Triple-negative breast cancer (TNBC) presents a high risk breast cancer that lacks the benefit from hormone treatment, chemotherapy is the main strategy even though it exists in poor prognosis. Use of adjuvant radiation therapy, which significantly decreases breast cancer mortality, has not been well described among poor TNBC women. The aim of this study was to evaluate whether the combination of chemotherapy and radiotherapy could significantly increase survival outcomes in TNBC women after mastectomy.

A prospective randomized controlled multi-center study was performed between February 2001 and February 2006 and comprised 681 women with triple-negative stage I-II breast cancer received mastectomy, of them, 315 cases received systemic chemotherapy alone, 366 patients received radiation after the course of chemotherapy. Recurrence-free survival (RFS) and overall survival (OS) were estimated. Simultaneously local and systemic toxicity were observed.

After a median follow-up of 86.5 months, five-year RFS rates were 88.3% and 74.6% for adjuvant chemotherapy plus radiation and adjuvant chemotherapy alone, respectively, with significant difference between the two groups (HR 0.77 [95% CI 0.72, 0.98]; P=0.02). Five-year OS significantly improved in adjuvant chemotherapy plus radiation group compared with chemotherapy alone (90.4% and 78.7%) (HR 0.79 [95% CI 0.74, 0.97]; P=0.03). No severe toxicity was reported.

Patients received standard adjuvant chemotherapy plus radiation therapy was more effective than chemotherapy alone in women with triple-negative early-stage breast cancer after mastectomy.