Immunohistochemical detection of mutant p53-suppressor gene product in patients with breast cancer: influence on metastasis-free survival.

Overexpression of p53-protein appears to be a common event in primary breast cancer. It has been proposed that the presence of elevated levels of this protein may be an independent prognostic factor and may be important for the ability of a tumor to metastasize. This study was performed to evaluate the influence of immunohistochemically detectable mutant p53-protein on metastasis-free survival of patients with breast cancer. Immunohistochemistry was performed on 117 paraffin-embedded biopsy specimens of consecutive patients with stage T1-T4 breast cancer, using a monoclonal antibody against p53 suppressor gene product. 29 (24.8%) specimens showed positive staining, whereas in 88 (75.2%) a negative staining reaction for p53 was found. Comparing time intervals to diagnosis of metastasis, using Kaplan-Meier curves, Log-Rank test revealed no significant differences in metastasis-free survival between p53 positive and negative patients (P = 0.32), whereas statistically significant differences were noted for tumor stage (P < 0.01), nodal status (P < 0.01), histological grading (P < 0.01) and estrogen receptor status (P = 0.03). Mutant p53-protein, as detected by immunohistochemistry in paraffin embedded tumor tissue, does not appear to influence metastasis-free survival in patients with breast cancer.