Purpose: Prostate-specific antigen (PSA), a glycoprotein initially thought to be produced only by the epithelial cells of the prostate, has recently been found in various tissues and tumors. It has been suggested that the expression of PSA in breast cancer is a good prognostic indicator and correlated with favorable prognosis. However, in recent years opposite results have been reported. In this study, we investigated the immunoreactivity of PSA in female breast cancer to find out any relationship between PSA and prognostic parameters.
Patients and methods: Sections of formalin-fixed, paraffin- embedded samples from 109 invasive ductal carcinomas were immunostained for PSA. The staining results were analyzed in relation to age, tumor size, histologic grade, axillary lymph node status and steroid receptors.
Results: PSA immunoreactivity was seen in only 11 (10.1%) out of 109 cases. All PSA positive cases were also estrogen (ER) and progesterone receptor (PR) positive. We found a statistically significant correlation between PSA and the expression of steroid receptors, while no correlation was detected with the other factors.
Conclusion: The detection of PSA, using immunohistochemistry, does not seem to be a reliable prognostic criterion for female breast cancer patients or a marker of tumor origin.