Prognostic value of immunohistochemically detected p53 in adjuvant chemotherapy-treated triple negative breast cancer.

Mutations of the p53 gene are the most common genomic alterations associated with triple-negative breast cancer (TNBC) and are reported in 60-88% cases. Despite the high incidence of such mutations, there is no consensus about the clinical application of p53 detection in breast cancer management. This study investigates the prognostic value of immunohistochemically detected p53 in TNBC patients who received adjuvant chemotherapy. We reviewed the clinicopathologic features of 1088 TNBC patients who received curative surgery and adjuvant chemotherapy. Immunohistochemically, nuclear staining of >10% was defined as p53 "positive." Of the total 1088 TNBC patients, 709 (65.2%) had no lymph node metastasis (N0). Among the N0 patients, 408 (57.5%) were p53- positive (p53+), and 301 (42.5%) were p53- negative (p53-). p53 + tumors showed a tendency for better breast cancer-specific survival (BCSS, p = 0.052) and overall survival (OS, p = 0.079) compared to p53- tumors. In multivariate analysis, p53 + tumors showed significantly better BCSS (p53 + vs. p53-; HR 2.8, 95% confidence interval: 1.1-7.3, p = 0.034); however, in TNBC patients with lymph node metastasis, there was no correlation between p53 status, clinicopathologic characteristics, and survival. Consequently, in TNBC patients who received adjuvant chemotherapy, immunohistochemical p53 expression was associated with better BCSS in N0 patients.