The effect of immunohistochemically detected p53 accumulation in prognosis of breast cancer; A retrospective survey of outcome.

BACKGROUND: P53; a tumor suppressor gene has known to have a role in a group of human cancers. Its role in breast cancer; one of the most prevalent malignancies worldwide, is still controversial. The current study is designed to evaluate the prognostic role of p53 mutation in breast cancer.

METHODS: one hundred and eighty five breast cancer patients were studied in this retrospective study. P53 mutation was detected by accumulation of p53 protein in the patients' pathology samples. Immunohistochemistry (IHC) was used to detect the protein. The effect of p53 on the final outcome was assessed using Kaplan-Meier estimate of survival and compared by log-rank test. Prognostic effects analyzed by cox proportional hazard models.

RESULTS: while the stage of the disease at presentation was not significantly different between p53 positive and negative patients, those with p53 mutation had a significantly poorer outcome in terms of overall and disease-free survival rates (OS and DFS). In a multivariate analysis hazard ratio of p53 mutation was about 5 and 3.8 for OS and DFS respectively. They also had a higher cumulative incidence of relapse.

CONCLUSION: It seems that p53 mutation is an independent prognostic factor for breast cancer. Although larger prospective studies are needed to clarify the importance of such a conclusion.