells also line many other organs, including the stomach, intestines, lungs, bladder, and kidneys. Squamous cells look flat, like fish scales, when viewed under a microscope. Squamous cell carcinomas are sometimes called epidermoid carcinomas.

Transitional cell carcinoma is a cancer that forms in a type of epithelial tissue called transitional epithelium, or urothelium. This tissue, which is made up of many layers of epithelial cells that can get bigger and smaller, is found in the linings of the bladder, ureters, and part of the kidneys (renal pelvis), and a few other organs. Some cancers of the bladder, ureters, and kidneys are transitional cell carcinomas.

Sarcoma

Sarcomas are cancers that form in bone and soft tissues, including muscle, fat, blood vessels, lymph vessels, and fibrous tissue (such as tendons and ligaments).

Osteosarcoma is the most common cancer of bone. The most common types of soft tissue sarcoma are leiomyosarcoma, Kaposi sarcoma, malignant fibrous histiocytoma, liposarcoma, and dermatofibrosarcoma protuberans.

Leukemia

Cancers that begin in the blood-forming tissue of the bone marrow are called leukemias. These cancers do not form solid tumors. Instead, large numbers of abnormal white blood cells (WBCs) (leukemia cells and leukemic blast cells) build up in the blood and bone marrow, crowding out normal blood cells. The low level of normal blood cells can make it harder for the body to get oxygen to its tissues, control bleeding, or fight infections.

There are four common types of leukemia, which are grouped based on how quickly the disease gets worse (acute or chronic) and on the type of blood cell the cancer starts in (lymphoblastic or myeloid). Acute forms of leukemia grow quickly and chronic forms grow more slowly.

Lymphoma

Lymphoma is cancer that begins in lymphocytes (T cells or B cells). These are disease-fighting WBCs that are part of the immune system. In lymphoma, abnormal lymphocytes build up in lymph nodes and lymph vessels, as well as in other organs of the body.

There are two main types of lymphoma:

Hodgkin lymphoma – People with this disease have abnormal lymphocytes that are called Reed-Sternberg cells. These cells usually form from B cells.

Non-Hodgkin lymphoma (NHL) – This is a large group of cancers that start in lymphocytes. The cancers can grow quickly or slowly and can form from B cells or T cells.

Multiple Myeloma

Multiple myeloma is cancer that begins in plasma cells, another type of immune cell. The abnormal plasma cells, called myeloma cells, build up in the bone marrow and form tumors in bones all through the body. Multiple myeloma is also called plasma cell myeloma and Kahler disease.

Melanoma

Melanoma is cancer that begins in cells that become melanocytes, which are specialized cells that make melanin (the pigment that gives skin its color). Most melanomas form on the skin, but melanomas can also form in other pigmented tissues, such as the eye.

Brain and Spinal Cord Tumors

There are different types of brain and spinal cord tumors. These tumors are named based on the type of cell in which they formed and where the tumor first formed in the central nervous system. For example, an astrocytic tumor begins in star-shaped brain cells called astrocytes, which help keep nerve cells healthy. Brain tumors can be benign (not cancer) or malignant (cancer).

Other Types of Tumors

Germ Cell Tumors

Germ cell tumors are a type of tumor that begins in the cells that give rise to sperm or eggs. These tumors can occur almost anywhere in the body and can be either benign or malignant.

Neuroendocrine Tumors

Neuroendocrine tumors form from cells that release hormones into the blood in response to a signal from the nervous system. These tumors, which may make higher-than-normal amounts of hormones, can cause many different symptoms. Neuroendocrine tumors may be benign or malignant.

Carcinoid Tumors

Carcinoid tumors are a type of neuroendocrine tumor. They are slow-growing tumors that are usually found in the gastrointestinal system (most often in the rectum and small intestine). Carcinoid tumors may spread to the liver or other sites in the body, and they may secrete substances such as serotonin or prostaglandins, causing carcinoid syndrome.

Section 1.2 | Most Common Types of Cancer in Women

Most Common Types of Cancer in Women, © 2022 Omnigraphics. Reviewed January 2022.

One out of four people in the United States die from cancer every year and is notably the second major cause of death in the country. According to the 2018 statistics provided by the Centers for Disease Control and Prevention (CDC), there was a total of new 1,708,921 cancer cases in the United States of which 845,972 of these cases had affected women.

