Metastatic site and p53 primary tumor expression in previously untreated stage IV breast cancer patients

p53 mutations have been reported to correlate with prognosis and response t o therapy in patients with different tumor types. However; although p53 sta tus is related to the primary tumor aggressiveness, an association between its expression and specific metastatic pattern has not yet been investigate d. We immunohistochemically analyzed p53 (Pab1801) and ki67 (mib1) primary tumor expression in a series of advanced breast cancer patients presenting a selected pattern of distant metastases at the time of first diagnosis. Fo rty-eight percent of the overall series was classified as p53 positive whil e 22% as mib1 positive tumors. The overall agreement between p53 and mib1 e xpression was statistically significant (p = 0.03). While mib1 primary tumo r expression did not show any association with the type of metastasis, p53 positivity, was significantly higher in patients with soft tissue metastasi s than in patients with bone or viscera metastasis (p = 0.002). No associat ion with the probability of clinical response or different overall survival was found for patients with different p53 or mib1 status either in the ove rall series of patients or in subgroups of eases with different sites of di stant metastasis.