Which of the following is useful in the detection and management of carcinoma of the prostate?

• A. Total prostate-specific antigen
• B. Prostatic acid phosphatase
• C. Human chorionic gonadotropin
• D. Alpha-fetoprotein

Answer: (A)

Total PSA is the most useful blood marker for both detecting and monitoring prostate cancer because it is produced by the prostate and leaks into the blood more when malignancy is present. In screening, a higher PSA level can prompt further evaluation with imaging and biopsy, though it must be interpreted alongside age, prostate size, and other factors since benign conditions can also raise PSA. In management, PSA serves as a monitoring tool: after surgery, PSA should be undetectable, and any rise suggests residual disease or recurrence; the rate of rise (PSA velocity) and how quickly it doubles provide prognostic clues and help guide further treatment decisions. Prostatic acid phosphatase was used in the past but is much less sensitive and specific than PSA, so its role in detection and management has diminished. The other markers, human chorionic gonadotropin and alpha-fetoprotein, are associated with germ cell tumors and liver cancers, not prostate cancer, so they aren’t useful for detecting or managing it.