While talking about cancer can be depressing, knowing and having information about the disease is always helpful. People can focus on living a healthy life if they understand the most prevalent types

Figure 1.1. Cancer Types

of cancer, identifying cancer at its early stages, and the risk factors and lifestyle decisions that may contribute to cancer development.

Cancer is frequently connected to family medical history, lifestyle decisions, or environmental factors. While one cannot control their family history or surroundings, they can definitely have a healthy lifestyle including a balanced diet, frequent physical activity, weight management, and avoiding smoking.

The types of cancer that mostly affect women are listed below.

Breast Cancer

This most prevalent cancer among women involves cells in the breast to multiply in the region around the breast and extend up to the lymph nodes beneath the arms. In 2020, the United States alone recorded nearly 276,480 new cases of invasive breast cancer in women.

Breast cancer among women is more likely due to one or more of the following risk factors:

Being obese or overweight

Sedentary lifestyle

Inability to conceive a child

Over usage of oral contraceptives

Hormone replacement treatment (HRT) after menopause

Prolonged usage of deodorants and roll-ons in the underarm.

Although there is no standard method to avoid breast cancer, there are steps one can take to reduce their risk. A balanced diet, regular exercise and physical activity, and breastfeeding your infant are a few steps a woman can follow to reduce any risk of developing breast cancer.

Cervical Cancer

According to American Cancer Society (ACS), around 14,000 new cases of cervical cancer were diagnosed in the United States in 2020.

Cervical cancer can occur most likely if a woman has one or more of the following risk factors:

HPV (human papillomavirus) infection accounts for 90 percent or more of all cervical cancer cases

Pap smear that is abnormal

Being affected by human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)

Being on oral birth control for a prolonged period

Having numerous sexual partners

Cervical cancer has no early warning signs or symptoms. However, as the condition progresses, abnormal vaginal bleeding or discharge may occur (likely after sex).

Lung Cancer

The lungs and the trachea, which are divided into the bronchia, bronchioles, and alveoli, are affected by lung cancer. The ACS estimated nearly 116,660 new lung cancer cases and 62,470 deaths among women in 2021.

Smoking or secondhand smoke is the most significant risk factor for lung cancer. Quitting smoking, and avoiding secondhand smoke are the finest lifestyle choices one can make to avoid lung cancer.

To reach your state’s helpline, dial 800-QUIT-NOW (800-784-8669) and chat with a counselor about quitting smoking.

Ovarian Cancer

Ovarian cancer, which is the abnormal development of cells in the ovaries and fallopian tubes, is another prevalent disease in women. Ovarian cancer develops when cells in the ovaries and fallopian tubes grow out of control and become tumors.

In the year 2020, the ACS reported 21,750 new cases of ovarian cancer. A few risk factors that can lead to ovarian cancer are:

Obesity

Diabetes

Prolonged usage of talcum powder in the pubic area

Hormone replacement treatment

Smoking

Polycystic ovarian syndrome (PCOS)

Lynch syndrome

A family history of breast, uterine, cervical, intestinal, or ovarian cancer

Skin Cancer

Skin cancer is the abnormal development of skin cells that is frequently caused by exposure to ultraviolet (UV) radiation. Women are more likely than men to develop skin cancer globally. In the U.S. alone, 43,850 women were affected by skin cancer in 2018. The following are the most prevalent types of skin cancer:

Basal cell carcinoma

Squamous cell carcinoma

Melanoma (malignant melanoma)

Uterine Cancer

Endometrial carcinoma is a type of cancer that affects the uterine lining and is the most frequent type of gynecologic cancer. The uterus, often known as the womb, is a hollow, pear-shaped organ where the menstrual cycles and fetal development take place.

Women above the age of 55 are more prone to get uterine cancer. According to the ACS, 65,000 new cases of uterine cancer were detected in 2020. While there is no method to avoid uterine cancer, using oral contraceptives, undergoing progesterone and estrogen hormone replacement treatment, and maintaining a healthy weight may reduce the risk of developing this cancer.

The following are some of the risk factors that can increase the chances of uterine cancer:

Obesity

Usage of tamoxifen drug to treat breast cancer

Diabetes

History of cancer in the family

Lynch syndrome

References

Cancer Data and Statistics, Centers for Disease Control and Prevention (CDC), June 8, 2021.

