In a single-center study reported in JAMA Network Open, Kerollos Nashat Wanis, MD, PhD, and colleagues found that women with breast cancer and a pathogenic BRCA1/2 variant who underwent breast-conserving therapy had a 71% rate of 10-year bilateral mastectomy–free survival.
Kerollos Nashat Wanis, MD, PhD
Study Details
The study included 172 women with breast cancer identified from a prospectively maintained database who had pathogenic BRCA1/2 variants (BRCA1 = 92; BRCA2 = 80) and were treated with breast-conserving therapy from January 1977 to December 2021 at The University of Texas MD Anderson Cancer Center.
Key Findings
Among the 172 women, mean age was 47.1 ± 11.7 years, with 42 (24.4%) receiving their breast cancer diagnosis at < 40 years of age. Compared with women with BRCA2 variants, those with BRCA1 variants were younger at diagnosis and tended to have more advanced tumors that were more likely to be hormone receptor–negative and higher-grade.
Among all patients, at a median follow-up of 11.8 years (interquartile range = 5.7–18.2 years), 10-year rates were 70.7% (95% confidence interval [CI] = 63.3%–78.9%) for bilateral mastectomy–free survival (P = .23 for difference between BRCA1 and BRCA2) and 81.3% (95% CI = 74.4%–88.9%) for bilateral mastectomy due to cancer-free survival (P = .04 for BRCA2 vs BRCA1).
At 10 years, overall survival was 88.5% (95% CI = 83.1%–94.2%, P = .27 between variants) and distant disease–free survival was 87.0% (95% CI = 81.4%–92.3%, P = .52 between variants). The rate of ipsilateral breast cancer events was 12.2% (95% CI = 5.8%–18.2%, P = .16 between variants) and the rate of contralateral breast cancer was 21.3% (95% CI = 13.3%–28.6%, P = .19 between variants).
The cumulative incidence of ipsilateral and contralateral breast cancer events continued to increase through 20 years of follow-up.
The investigators concluded, “In this cohort study, although women with breast cancer and pathogenic BRCA1/2 variants treated with breast-conserving therapy had above-average risks of ipsilateral and contralateral breast cancer events, most did not have another cancer event and remained bilateral mastectomy–free. These findings may be useful for informing patients with BRCA variants choosing breast conservation.”
Henry M. Kuerer, MD, PhD, of the Department of Breast Surgical Oncology, The University of Texas MD Anderson Cancer Center, is the corresponding author for the JAMA Network Open article.
Disclosure: The study was supported by a Cancer Center Support Grant from the National Institutes of Health, which supports the Clinical Trials Support Unit, and others. For full disclosures of the study authors, visit jamanetwork.com.
