p53 overexpression is a prognostic indicator in poorly differentiated, node negative and T1/T2 invasive ductal breast cancer patients

The present study evaluates the prognostic value of p53 protein overexpression assessed on histological sections of a retrospective series of 353 invasive breast carcinomas (294 invasive ductal carcinomas not otherwise specified, eight mucinous and 51 invasive lobular carcinomas), with a median follow-up of 10 years, using the polyclonal antibody CM1 and a cut-off score of> 10% of stained nuclei. p53 overexpression was not associated with invasive lobular or mucinous carcinomas (1.9% and 0% positive cases, respectively). In invasive ductal carcinomas (20.4% positive cases), there was a significant association between p53 overexpression and overall survival (P = 0.002), disease free interval (P = 0.005) and histological grade (P < 0.0001). Moreover, a statistically significant negative correlation between p53 immunoexpression and survival was found in high-grade (P = 0.016), pT1/2 (P = 0.001/0.018), and pN0 (P = 0.001) tumours, indicating its usefulness as a marker of prognosis in these subgroups of invasive ductal breast carcinoma.