Hook B, Debra-Lynn. The Top 5 Cancers Affecting Women, Everyday Health, October 9, 2017.

Key Statistics for Lung Cancer, American Cancer Society (ACS), January 12, 2021.

Most Common Cancers in Women and How to Detect Them Early, The University of Kansas Cancer Center, August 21, 2020.

U.S. Cancer Statistics: Highlights from 2018 Incidence, Centers for Disease Control and Prevention (CDC), June 8, 2021.

Section 1.3 | Cancer Risk Factors

This section includes text excerpted from Cancer Prevention Overview (PDQ®) – Patient Version, National Cancer Institute (NCI), October 8, 2021.

Scientists study risk factors and protective factors to find ways to prevent new cancers from starting. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Risk factors that a person can control are called modifiable risk factors.

Many other factors in our environment, diet, and lifestyle may cause or prevent cancer. This section reviews only the major cancer risk factors and protective factors that can be controlled or changed to reduce the risk of cancer. Risk factors that are not described in the section include certain sexual behaviors, the use of estrogen, and being exposed to certain substances at work or to certain chemicals.

Factors That Are Known to Increase the Risk of Cancer

Cigarette Smoking and Tobacco Use

Tobacco use is strongly linked to an increased risk for many kinds of cancer.

Not smoking or quitting smoking lowers the risk of getting cancer and dying from cancer. Scientists believe that cigarette smoking causes about 30 percent of all cancer deaths in the United States.

Infections

Certain viruses and bacteria are able to cause cancer. Examples of cancer-causing viruses and bacteria include:

Human papillomavirus (HPV) increases the risk for cancers of the cervix, penis, vagina, anus, and oropharynx.

Hepatitis B and hepatitis C viruses increase the risk for liver cancer.

Epstein-Barr virus increases the risk for Burkitt lymphoma.

Helicobacter pylori increases the risk for gastric cancer.

Two vaccines to prevent infection by cancer-causing agents have already been developed and approved by the U.S. Food and Drug Administration (FDA). One is a vaccine to prevent infection with hepatitis B virus. The other protects against infection with strains of HPV that cause cervical cancer. Scientists continue to work on vaccines against infections that cause cancer.

Radiation

Being exposed to radiation is a known cause of cancer. There are two main types of radiation linked with an increased risk for cancer:

Ultraviolet radiation from sunlight: This is the main cause of nonmelanoma skin cancers.

Ionizing radiation including:

Medical radiation from tests to diagnose cancer such as x-rays, CT scans, fluoroscopy, and nuclear medicine scans.

Radon gas in our homes.

Scientists believe that ionizing radiation causes leukemia, thyroid cancer, and breast cancer in women. Ionizing radiation may also be linked to myeloma and cancers of the lung, stomach, colon, esophagus, bladder, and ovary. Being exposed to radiation from diagnostic x-rays increases the risk of cancer in patients and x-ray technicians. Diagnostic radiation in children and adolescents has been linked with a higher risk of cancers at a young age.

The growing use of CT scans over the last 20 years has increased exposure to ionizing radiation. The risk of cancer also increases with the number of CT scans a patient has and the radiation dose used each time.

Immunosuppressive Medicines after Organ Transplant

Immunosuppressive medicines are used after an organ has been transplanted from one person to another. These medicines stop an organ that has been transplanted from being rejected. These medicines decrease the body’s immune response to help keep the organ from being rejected. Immunosuppressive medicines are linked to an increased risk of cancer because they lower the body’s ability to keep cancer from forming. The risk of cancer, especially cancer caused by a virus, is higher in the first 6 months after organ transplant, but the risk lasts for many years.

Factors That May Affect the Risk of Cancer

Diet

The foods that you eat on a regular basis make up your diet. Diet is being studied as a risk factor for cancer. It is hard to study the effects of diet on cancer because a person’s diet includes foods that may protect against cancer and foods that may increase the risk of cancer.

It is also hard for people who take part in the studies to keep track of what they eat over a long period of time. This may explain why studies have different results about how diet affects the risk of cancer.

Some studies have shown that a diet high in fat, proteins, calories, and red meat increases the risk of colorectal cancer, but other studies have not shown this.

It is not known if a diet low in fat and high in fiber, fruits, and vegetables lowers the risk of colorectal cancer.

