Screening — Risk-Targeted PSA Testing to Limit Overdiagnosis
A 47-year-old male public-health physician is revising a regional prostate cancer early-detection programme. An audit shows that many men with raised prostate-specific antigen had benign prostatic hyperplasia or indolent tumours, and several underwent biopsies and radical treatment with incontinence or erectile dysfunction. Which of the following strategies best addresses this problem while preserving the benefit of testing?
- A.Lower the PSA threshold so the greatest number of cancers is detected
- B.Offer testing selectively to men at increased risk, such as those with a family historyCorrect
- C.Offer annual PSA testing to all men from 40 years to find cancer at the earliest stage
- D.Restrict PSA testing to men who present with lower urinary tract symptoms
Explanation
The audit describes the consequence of low specificity: PSA rises in benign prostatic hyperplasia, prostatitis and after instrumentation, and unselected testing also detects slow-growing cancers that would never have caused harm, leading to overdiagnosis and overtreatment. Because population-wide PSA screening has only a small mortality benefit, current guidance moves away from blanket testing toward a risk-adapted approach. The European Association of Urology recommends offering early PSA testing, after informed discussion, to men at elevated risk, such as those with a first-degree relative affected, men of African descent from 45 years, and BRCA2 carriers from 40 years; the US Preventive Services Task Force supports individual shared decisions at 55 to 69 years. Selecting higher-risk men raises the pretest probability, so a positive result is more likely to be a true positive. Lowering the threshold or testing all men from 40 increases sensitivity at the cost of more false positives and more overtreatment. Testing only symptomatic men is diagnostic evaluation, not early detection, and urinary symptoms usually reflect benign enlargement. A frequently missed refinement is that MRI before biopsy further reduces unnecessary biopsies.
Why each option
- A.
- Lowering the threshold increases sensitivity but further reduces specificity, producing more false positives, biopsies and overtreatment of indolent disease.
- B.
- Correct. Targeting higher-risk men raises pretest probability and positive predictive value, reducing false positives and overtreatment while retaining benefit.
- C.
- Blanket annual testing from 40 years maximises detection of indolent tumours and is the pattern that drives overdiagnosis and treatment harms.
- D.
- Testing symptomatic men is diagnosis rather than screening, and urinary symptoms mostly reflect benign enlargement that itself raises PSA.
Reference: EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer 2024; US Preventive Services Task Force — Prostate Cancer Screening Recommendation 2018
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