Pathological response and survival after neoadjuvant therapy for breast cancer: a 30-year study.

PURPOSE OF THE RESEARCH: HER2-positive and triple-negative breast cancer (TNBC) still have a poor prognosis. Pathological complete response (pCR) is usually considered a surrogate marker for outcome. The aim of this study was to reconsider these parameters on a large population after a long follow-up. 348 patients with unilateral breast cancer who received neoadjuvant treatment at our institution over 30 years were included.

RESULTS: Patients were classified according to hormonal receptors (HR) and HER2. Median follow-up was 7 years. pCR was significantly lower in HR+/HER2- tumors (P < 0.0001). The 7-year OS rates were 76.1% (HR+/HER2-), 60.1% (TNBC), 72.4% (HR+/HER2+), and 49.9% (HR-/HER2+). Disease-free survival (DFS) and OS differed significantly according to pCR. Among HER2+ patients, pCR rate, DFS and OS were greater with trastuzumab.

CONCLUSIONS: TNBC and HR-/HER2+ tumors have the worst outcome. pCR remains a significant prognostic factor. Trastuzumab strongly improves pCR and survival in HER2+ tumors.