Alcohol

Studies have shown that drinking alcohol is linked to an increased risk of the following types of cancers:

Oral cancer

Esophageal cancer

Breast cancer

Colorectal cancer (in men)

Drinking alcohol may also increase the risk of liver cancer and female colorectal cancer.

Physical Activity

Studies show that people who are physically active have a lower risk of certain cancers than those who are not. It is not known if physical activity itself is the reason for this.

Some studies show that physical activity protects against postmenopausal breast cancer and endometrial cancer.

Obesity

Studies show that obesity is linked to a higher risk of the following types of cancer:

Postmenopausal breast cancer

Colorectal cancer

Endometrial cancer

Esophageal cancer

Kidney cancer

Pancreatic cancer

Some studies show that obesity is also a risk factor for cancer of the gallbladder and liver cancer.

It is not known if losing weight lowers the risk of cancers that have been linked to obesity.

Diabetes

Some studies show that having diabetes may slightly increase the risk of having the following types of cancer:

Bladder cancer

Breast cancer in women

Colorectal cancer

Endometrial cancer

Liver cancer

Lung cancer

Oral cancer

Oropharyngeal cancer

Ovarian cancer

Pancreatic cancer

Diabetes and cancer share some of the same risk factors. These risk factors include the following:

Being older

Having obesity

Smoking

Not eating a healthy diet

Not exercising

Because diabetes and cancer share these risk factors, it is hard to know whether the risk of cancer is increased more by diabetes or by these risk factors.

Studies are being done to see how medicine that is used to treat diabetes affects cancer risk.

Environmental Risk Factors

Being exposed to chemicals and other substances in the environment has been linked to some cancers:

Links between air pollution and cancer risk have been found. These include links between lung cancer and secondhand tobacco smoke, outdoor air pollution, and asbestos.

Drinking water that contains a large amount of arsenic has been linked to skin, bladder, and lung cancers.

Studies have been done to see if pesticides and other pollutants increase the risk of cancer. The results of those studies have been unclear because other factors can change the results of the studies.

Chapter 2 | Common Gynecologic Conditions That Are Not Indicative of Cancer

Fibroids are muscular tumors that grow in the wall of the uterus (womb). Fibroids are almost always benign (not cancerous). Not all women with fibroids have symptoms. Women who do have symptoms often find fibroids hard to live with. Some have pain and heavy menstrual bleeding. Treatment for uterine fibroids depends on your symptoms.

What Are Uterine Fibroids?

Fibroids are muscular tumors that grow in the wall of the uterus (womb). Another medical term for fibroids is leiomyoma or just myoma. Fibroids are almost always benign (not cancerous). Fibroids can grow as a single tumor, or there can be many of them in the uterus. They can be as small as an apple seed or as big as a grapefruit. In unusual cases they can become very large.

Figure 2.1. Uterine Fibroids (Source: About Uterine Fibroids, Eunice Kennedy

Shriver National Institute of Child Health and Human Development (NICHD).)

Why Should Women Know about Fibroids?

About 20 percent to 80 percent of women develop fibroids by the time they reach age 50. Fibroids are most common in women in their 40s and early 50s. Not all women with fibroids have symptoms. Women who do have symptoms often find fibroids hard to live with. Some have pain and heavy menstrual bleeding. Fibroids also can put pressure on the bladder, causing frequent urination, or the rectum, causing rectal pressure. Should the fibroids get very large, they can cause the abdomen (stomach area) to enlarge, making a woman look pregnant.

Who Gets Fibroids

There are factors that can increase a woman’s risk of developing fibroids.

Age. Fibroids become more common as women age, especially during the 30s and 40s through menopause. After menopause, fibroids usually shrink.

Family history. Having a family member with fibroids increases your risk. If a woman’s mother had fibroids, her risk of having them is about three times higher than average.

Ethnic origin. African-American women are more likely to develop fibroids than white women.

Obesity. Women who are overweight are at higher risk for fibroids. For very heavy women, the risk is two to three times greater than average.

Eating habits. Eating a lot of red meat (e.g., beef) and ham is linked with a higher risk of fibroids. Eating plenty of green vegetables seems to protect women from developing fibroids.

Where Can Fibroids Grow?

Most fibroids grow in the wall of the uterus. Doctors put them into three groups based on where they grow:

Submucosal fibroids grow into the uterine cavity.

