Modern, multimodality lumpectomy treatment significantly reduces the incidence of breast cancer recurrence at the original tumor site compared to historical protocols, according to a new study presented at the American Society of Breast Surgeons (ASBrS) 19th Annual Meeting (Abstract 403956). The study involved more than 6,000 patients treated with breast-conserving surgery in nine clinical trials during a 14-year period.
“While survival rates are equal, lumpectomy traditionally carries a greater risk of local recurrence than mastectomy, and many women face a difficult trade-off when making treatment decisions. This more positive, contemporary data may make their choice a little easier,” said lead researcher Heather Neuman, MD, of the University of Wisconsin School of Medicine and Public Health, who analyzed patient information aggregated through trials conducted by the Alliance for Clinical Trials in Oncology. She noted that during the last decade, breast cancer therapies have become more effective and personalized for the patient’s particular disease profile, but studies on recurrence are rare because reliable data is extremely difficult to track over time. With more detailed and controlled clinical trial information, this new research fills an important information gap and provides a timely, much-needed analysis of local recurrence rates among various breast cancer subtypes.
Overall, the study found a 4.2% local recurrence rate for women who had breast-conserving surgery and modern-era chemotherapy or other systemic therapies, along with radiation treatment. “This compares with the generally accepted figure of about 5% to 10% for lumpectomy recurrence, which is typically based on older treatment protocols,” commented Dr. Neuman.
Noting that breast tumors differ in molecular characteristics, she emphasized that cancer profiles play an important role in the course and treatment of the disease, including in whether a cancer is likely to return. In this study, recurrence was lowest among estrogen receptor (ER)/progesterone receptor (PR)/HER2-positive cancers (3%), followed by ER/PR-negative, HER2-positive (4.7%) disease. The highest rate was for ER/PR-negative, HER2-negative cells (6.9%). “Because of the challenges in obtaining data, this is perhaps the only study to examine the relationship of recurrence and receptor subtype in the era of modern breast cancer therapy,” noted Dr. Neuman.
In addition to greater surgical precision, modern advances in breast conservation therapies also include more effective radiation therapy and chemotherapy, which is often optimized for the specific tumor characteristics as knowledge of breast cancer biology grows. Dr. Neuman noted that the latter has likely had the greatest impact in preventing tumor recurrence. In addition, specialized drug therapies targeting more aggressive HER2-positive cancers have significantly improved outcomes and minimized tumor recurrences.
“Clearly, this new data shows that recurrence with breast conservation has diminished significantly overall,” concluded Dr. Neuman. “Additionally, in today’s age of multimodality, personalized breast cancer therapy, stratifying recurrence risk by cancer subtypes helps women and their physicians to make more informed decisions. This study absolutely has added important new information to my conversations with patients about the relative risks and benefits of lumpectomy and mastectomy.”
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