Prognostic value of p53 expression in hormone receptor-positive and human epidermal growth factor receptor 2-negative breast cancer patients receiving neoadjuvant chemotherapy.

PURPOSE: The aim of this study was to determine whether the outcome to neoadjuvant chemotherapy (NAC) can be predicted by analyzing p53 expression in hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients. METHODS: We retrospectively reviewed 594 patients diagnosed with stage I-III HR-positive, HER2-negative breast cancer, and treated with NAC at the Asan Medical Center between 2008 and 2014. Expression of p53 was assessed, and overall survival (OS) and breast cancer-specific survival (BCSS) were investigated and compared between groups. RESULTS: At a median follow-up period of 69.8 months, OS and BCSS were higher in the p53-negative (p53(-)) group than in the p53-positive (p53(+)) group. Five-year OS was 95.4% in the p53(-) and 92.1% in the p53(+) group (p = 0.005). BCSS was 96.2% in the p53(-) group and 93% in the p53(+) group (p = 0.008). CONCLUSION: High expression of immunohistochemically detected p53 was strongly and significantly associated with decreased OS and BCSS than low p53 expression, suggesting that p53 may be a powerful prognostic factor in HR-positive, HER2-negative breast cancer patients receiving NAC.