Intramural fibroids grow within the wall of the uterus.

Subserosal fibroids grow on the outside of the uterus.

Some fibroids grow on stalks that grow out from the surface of the uterus or into the cavity of the uterus. They might look like mushrooms. These are called pedunculated fibroids.

What Are Symptoms of Fibroids?

Most fibroids do not cause any symptoms, but some women with fibroids can have:

Heavy bleeding (which can be heavy enough to cause anemia) or painful periods

Feeling of fullness in the pelvic area (lower stomach area)

Enlargement of the lower abdomen

Frequent urination

Pain during sex

Lower back pain

Complications during pregnancy and labor, including a six-time greater risk of cesarean section

Reproductive problems, such as infertility, which is very rare

What Causes Fibroids

No one knows for sure what causes fibroids. Researchers think that more than one factor could play a role. These factors could be:

Hormonal (affected by estrogen and progesterone levels)

Genetic (runs in families)

Because no one knows for sure what causes fibroids, we also do not know what causes them to grow or shrink. We do know that they are under hormonal control – both estrogen and progesterone. They grow rapidly during pregnancy, when hormone levels are high. They shrink when antihormone medication is used. They also stop growing or shrink once a woman reaches menopause.

Can Fibroids Turn into Cancer?

Fibroids are almost always benign (not cancerous). Rarely (less than one in 1,000) a cancerous fibroid will occur. This is called leiomyosarcoma. Doctors think that these cancers do not arise from an already-existing fibroid. Having fibroids does not increase the risk of developing a cancerous fibroid. Having fibroids also does not increase a woman’s chances of getting other forms of cancer in the uterus.

What Are Ovarian Cysts?

A cyst is a fluid-filled sac. It can form in many places in the body. Ovarian cysts form in or on the ovaries.

What Are the Different Types of Ovarian Cysts?

The most common types of ovarian cysts (called functional cysts) form during the menstrual cycle. They are usually benign (not cancerous).

The two most common types of cysts are:

Follicle cysts. In a normal menstrual cycle, an ovary releases an egg each month. The egg grows inside a tiny sac called a follicle. When the egg matures, the follicle breaks open to release the egg. follicle cysts form when the follicle does not break open to release the egg. This causes the follicle to continue growing into a cyst. follicle cysts often have no symptoms and go away in one to three months.

Corpus luteum cysts. Once the follicle breaks open and releases the egg, the empty follicle sac shrinks into a mass of cells called corpus luteum. The Corpus luteum makes hormones to prepare for the next egg for the next menstrual cycle. Corpus luteum cysts form if the sac does not shrink. Instead, the sac reseals itself after the egg is released, and then fluid builds up inside. Most corpus luteum cysts go away after a few weeks. But, they can grow to almost four inches wide. They also may bleed or twist the ovary and cause pain. Some medicines used to cause ovulation can raise the risk of getting these cysts.

Other types of benign ovarian cysts are less common:

Endometriomas are caused by endometriosis. Endometriosis happens when the lining of the uterus (womb) grows outside of the uterus.

Dermoid come from cells present from birth and do not usually cause symptoms

Cystadenomas are filled with watery fluid and can sometimes grow large

In some women, the ovaries make many small cysts. This is called polycystic ovary syndrome (PCOS). PCOS can cause problems with the ovaries and with getting pregnant.

Malignant (cancerous) cysts are rare. They are more common in older women. Cancerous cysts are ovarian cancer. For this reason, ovarian cysts should be checked by your doctor. Most ovarian cysts are not cancerous.

Can Ovarian Cysts Lead to Cancer?

Yes, some ovarian cysts can become cancerous. But most ovarian cysts are not cancerous.

The risk for ovarian cancer increases as you get older. Women who are past menopause with ovarian cysts have a higher risk for ovarian cancer. Talk to your doctor about your risk for ovarian cancer. Screening for ovarian cancer is not recommended for most women. This is because testing can lead to false positives. A false positive is a test result that says a woman has ovarian cancer when she does not.

What Is Endometriosis?

Endometriosis, sometimes called endo, is a common health problem in women. It gets its name from the word endometrium, the tissue that normally lines the uterus or womb. Endometriosis happens when tissue similar to the lining of the uterus grows outside of your uterus and on other areas in your body where it does not belong.

