Clinical implication of p53 overexpression in breast cancer patients younger than 50 years with a triple-negative subtype who undergo a modified radical mastectomy.

OBJECTIVE: The purpose of this study was to identify the clinicopathological characteristics and prognostic value of p53 overexpression in breast cancer patients treated with a modified radical mastectomy.

METHODS: The medical records of 197 patients who had undergone modified radical mastectomy between January 1991 and December 2008 were reviewed retrospectively. Breast cancer subtype and p53 overexpression were investigated using immunohistochemistry and/or fluorescent in situ hybridization analysis of surgical specimens.

RESULTS: The median follow-up after the modified radical mastectomy was 56.1 months (range, 14.7-232.7). The median age was 47 years (range, 31-72). p53 overexpression was noted in 73 patients (37.1%). Breast cancer-specific death rate (P = 0.011), cancer progression (P = 0.024), distant metastasis (P = 0.015), hormone receptor negativity (P < 0.001) and human epidermal growth factor receptor 2 positivity (P = 0.017) were detected more frequently in patients with p53 overexpression. The overall survival rates were significantly lower in the p53-overexpression group than in the non-p53-overexpression group (P = 0.021, log-rank test). In the multivariate analysis, p53 overexpression showed the strongest prognostic significance in patients aged <50 years (P = 0.039) and with the triple-negative subtype (P = 0.023).

CONCLUSIONS: p53 overexpression correlated with breast cancer-specific death rates and adverse prognostic factors in patients treated with modified radical mastectomy. p53 overexpression might be a more reliable prognosticator in patients aged <50 years and with the triple-negative subtype. More effective systemic treatments might be warranted for these patients exhibiting p53 overexpression. Further validation is required to make more definite conclusions.