Overall Survival Following Neoadjuvant Chemotherapy Versus Adjuvant Chemotherapy in Clinically Node Negative T1 Triple Negative Breast Cancer

Background: The purpose of this study was to compare the overall survival (OS) of upfront surgery followed by adjuvant chemotherapy (ACT) versus neoadjuvant chemotherapy (NACT) followed by surgery in patients with clinical T1 clinically node negative triple negative breast cancer (TNBC). Patients and Methods: We retrospectively reviewed 48,329 women with cT1N0 TNBC from 2006 to 2016 in the National Cancer Database (NCDB). Patients were categorized into five pathologic subgroups based on ACT versus NACT and definitive pathologic stage after surgery: ACT with unchanged stage (pT0–1N0), ACT with pathologic upstage (any nodal disease, > pT1N0), NACT with pCR (ypT0–isN0), NACT with stable disease (SD) (ypT1N0), and NACT with progressive disease (PD) (any nodal disease, > ypT1N0). The primary outcome was 5 year OS. Results: Patients with TNBC who underwent upfront surgery followed by ACT had better OS compared with those who received NACT (p < 0.001). The hazard ratio (HR) for death for NACT compared with ACT was 1.42 (95% CI 1.26–1.59, p < 0.001) on multivariate analysis. Patients who underwent upfront surgery followed by ACT and whose pathological stage was unchanged from clinical stage had similar outcomes compared with those who received NACT and attained pCR with 5 year OS of 92.7% versus 93.3% (p = 0.34). Patients with clinical T1cN0 tumors who underwent NACT with pCR had better outcomes compared with those who underwent ACT with unchanged stages. (p = 0.025). Conclusions: For cT1N0 TNBC patients, OS of upfront surgery followed by ACT was not inferior to those who underwent NACT. Neoadjuvant chemotherapy was associated with better outcomes in cT1c patients who attained pCR.