Most often, endometriosis is found on the:

Ovaries

Fallopian tubes

Tissues that hold the uterus in place

The outer surface of the uterus

Other sites for growths can include the vagina, cervix, vulva, bowel, bladder, or rectum. Rarely, endometriosis appears in other parts of the body, such as the lungs, brain, and skin.

What Are the Symptoms of Endometriosis?

Symptoms of endometriosis can include:

Pain. This is the most common symptom. Women with endometriosis may have many different kinds of pain. These include:

Very painful menstrual cramps. The pain may get worse over time.

Chronic (long-term) pain in the lower back and pelvis

Pain during or after sex. This is usually described as a deep pain and is different from pain felt at the entrance to the vagina when penetration begins.

Intestinal pain

Painful bowel movements or pain when urinating during menstrual periods. In rare cases, you may also find blood in your stool or urine.

Bleeding or spotting between menstrual periods. This can be caused by something other than endometriosis. If it happens often, you should see your doctor.

Infertility, or not being able to get pregnant.

Stomach (digestive) problems. These include diarrhea, constipation, bloating, or nausea, especially during menstrual periods.

Why Does Endometriosis Cause Pain and Health Problems?

Endometriosis growths are benign (not cancerous). But they can still cause problems.

Endometriosis happens when tissue similar to the lining on the inside of your uterus or womb grows outside of your uterus or womb where it does not belong. Endometriosis growths may swell and bleed in the same way the lining inside of your uterus does every month – during your menstrual period. This can cause swelling and pain because the tissue grows and bleeds in an area where it cannot easily get out of your body.

The growths may also continue to expand and cause problems, such as:

Blocking your fallopian tubes when growths cover or grow into your ovaries. Trapped blood in the ovaries can form cysts.

Inflammation (swelling)

Forming scar tissue and adhesions (a type of tissue that can bind your organs together). This scar tissue may cause pelvic pain and make it hard for you to get pregnant.

Problems in your intestines and bladder

What Causes Endometriosis

No one knows for sure what causes this disease. Researchers are studying possible causes:

Problems with menstrual period flow. Retrograde menstrual flow is the most likely cause of endometriosis. Some of the tissue shed during the period flows through the fallopian tube into other areas of the body, such as the pelvis.

Genetic factors. Because endometriosis runs in families, it may be inherited in the genes.

Immune system problems. A faulty immune system may fail to find and destroy endometrial tissue growing outside of the uterus. Immune system disorders and certain cancers are more common in women with endometriosis.

Hormones. The hormone estrogen appears to promote endometriosis. Research is looking at whether endometriosis is a problem with the body’s hormone system.

Surgery. During a surgery to the abdominal area, such as a Cesarean (C-section) or hysterectomy, endometrial tissue could be picked up and moved by mistake. For instance, endometrial tissue has been found in abdominal scars.

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This chapter contains text excerpted from the following sources: Text in this chapter begins with excerpts from Uterine Fibroids, Office on Women’s Health (OWH), U.S. Department of Health and Human Services (HHS), April 1, 2019; Text beginning with the heading What Are Ovarian Cysts? is excerpted from Ovarian Cysts, Office on Women’s Health (OWH), U.S. Department of Health and Human Services (HHS), April 1, 2019; Text beginning with the heading What Is Endometriosis? is excerpted from Endometriosis, Office on Women’s Health (OWH), U.S. Department of Health and Human Services (HHS), April 1, 2019.

Chapter 3 | The Genetics of Cancer

Chapter Contents

Section 3.1—Genetic Changes and Hereditary Cancer Syndromes

Section 3.2—BRCA Gene Mutations and Cancer Risk

Section 3.1 | Genetic Changes and Hereditary Cancer Syndromes

This section includes text excerpted from The Genetics of Cancer, National Cancer Institute (NCI), October 12, 2017. Reviewed January 2022.

Genetic Changes and Cancer

Cancer is a genetic disease – that is, cancer is caused by certain changes to genes that control the way our cells function, especially how they grow and divide.

Genes carry the instructions to make proteins, which do much of the work in our cells. Certain gene changes can cause cells to evade normal growth controls and become cancer. For example, some cancer-causing gene changes increase production of a protein that makes cells grow. Others result in the production of a misshapen, and therefore nonfunctional, form of a protein that normally repairs cellular damage.

