Trends in rates of modified radical mastectomies and bilateral mastectomies in unilateral breast cancer.

Abstract

569 Background: Women with unilateral breast cancer (BC) without genetic predisposition have a low risk for local and contralateral recurrence with breast conservation surgery (BCS) and adjuvant treatment. We aimed to study the pattern of surgical care across centers in rural New Mexico and its correlation to clinical outcomes. Methods: We retrospectively evaluated 533 patients with Stage 1-3 BC diagnosed between January 1989 to October 2015. Clinical Outcomes with BCS, sentinel lymph node dissection (SLND), simple mastectomy (SM), modified radical mastectomy (MRM) and Bilateral Mastectomy (BM) were studied. Descriptive statistics were performed to describe the proportion of surgery types. Predictors of clinical outcomes were evaluated by multivariate logistic regression. Results: Out of 533 patients, 510 (82%) had early stage (0-3) resectable BC. Among these, 48% (246/510) had either MRM (209/510) or BM (37/510). MRM was performed in 3% of stage 0 (6/209), 23% (49/209) stage I, 46%(97/209) of stage II and 27% (57/209) of Stage III patients. Overall, the rate of SLND was 42% among Early stage Breast cancer. Of 41 patients treated with bilateral mastectomy, 10 were positive for BRCA mutation, 6 for family history and 3 for contralateral disease. Median age of BM was 53 +12 y. The local recurrence rate was 8.8% (45/510), and metastatic recurrence rate was 15.5% (79/510). Lymphedema rate was 9.2% (47/510). Using MRM as reference, the Odds Ratio (OR) for lymphedema after BM and BCT were 2.15 (95% CI, 0.84-5.50) and 0.58 (0.28-1.22), respectively. With 9.6 years of median follow up, the predictive probabilities of lymphedema after BCT, SM, MRM and BM were 1%, 4%, 9% and 18%. The OR for local recurrence in women with BCT were 1.46 (95th C/I: 0.72-2.95), SM 0.27 (0.03-2.13), BM 2.06 (95th C/I:0.70-6.06). Conclusions: Less BCT and more aggressive procedures are being performed, and the latter is associated with more lymphedema. No significant differences were noted in local recurrences. Presence of a genetic mutation was not the sole indicator of BM’s in our patient population. There is a need for evidence-based shared decision-making and surgical management of breast cancer, especially in a rural community setting.