In this podcast, we’ll discuss one study highlighted at the 2014 Breast Cancer Symposium that presents research on breast cancer recurrence after chemotherapy given before surgery.
ASCO: You’re listening to a podcast from Cancer.Net (Cancer dot Net). This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the world’s leading professional organization for doctors that care for people with cancer.
In today’s podcast, we’ll discuss one study highlighted at the 2014 Breast Cancer Symposium that presents research on breast cancer recurrence after chemotherapy given before surgery. This podcast will be led by Dr. Amy Early, who is a clinical professor of medicine at the University of Buffalo School of Medicine and Biomedical Sciences and Associate Professor of Oncology at Roswell Park Cancer Institute. Dr. Early is also a member of the Board of Directors and chair of the Consensus Committee of the American Society for Breast Disease and a member of the News Planning Team for the 2014 Breast Cancer Symposium. ASCO would like to thank Dr. Early for summarizing this research.
Dr. Early: This is Dr. Amy Early from the news planning team of the 2014 Breast Cancer Symposium of the American Society of Clinical Oncology. I am clinical professor of medicine and a breast oncologist at Roswell Park Cancer Institute in Buffalo, New York. I have the pleasure to discuss a presentation at the symposium on Thursday, September 4th in San Francisco by Dr. Terry Mamounas and his colleagues. Dr. Mamounas is professor of surgery at the University of Central Florida and medical director of the comprehensive breast program at the University of Florida Health Cancer Center in Orlando, Florida.
Abstract 61 is titled “Local regional recurrence after neoadjuvant chemotherapy: pooled analysis from the collaborative trials in neoadjuvant breast cancer. This study is an analysis from 12 large clinical trials that finds that the breast cancer’s response to chemotherapy when given before surgery, called neoadjuvant chemotherapy, and tumor subtype, are strong predictors of local and regional breast cancer recurrence.
Local regional recurrences are a reappearance of the tumor in the breast or nearby areas such as the axillary – that is, the underarm – lymph nodes and the chest wall. According to researchers, response to chemotherapy and knowledge of tumor subtypes based on hormone receptors like estrogen receptor and progesterone receptor and HER2 may be more informative than tumor stage at diagnosis. This is the largest study of its kind to date.
Neoadjuvant chemotherapy is given before breast surgery to women with locally-advanced but not metastatic breast cancer to make tumors operable. The strategy is also used to downsize tumors too large for lumpectomy to permit later lumpectomy for women who wish breast conservation. An advantage of receiving chemotherapy before surgery is that it can shrink and often eradicate the tumor in the breast and underarm lymph nodes and potentially reduce the need for mastectomy, lymph node removal, and radiation therapy after surgery.
Neoadjuvant chemotherapy can also help better identify women at higher risk for recurrence who may benefit from the addition of radiation therapy and those at low risk who may not need it, according to Dr. Mamounas.
Researchers assessed 1,995 women with stages I to III breast cancer who were treated with chemotherapy before surgery in clinical trials conducted in the United States and Europe with a median follow-up time of 5.4 years. The overall proportion of women with local regional recurrence was 8.3 percent. At the time of surgery, women who had persistence of cancer in the breast or axillary lymph nodes after neoadjuvant chemotherapy had an increased risk of local regional recurrence compared to women who had complete disappearance of cancer. Those with residual cancer in the breast and no cancer in the axillary lymph nodes had a 1.6 times higher risk of local regional recurrence. Those with persisting cancer in the axillary lymph nodes or breast had a 2.8 times higher risk of recurrence.
The effective pathologic complete remission and disappearance of all detectable tumor was evident in patients treated with mastectomy and in those treated with lumpectomy plus breast radiotherapy. Local regional recurrences also differed by tumor subtype. The five-year risk of local regional recurrence for women with hormone receptor positive, HER2 negative, grade 1 or 2 cancers was 4.2 percent. Women with other cancer subtypes had higher recurrence risk. The risk for women with hormone receptor positive, HER2 negative but grade 3 cancers was 9.7 percent. The risk for women with triple negative cancer was 12.2 percent. And the risk for women with hormone receptor negative but HER2 positive cancers was 14.8 percent.
Interestingly, more advanced stage at diagnosis did not adversely affect rate of local regional recurrence when pathologic response to neoadjuvant chemotherapy was complete and tumor subtype was taken into account.
Dr. Mamounas stated that while more research is needed, the findings of this study provide additional information for doctors and patients to consider when deciding on the best local regional treatment options after neoadjuvant chemotherapy and surgery.
The news planning team of ASCO considers this to be a highly important study that will impact clinical decision making and future clinical trials.
ASCO: Thank you, Dr. Early. More information from the 2014 Breast Cancer Symposium can be found at www.cancer.net, including additional podcasts covering other highlighted research from this event. Cancer.Net is supported by the Conquer Cancer Foundation, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high-quality cancer care. Thank you for listening to this Cancer.Net Podcast.