Case-control study of predictive level of prostate specific antigen (PSA) cutoff point

Objective: To assess the predictive level of PSA 4 ng/ml (cutoff point).

Methods: 158 pathological confirmed cases of prostate cancer and 71 biopsy confirmed controls without prostate cancer were obtained from Urology Department. Exclusion criteria were persons with: immunodeficiency diseases, other cancer, advanced obesity and life expectancy less than 6 months. Research Instrument included: demographic, biopsy results, histological grades and Gleason score.

Results: Among 71 controls: 32 % had PSA level 0-3.9 ng/ml, 52% had PSA level 4-9.9 ng/ml and 16 % had PSA level 10 ng/ml and above. Among 158 prostate cancer cases: 9% had PSA level 0-3.9 ng/ml, 43% had PSA level 4-9.9 ng/ml and 48 % had PSA level 10 ng/ml and above. Gleason scores among cases were: 21% scores 4 and 5 and 79% scores 6 to 9.

Conclusions: Using 4ng/ml cutoff point, this study found: false negative 9% among cases and false positive 68% among biopsied controls. Further discussion of such dilemma will be presented.