Eligible for Breast-Conserving Therapy, Many Still Choose Mastectomy
No approved targeted therapies exist to treat triple-negative breast cancer, but new chemotherapeutic treatment strategies are helping shrink tumors so that less breast tissue needs to be removed during surgery. New research led by Brigham and Women's Hospital finds that breast-conserving therapy was successful in more than 90% of the women who became eligible for this procedure after treatment with chemotherapy. Despite these findings, 31% who were eligible for breast-conserving therapy chose to have the entire breast removed via mastectomy. These study findings were presented at the American Surgical Association's 135th Annual Meeting, held April 23, 2015, in San Diego (Abstract 3).
Reasons for Mastectomy Preference Are Unclear
“In general, if possible, we try to offer breast-conserving therapy as a preferred option for women with early-stage breast cancer,” said Mehra Golshan, MD, Director of Breast Surgical Services at Dana-Farber/Brigham and Women's Cancer Center. “One of the reasons we use chemo first is to potentially allow women who originally needed to have the entire breast removed because of more advanced disease to now be eligible for breast-conserving therapy. We see, though, that a significant number of patients who were eligible still ended up deciding to have their breast removed.”
The new work does not explain why patients and their surgeons made this choice. Previous studies have found that for those who are eligible for breast-conserving surgeries such as a lumpectomy, the rate of survival for patients who chose to have a lumpectomy is the same as for those who chose to have a mastectomy. A study by von Minckwitz et al found that in a German population, nearly 75% of patients underwent breast-conserving therapy for similar type tumors, much higher than the overall breast-conserving therapy rate of 47% reported in the current study.
“We don't have an answer for why this is the case, but we hope that this work encourages more patients and clinicians to think about why this is happening and what we can do to address this,” said Dr. Golshan, who is also Director of Breast Surgical Services at the Susan F. Smith Center for Women's Cancers at Dana-Farber Cancer Institute. “It's a work in progress.”
Study Results
The new study examined the impact of adding carboplatin and/or bevacizumab (Avastin), to the standard regimen of chemotherapy given to patients with triple-negative breast cancer. The team found a trend suggesting that the addition of one or both drugs increased the number of patients eligible for breast-conserving therapy.
“In triple-negative breast cancer patients, we continue to increase the complete pathologic response rate with our new drug combinations,” said David Ollila, MD, James and Jesse Distinguished Professor of Surgery at University of North Carolina School of Medicine, Co-Director of the UNC Breast Program, and a member of the UNC Lineberger Comprehensive Cancer Center. “On our trial, more patients were eligible for breast preservation. Despite these advances, more patients chose mastectomy as their surgical procedure. The reasons for this paradox need to be further explored.”
“A lot of things go into making this decision, but we must take into consideration the high likelihood of success in patients deemed candidates for breast-conserving therapies,” said Dr. Golshan.
Dr. Golshan and his colleagues note that they did not study specific patient or surgeon factors such as fear of cancer recurrence, or whether a patient harbored mutations in genes such as BRCA. Future studies could shed light on how these variables impact the choice between mastectomy and breast-conserving therapy.
Dr. Golshan is the corresponding author for this study.
This study was funded by the National Cancer Institute of the National Institutes of Health, the Breast Cancer Research Foundation, and Genentech.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
