skip to main content

Benign prostatic enlargement treated with finasteride; rising adjusted PSA suggesting possible prostate cancer

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

HardLUTSBenign prostatic enlargement treated with finasteride; rising adjusted PSA suggesting possible prostate cancerMSRA

A 68-year-old man is reviewed 12 months after starting tamsulosin MR 400 micrograms once daily and finasteride 5 mg once daily for bothersome voiding LUTS. Before treatment, his IPSS was 22, DRE showed a smooth prostate estimated at 46 g, and PSA was 3.0 micrograms/L. His urinary symptoms have improved and he reports good adherence. His PSA was 1.5 micrograms/L after 6 months of finasteride but is now 2.6 micrograms/L. He has not had a urinary tract infection, urinary retention, catheterisation, ejaculation or vigorous cycling in the preceding 48 hours. DRE remains smooth and he has no bone pain, weight loss or visible haematuria. What is the most appropriate next step?

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

Reveal the answer and explanation

Correct answer: E — Arrange a suspected cancer pathway referral for prostate cancer

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

Finasteride lowers serum PSA by approximately 50%; after at least 6 months, the measured PSA should therefore be doubled when comparing it with reference ranges in untreated men. This man's current PSA of 2.6 micrograms/L is equivalent to approximately 5.2 micrograms/L. He is aged 68 years, for whom the NICE age-specific referral threshold is greater than 4.5 micrograms/L. He also has LUTS, so this warrants consideration of a suspected cancer pathway referral. The serial rise is additionally concerning: his PSA had initially fallen appropriately to 1.5 micrograms/L but has subsequently increased despite reported adherence. The finasteride SmPC states that any sustained PSA increase during treatment should be carefully evaluated. There is no evident transient explanation for PSA elevation in the stem. A and E inappropriately delay assessment despite an adjusted PSA above the referral threshold. C is unnecessary: stopping finasteride does not clarify the immediate cancer risk and delays referral. D may appear reasonable because he is already receiving LUTS treatment, but routine referral does not reflect the suspected malignancy pathway indicated by the 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) — Recommendations organised by site of cancer (Updated 15 April 2026) — https://www.nice.org.uk/guidance/ng12/chapter/Recommendations-organised-by-site-of-cancer Lower urinary tract symptoms in men: management (CG97) — Recommendations (Last updated 3 June 2015) — https://www.nice.org.uk/guidance/cg97/chapter/recommendations