BACKGROUND: Serum prostate-specific antigen (PSA) can be discovered in patients with breast cancer. We used ultrasensitive methods of PSA detection, successfully developed for early detection of PSA recurrence in prostatic-cancer patients, to study PSA in women with breast cancer and benign breast lesions before and after surgery. MATERIALS AND METHODS: Blood samples of 45 women with suspect breast findings were prospectively analyzed for PSA before and after breast surgery. Supersensitive 2nd and 3rd generation DPC assays were used to measure PSA (clinical detection limit of > 0.1 and > 0.02 ng/mL, respectively) and combined with concentration of serum to improve the clinical detection limit to > 0.025 and > 0.005 ng/mL, respectively. PSA concentrations were correlated with histological findings. RESULTS: The most sensitive detection was required to detect PSA preoperatively in 12 out of 45 patients, 8 (31%) out of 26 breast-cancer patients and 4 (25%) out of 16 patients with benign breast lesions. Postoperatively, 13 out of 45 patients were positive for PSA, 7 (27%) breast-cancer patients and 6 (23%) patients with benign breast lesions. CONCLUSIONS: Cancer patients showed the highest concentrations of PSA measured preoperatively and a decrease after surgery that was however not significant. Women with breast lesions expressed serum PSA in one third of the cases studied. PSA expression in serum does not distinguish benign from malignant breast diseases, but it might be valuable for follow-up to analyze whether recurrent disease can be detected with quantitative ultrasensitive PSA measurement.