Genetic changes that promote cancer can be inherited from our parents if the changes are present in germ cells, which are the reproductive cells of the body (eggs and sperm). Such changes, called germline changes, are found in every cell of the offspring.

Cancer-causing genetic changes can also be acquired during one’s lifetime, as the result of errors that occur as cells divide or from exposure to carcinogenic substances that damage deoxyribonucleic acid (DNA), such as certain chemicals in tobacco smoke, and radiation, such as ultraviolet rays from the sun. Genetic changes that occur after conception are called somatic (or acquired) changes.

There are many different kinds of DNA changes. Some changes affect just one unit of DNA, called a nucleotide. One nucleotide may be replaced by another, or it may be missing entirely. Other changes involve larger stretches of DNA and may include rearrangements, deletions, or duplications of long stretches of DNA.

Sometimes the changes are not in the actual sequence of DNA. For example, the addition or removal of chemical marks, called epigenetic modifications, on DNA can influence whether the gene is expressed – that is, whether and how much messenger ribonucleic acid (RNA) is produced. (Messenger RNA in turn is translated to produce the proteins encoded by the DNA.)

In general, cancer cells have more genetic changes than normal cells. But each person’s cancer has a unique combination of genetic alterations. Some of these changes may be the result of cancer, rather than the cause. As the cancer continues to grow, additional changes will occur. Even within the same tumor, cancer cells may have different genetic changes.

Hereditary Cancer Syndromes

Inherited genetic mutations play a major role in about 5 to 10 percent of all cancers. Researchers have associated mutations in specific genes with more than 50 hereditary cancer syndromes, which are disorders that may predispose individuals to developing certain cancers.

Genetic tests for hereditary cancer syndromes can tell whether a person from a family that shows signs of such a syndrome has one of these mutations. These tests can also show whether family members without obvious disease have inherited the same mutation as a family member who carries a cancer-associated mutation.

Many experts recommend that genetic testing for cancer risk be considered when someone has a personal or family history that suggests an inherited cancer risk condition, as long as the test results can be adequately interpreted (i.e., they can clearly tell whether a specific genetic change is present or absent) and when the results provide information that will help guide a person’s future medical care.

Cancers that are not caused by inherited genetic mutations can sometimes appear to run in families. For example, a shared environment or lifestyle, such as tobacco use, can cause similar cancers to develop among family members. However, certain patterns in a family – such as the types of cancer that develop, other noncancer conditions that are seen, and the ages at which cancer develops – may suggest the presence of a hereditary cancer syndrome.

Even if a cancer-predisposing mutation is present in a family, not everyone who inherits the mutation will necessarily develop cancer.

Here are examples of genes that can play a role in hereditary cancer syndromes.

The most commonly mutated gene in all cancers is TP53, which produces a protein that suppresses the growth of tumors. In addition, germline mutations in this gene can cause Li-Fraumeni syndrome (LFS), a rare, inherited disorder that leads to a higher risk of developing certain cancers.

Inherited mutations in the BRCA1 and BRCA2 genes are associated with hereditary breast and ovarian cancer syndrome, which is a disorder marked by an increased lifetime risk of breast and ovarian cancers in women. Several other cancers have been associated with this syndrome, including pancreatic and prostate cancers, as well as male breast cancer.

Another gene that produces a protein that suppresses the growth of tumors is PTEN. Mutations in this gene are associated with Cowden syndrome (CS), an inherited disorder that increases the risk of breast, thyroid, endometrial, and other types of cancer.

Genetic Tests for Hereditary Cancer Syndromes

Genetic tests for mutations that cause hereditary cancer syndromes are usually requested by a person’s doctor or other healthcare provider. Genetic counseling can help people consider the risks, benefits, and limitations of genetic testing in their particular situations.

A genetic counselor, doctor, or other healthcare professional trained in genetics can help an individual or family understand their test results and explain the possible implications of test results for other family members.

People considering genetic testing should understand that their results may become known to other people or organizations that have legitimate, legal access to their medical records, such as their insurance company or employer, if their employer provides the patient’s health insurance as a benefit. Legal protections are in place to prevent genetic discrimination, including the Genetic Information Nondiscrimination Act (GINA) of 2008 and the Privacy Rule of the Health Information Portability and Accountability Act (HIPAA) of 1996.

