p53 as a specific prognostic factor in triple-negative breast cancer.

OBJECTIVE A recent suggestion is that the predictive value of a single biomarker may rely on the genetic background on the tumor and that different breast cancer subgroups may have different predictive markers of response to chemotherapy. The prognostic value of p53 in the outcome of adjuvant anthracycline-containing chemotherapy was evaluated according to molecular subclasses defined using the expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. METHODS Subjects were patients (n = 135) with invasive ductal carcinoma treated with adjuvant anthracycline-based chemotherapy between 1994 and 2000 in our hospital. Clinico-pathological features were reviewed by retrospective examination of medical records. RESULTS Overall survival rate was not independently predictive by p53 status (P = 0.182). However, in triple-negative cases, there was statistically significant survival difference (P = 0.034) and no statistically significant difference (P = 0.783) in non-triple-negative cases by p53 status. In the Cox proportional hazard analysis, p53 was also strongly predictive for relapse-free survival (P = 0.013) and overall survival (P = 0.049) in triple-negative patients. CONCLUSIONS p53 status could be a specific prognostic factor in triple-negative breast cancer patients treated by adjuvant anthracycline-based regimen. When p53 is positive in triple-negative breast cancer, we could expect poor survival, prompting aggressive or alternative treatment.