skip to main content

Possible prostate cancer in a man taking finasteride for benign prostatic enlargement — MSRA MCQ

Instant feedback + full explanation. One question, done properly.

HardUrologyPossible prostate cancer in a man taking finasteride for benign prostatic enlargementMSRA

A 68-year-old man attends for review of lower urinary tract symptoms due to benign prostatic enlargement. He has taken tamsulosin 400 micrograms daily and finasteride 5 mg daily for 9 months, with improvement in hesitancy and weak stream. He now reports persistent nocturia and erectile dysfunction. He has no dysuria, fever, perineal pain, visible haematuria, bone pain or weight loss. Urine culture is negative. Digital rectal examination shows a smooth, symmetrically enlarged prostate. Following discussion, a PSA test is 2.6 micrograms/L. He is fit, has no major comorbidity and would wish to undergo investigation if clinically indicated. What is the most appropriate next management step?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Discuss and arrange a suspected cancer pathway referral for prostate cancer

Explanation lettering: B = shown as A · A = shown as B · E = shown as C · C = shown as E

Finasteride reduces PSA concentrations. After at least 6 months of finasteride 5 mg treatment, the measured PSA should be doubled when comparing it with reference ranges for untreated men. This man's PSA of 2.6 micrograms/L therefore corresponds to approximately 5.2 micrograms/L. For a man aged 60 to 69 years with lower urinary tract symptoms or erectile dysfunction, this exceeds the NICE age-specific PSA threshold of 4.5 micrograms/L at which a suspected cancer pathway referral should be considered. His preference for investigation and lack of major comorbidity support proceeding with referral. A is inappropriate because interpreting the unadjusted PSA would falsely reassure. B is unnecessary: stopping finasteride is not required to interpret PSA, and would delay assessment. C is initially tempting because prostatitis can raise PSA, but there are no infective or inflammatory symptoms and urine culture is negative; empirical antibiotics are not justified. D under-prioritises the cancer risk: although he has known benign prostatic enlargement and a benign-feeling prostate, neither excludes prostate cancer. A normal DRE does not negate the appropriately adjusted PSA result.

Reference: Finasteride 5 mg film-coated tablets - Summary of Product Characteristics (2025) — https://www.medicines.org.uk/emc/product/13543/smpc Suspected cancer: recognition and referral (NG12), urological cancers: prostate cancer (2015; recommendation updated 2021) — https://www.nice.org.uk/guidance/ng12/chapter/Recommendations-organised-by-site-of-cancer