Immunohistochemical status of p53 as prognostic factor in patients with node negative triple-negative breast cancer

Abstract

Background: TP53 mutations are the most common genomic alteration in TNBC, translation of p53 into the clinical setting is particularly pertinent in TNBC, with p53 mutations reported in over 60-88% of TNBC or BLBCs, compared with only 13-26% of luminal breast cancers. However, despite the high incidence of genetic alterations in breast cancer, there is no consensus about the clinical application of p53 to management breast cancer. Methods:We retrospectively reviewed the clinicopathologic records of patients diagnosed with surgically treated invasive breast cancer at Samsung Medical Center between Jan. 2003 and Apr. 2013. During these periods, 7739 patients with complete pathologic data, including tumor size, nuclear grade, multiple tumors, the presence of lymphovascular invasion (LVI), TNM stage, and the expression of estrogen receptor (ER), progesterone receptor (PR) and HER2, Ki-67 and p53 were included in the analysis. Results: Median follow-up duration of patients was 57 months (4-140 months). Median age of patients was 48 years (21-78 years) Of total 1129 patients, 732 patients (64.8%) had no LN metastasis and 397 patients had LN metastasis. In TNBC patients without LN metastasis, p53+ tumors had shown higher nuclear grade than p53- tumors (87.2% vs.81.5%, P = 0.034). And, p53+ tumors had shown higher EGFR expression than p53- tumors (90.7% vs. 84.8%, P = 0.039). With multivariate analysis, p53 expression (p53+) had shown significantly better OS than patients without p53 expression (p53-) (p53+ VS. p53-; HR 2.8, 95% confidence interval: 1.1-7.1, P = 0.022) . However, in patients with LN metastasis, p53+ expression was not associated with DFS, However, in TNBC patients with LN metastasis, there was no difference of clinicopathologic characteristics between p53+ tumors and p53- tumors. And, there was no association with survival, neither DFS nor OS. Conclusions: Conclusively, in TNBC, p53 expression was associated with better OS in patients with node-negative, not in patients with node-metastasis. These results suggest that p53 expression could be a favorable prognostic factor in early TNBC.