Prostate specific antigen (PSA) in breast and ovarian cancer

Prostatic specific antigen (PSA) is commonly used for the diagnosis and monitoring of prostatic adenocarcinoma, and has recently been detected in breast cancer and it is also thought to be produced by ovarian cancer. To examine the prognostic value of PSA tumor expression, we investigated the tumor cytosols of 26 patients with breast cancer and of 16 women with ovarian cancer. We used a chemiluminescence immunoassay for the quantitative determination of PSA (detection limit 0.003 ng/ml). The median PSA level in breast cancer patients was 0.31 ng/mg (minimum 0.003, maximum 4.4). PSA expression was significantly lower in poorly differentiated breast cancers compared to moderately and highly differentiated tumors. Advanced lymph node metastases were also correlated with lower PSA expression. We found no correlation with relapse free or overall survival. Median PSA level in our ovarian cancer patient collective was 0.014 ng/mg (minimum 0.003, maximum 0.046). We found a significant correlation between PSA expression and the estrogen receptor content of the tumor. PSA expression showed no correlation with histological grading, tumor size or other tumor characteristics in ovarian cancer. There was no correlation with relapse free or overall survival in ovarian cancer patients. Our study demonstrates that PSA is expressed in ovarian malignancies but at a lower level compared to breast cancer tissue. PSA was not able to identify a subset of patients with good prognosis in breast and in ovarian cancer patients.