The survival benefit of neoadjuvant chemotherapy and pCR among patients with advanced stage triple negative breast cancer

Abstract

Triple negative breast cancer (TNBC) is an aggressive subtype that accounts for 15-20% of cases, with a higher incidence of relapse/death. Even with adjuvant chemotherapy, the 5 year distant metastasis-free survival rate remains low. A total of 452 tumor registry patients with TNBC and no evidence of metastatic disease were identified over the period of 1996-2011. The median age and follow-up time were 51 (range=21-88) and 3.9 (range=0.14-14) years. Approximately 75% of patients with stage III disease received neoadjuvant chemotherapy (NACT) compared with 47% for stage II. Patients with stage I disease predominantly received adjuvant chemotherapy (ACT). Among those who underwent NACT (n=202), 33% had a pathological complete response (pCR). Overall (OS) and disease-free (DFS) survival were significantly longer among patients achieving pCR (versus residual disease) following NACT (OS: all patients P<0.0001, stage II P<0.0001, stage III P=0.0062; DFS: all patients P<0.0001, stage II P=0.0011, stage III P=0.015). ACT was not associated with improved OS or DFS for stage III disease. Adjustment for age, chemotherapy, health insurance type, lymphovascular invasion, race, radiation, and surgery did not alter our results. These findings suggest that pCR following NACT is associated with improved survival among patients with TNBC, independent of diagnostic stage.