A STUDY OF local recurrence rates following lumpectomy has shown significant improvement in patients receiving modern, multimodal therapies, suggesting breast-conserving surgery may be an option for more patients with breast cancer, according to data presented at the 2018 American Society of Breast Surgeons (ASBrS) Annual Meeting.1 In a cohort of nearly 7,000 patients treated and followed in 9 clinical trials, 5-year local recurrence rates after breast-conserving surgery were 4.2%. The researchers noted that this is the first study to examine the relationship of recurrence and tumor subtype in the setting of “modern-era” therapy.
Heather B. Neuman, MD, MS, FACS
“Our study demonstrates that in the modern era, the rate of local recurrence after breast-conserving surgery is quite low—lower than what’s often been used historically to counsel women,” said Heather B. Neuman, MD, MS, FACS, Associate Professor of Surgical Oncology at the University of Wisconsin School of Medicine and Public Health, Madison. “These modern era-estimates should be used to inform discussions between patients and surgeons regarding the decision between breast conservation and mastectomy.”
Study Background
AS DR. NEUMAN reported at a press briefing in advance of the ASBrS meeting, multiple randomized controlled trials have demonstrated equivalent survival between breast conservation and mastectomy, albeit with a higher local recurrence rate after breast conservation. Until now, generally accepted rates of recurrence were 5% to 10% following lumpectomy, the authors noted, but these rates reflect historical data associated with the use of older breast cancer treatment protocols.
“As a result of multimodal treatment, the absolute rates of local recurrence have been declining,” said Dr. Neuman. “During the past decade, breast cancer therapies have become more effective and personalized for a patient’s particular disease profile, but studies on how this impacts cancer recurrence are rare because reliable recurrence data are extremely difficult to track over time.”
“In today’s age of multimodality and personalized breast cancer therapy, stratifying recurrence risk by cancer subtypes helps women and their physicians to make more informed decisions.”— Heather B. Neuman, MD, MS, FACS
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For this meta-analysis, Dr. Neuman and colleagues evaluated local recurrence rates after breast-conserving surgery in a cohort of patients receiving modern-era therapy within the context of a clinical trial. The researchers used data from nine Alliance for Clinical Trials in Oncology legacy clinical trials, which enrolled women diagnosed with stage I to III breast cancer between 1997 and 2011. Women who had undergone breast-conserving surgery as well as state-of-the-art systemic and radiation therapies (N = 6,927) were included. Multivariable Cox proportional hazards models were used to identify factors associated with time to local recurrence, including patient age, tumor size, lymph node status, and molecular tumor subtype.
Recurrence Rates ‘Significantly Diminished’
AS DR. NEUMAN reported, the overall rate of local recurrence after lumpectomy at 5 years from trial registration was 4.2%, but researchers observed variations based on receptor type. Data showed that recurrence rates were highest for patients with triple-negative disease (6.9%) and lowest for triple-positive patients (3%). For patients with estrogen receptor–negative, HER2-positive disease, the recurrence rate was 4.7%.
Following multivariate analysis that controlled for age, tumor size, and nodal status, receptor type remained strongly associated with local recurrence. Additionally, older age was associated with a lower risk of local recurrence, and the presence of more positive nodes was associated with a higher risk of local recurrence.
Dr. Neuman acknowledged these rates are higher than local recurrence rates following mastectomy but noted the latter are “more difficult to assess” due to a heterogeneous patient population. According to the authors, this is the only study to examine the relationship of recurrence and receptor subtype in the era of modern breast cancer therapy because of the challenges in obtaining data.
“For early-stage breast cancer, the risk of a local recurrence is 1% or lower with mastectomy, but this increases with more advanced cancer,” said Dr. Neuman. “These data are patient-specific based on initial, presenting tumor characteristics.”
She concluded, “Clearly, these new data show that recurrence with breast conservation has diminished significantly overall. In today’s age of multimodality and personalized breast cancer therapy, stratifying recurrence risk by cancer subtypes helps women and their physicians to make more informed decisions.” ■
DISCLOSURE: Dr. Neuman reported no conflicts of interest.
REFERENCE
1. Neuman H, Schumacher J, Hanlon B, et al: Local recurrence rates after breast-conserving therapy in patients receiving modern era therapy. 2018 American Society of Breast Surgeons Annual Meeting. Abstract 403956. Presented May 4, 2018.
