Evaluation of the Survival Benefit of Different Chemotherapy Regimens in Patients with T1-2N0 Triple-Negative Breast Cancer

PURPOSE This study aimed to evaluate the survival benefit of different adjuvant chemotherapy regimens in patients with T1-2N0 triple-negative breast cancer. METHODS Of 67,321 patients who were registered in the Korean Breast Cancer Society nationwide database between January 1999 and December 2008, 4,033 patients with T1-2N0 triple-negative breast cancer were included. The overall survival of patients who did not receive adjuvant chemotherapy was compared with those treated with adjuvant anthracycline and cyclophosphamide (AC), 5-fluorouracil, anthracycline, and cyclophosphamide (FAC), or cyclophosphamide, methotrexate, and 5-fluorouracil (CMF). RESULTS The median follow-up was 52.5 months. Chemotherapy was used in 87.4% of patients; it was used more commonly in patients with T2 tumors, those who were younger, had a higher histologic grade, and who showed lymphovascular invasion. The 5-year cumulative overall survival rate was 95.4%. Younger age, breast-conserving surgery, and adjuvant chemotherapy were significantly associated with improved overall survival. The 5-year cumulative overall survival rate of patients who did not receive adjuvant chemotherapy and those treated with AC, FAC, and CMF were 92.5%, 95.9%, 95.3%, and 95.9%, respectively. On multivariate analysis, the administration of any adjuvant chemotherapy regimen was significantly associated with improved overall survival (p=0.038). No significant difference in survival benefit was observed among the three different treatment groups. CONCLUSION A standard adjuvant chemotherapy regimen with the least drug-related toxicity might be a reasonable treatment for patients with T1-2N0 triple-negative breast cancer.