Patients who undergo mastectomy (MS) may have significantly decreased survival compared with patients who undergo breast-conserving surgery (BCS), according to a study published in the Journal of Global Oncology.

Previously conducted trials have provided evidence that there is no difference in overall survival (OS) whether patients undergo BCS or MS; however, recent studies are demonstrating that BCS is associated with improved overall survival. 

The authors of the study analyzed the survival results of 7609 patients with breast cancer from 9 institutions in India and stratified them by cancer stage, and investigated the effect of BCS or MS on overall survival.

Overall 5-year survival rates were significantly improved in patients with stage II breast cancer who underwent BCS compared with those who underwent MS (94.0% vs 85.8%, respectively; adjusted hazard ratio [HR], 2.40; 95% CI, 1.8-3.2). In patients with stage III breast cancer, overall 5-year survival rates were also significantly improved in those who underwent BCS vs MS (87.1% vs 69.0%, respectively; HR, 2.82; 95% CI, 2.2-3.7).

Patients who underwent MS had improved OS with systemic therapy (chemotherapy and/or hormone therapy), whereas patients who underwent BCS had the best overall survival when receiving radiation therapy only.

The investigators conclude that “the reasons for lower survival with MS and the biologic or scientific rationale of the necessity of systemic therapy to achieve optimal survival in patients undergoing MS but not in those with BCS need further investigation.” 

Reference

1. Nandakumar A, Rath GK, Kataki AC, et al.Decreased survival with mastectomy vis-à-vis breast-conserving surgery in stage II and III breast cancers: a comparative treatment effectiveness study. J Glob Oncol. 2017;3(4):304-313.