An interview with Dr. Neelima Denduluri from Virginia Cancer Specialists, U.S. Oncology in Arlington, VA and Dr. Sharon Giordano from the University of Texas MD Anderson Cancer Center in Houston, TX on "Selection of Optimal Adjuvant Chemotherapy and Targeted Therapy for Early Breast Cancer: ASCO Guideline Update." This update addresses the use of adjuvant trastuzumab emtansine and the use of biosimilar forms of trastuzumab. Read the full guideline at www.asco.org/breast-cancer-guidelines. Transcript ASCO: The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care, and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. Brittany Harvey: Hello and welcome to the ASCO Guidelines podcast series brought to you by the ASCO podcast network, a collection of nine programs covering a range of educational and scientific content, and offering enriching insight into the world of cancer care. You can find all the shows, including this one, at podcast.asco.org. My name is Brittany Harvey, and today I'm interviewing Dr. Neelima Denduluri from Virginia Cancer Specialists, US Oncology in Arlington, Virginia, and Dr. Sharon Giordano from the University of Texas M.D. Anderson Cancer Center in Houston, Texas, co-chairs on "Selection of Optimal Adjuvant Chemotherapy and Targeted Therapy for Early Breast Cancer: ASCO Guideline Update." Thank you for being here, Dr. Denduluri and Dr. Giordano. Dr. Neelima Denduluri: Thanks for having us. Dr. Sharon Giordano: Yeah, we're delighted to be here. Thank you. Brittany Harvey: First, I'd like to note that ASCO takes great care in the development of its guidelines and ensuring that the ASCO conflict of interest policy is followed for each guideline. The full conflict of interest information for this guideline panel is available online with the publication of the guideline in the Journal of Clinical Oncology. Dr. Denduluri, do you have any relevant disclosures that are related to this guideline topic? Dr. Neelima Denduluri: Our institution has received research funding from companies including Genentech. Brittany Harvey: Thank you. And Dr. Giordano, do you have any relevant disclosures that are related to this guideline topic? Dr. Sharon Giordano: No, I don't have any relevant disclosures. Thank you. Brittany Harvey: Thank you. Then let's get into the guideline content. Dr. Denduluri, what prompted this focused update of the selection of optimal adjuvant chemotherapy and targeted therapy for early breast cancer guideline? Dr. Neelima Denduluri: There was an FDA meta analysis and several other studies that showed that patients that did not receive a pathologic complete response after preoperative therapy in the HER2-positive setting had a worse prognosis. In the past, we didn't have actionable findings to improve their outcome. But there was a trial, the KATHERINE trial, that randomized patients that received chemotherapy and trastuzumab, plus or minus pertuzumab, that did not achieve a pathologic complete response to receive standard of care trastuzumab or 14 cycles of trastuzumab emtansine. And the patients that received trastuzumab emtansine had a significantly improved outcome over those that received standard of care trastuzumab. These were very impactful findings that changed care for women with early breast cancer. Therefore, we wanted to update the guideline. Brittany Harvey: So Dr. Giordano, there are two new recommendations in this guideline update. First, what does the guideline say regarding the use of adjuvant trastuzumab emtansine following standard preoperative chemotherapy and HER2-targeted therapy for patients with HER2-positive breast cancer with residual invasive cancer in the breast or lymph nodes at surge