Section 3.2 | BRCA Gene Mutations and Cancer Risk

This section includes text excerpted from BRCA Gene Mutations: Cancer Risk and Genetic Testing, National Cancer Institute (NCI), November 19, 2020.

What Are BRCA1 and BRCA2?

BRCA1 (BReast CAncer gene 1) and BRCA2 (BReast CAncer gene 2) are genes that produce proteins that help repair damaged deoxyribonucleic acid (DNA). Everyone has two copies of each of these genes – one copy inherited from each parent. BRCA1 and BRCA2 are sometimes called tumor suppressor genes because when they have certain changes, called harmful or pathogenic variants or mutations, cancer can develop.

People who inherit harmful variants in one of these genes have increased risks of several cancers – most notably breast and ovarian cancer, but also several additional types of cancer. People who have inherited a harmful variant in BRCA1 and BRCA2 also tend to develop cancer at younger ages than people who do not have such a variant.

A harmful variant in BRCA1 or BRCA2 can be inherited from either parent. Each child of a parent who carries any mutation in one of these genes has a 50 percent chance (or 1 in 2 chance) of inheriting the mutation. Inherited mutations – also called germline mutations or variants – are present from birth in all cells in the body.

Even if someone has inherited a harmful variant in BRCA1 or BRCA2 from one parent, they would have inherited a normal copy of that gene from the other parent (i.e., because in most cases, embryos with a harmful variant from each parent cannot develop). But, the normal copy can be lost or changed in some cells in the body during that person’s lifetime. Such a change is called a somatic alteration. Cells that do not have any functioning BRCA1 or BRCA2 proteins can grow out of control and become cancer.

Role of BRCA1 or BRCA2 in Increasing the Risk of Breast and Ovarian Cancer?

A woman’s lifetime risk of developing breast and/or ovarian cancer is markedly increased if she inherits a harmful variant in BRCA1 or BRCA2, but the degree of increase varies depending on the mutation.

Breast cancer. About 13 percent of women in the general population will develop breast cancer sometime during their lives. By contrast, 55–72 percent of women who inherit a harmful BRCA1 variant and 45–69 percent of women who inherit a harmful BRCA2 variant will develop breast cancer by 70–80 years of age. The risk for any one woman depends on a number of factors, some of which have not been fully characterized.

Like women with breast cancer in general, those with harmful BRCA1 or BRCA2 variants also have an increased risk of developing cancer in the opposite (contralateral) breast in the years following a breast cancer diagnosis. The risk of contralateral breast cancer increases with the time since a first breast cancer, reaching 20–30 percent at 10 years of follow-up and 40–50 percent at 20 years, depending on the gene involved.

Ovarian cancer. About 1.2 percent of women in the general population will develop ovarian cancer sometime during their lives. By contrast, 39–44 percent of women who inherit a harmful BRCA1 variant and 11–17 percent of women who inherit a harmful BRCA2 variant will develop ovarian cancer by 70–80 years of age.

What Other Cancers Are Linked to Harmful Variants in BRCA1 and BRCA2?

Harmful variants in BRCA1 and BRCA2 increase the risk of several additional cancers. In women, these include fallopian tube cancer and primary peritoneal cancer, both of which start in the same cells as the most common type of ovarian cancer. Men with BRCA2 variants, and to a lesser extent BRCA1 variants, are also at increased risk of breast cancer and prostate cancer. Both women and men with harmful BRCA1 or BRCA2 variants are at increased risk of pancreatic cancer, although the risk increase is low.

In addition, certain variants in BRCA1 and BRCA2 can cause subtypes of Fanconi anemia, a rare syndrome that is associated with childhood solid tumors and development of acute myeloid leukemia. The mutations that cause these Fanconi anemia subtypes have a milder effect on protein function than the mutations that cause breast and ovarian cancer. Children who inherit one of these variants from each parent will develop Fanconi anemia.

Are Harmful Variants in BRCA1 and BRCA2 More Common in Certain Racial/Ethnic Populations than Others?

Yes. The likelihood of carrying an inherited mutation in BRCA1 or BRCA2 (the prevalence) varies across specific population groups. While the prevalence in the general population is about 0.2–0.3 percent (or about 1 in 400), about 2 percent of people of Ashkenazi Jewish descent carry a harmful variant in one of these two genes and the variants are usually one of three specific variants, called founder mutations. Other populations, such as Norwegian, Dutch, and Icelandic peoples,