Primary Criteria for Choosing a Prostate Cancer Screening Test
The primary criterion for choosing a prostate cancer screening test is to detect clinically significant, high-grade cancers early enough to enable curative treatment while minimizing detection of indolent disease that would never threaten the patient's life—not simply detecting as many cases as possible. 1
The Fundamental Goal: Early Detection of Aggressive Disease Only
The correct answer is B: Detect early cancer stage—but with critical qualifications that distinguish effective screening from harmful overdetection:
The screening test must identify aggressive prostate cancer early enough to cure it before it spreads outside the prostate, while avoiding overdetection of indolent tumors. 1 This is the fundamental goal stated by the National Comprehensive Cancer Network.
Autopsy studies reveal that prostate cancer is present in 33% of men over age 50, yet most of these cancers would never become clinically apparent during the patient's lifetime. 1 This means detecting "as many cases as possible" (option A) would cause massive harm through overdiagnosis.
For every 1 prostate cancer death prevented, 37 additional men receive unnecessary cancer diagnoses with exposure to all treatment harms but no benefit. 2 This demonstrates why maximizing detection is the wrong goal.
Why Specificity Matters More Than Sensitivity
The question correctly identifies PSA's low specificity as a major problem:
PSA testing has poor specificity of only 60-70% at the conventional 4.0 ng/mL cutoff, producing frequent false-positive results. 1 These false positives lead to unnecessary biopsies, patient anxiety, and potential complications including drug-resistant infections.
A screening test must have adequate specificity to avoid false-positives that lead to unnecessary biopsies. 1 Two-thirds of men with elevated PSA have negative biopsies, with biopsy complications including blood in semen (93%), blood in urine (66%), pain (44%), fever (18%), and hospitalization for sepsis (1-2%). 3
Biomarker tests and multiparametric MRI can improve specificity and reduce unnecessary biopsies by 20-30%. 1
Why Cost and Availability Are Secondary Considerations
Option C (inexpensive and widely available) is mentioned in the question but is explicitly not the primary criterion:
While cost-effectiveness and wide availability are relevant factors, these are secondary to the test's ability to improve clinical outcomes without causing net harm. 1 The American Cancer Society clearly states this hierarchy.
The principal strengths of PSA include its reasonable cost and high patient acceptance, but these advantages are overshadowed by its imperfect specificity. 4
Why Screening Symptomatic Patients Is Wrong
Option D (done for patients with symptoms) fundamentally misunderstands screening:
Screening by definition targets asymptomatic individuals. 4 PSA was first used to monitor patients after treatment, then later applied to detecting early prostate cancer in men with no symptoms or signs of prostate disease.
If a patient has symptoms, diagnostic evaluation—not screening—is appropriate.
Essential Requirements for Effective Screening
Beyond early detection, the screening test must meet these criteria:
Men must have at least 10-15 year life expectancy to potentially benefit from screening, as this is the timeframe needed for early detection and treatment to impact outcomes. 1 Screening men over 75 years or those with <10 year life expectancy substantially increases overdetection without mortality benefit. 1
The test should enable risk stratification—men with PSA <1.0 ng/mL at age 60 have <0.3% likelihood of prostate cancer death, allowing less intense follow-up. 1
The test must be acceptable enough to allow shared decision-making and informed consent, as screening should never occur without patients understanding the benefits, risks, and uncertainties. 1 Two-thirds of US men reported no discussion with physicians about advantages, disadvantages, or scientific uncertainty regarding PSA screening—this represents inappropriate use. 1
Common Pitfalls to Avoid
Do not prioritize sensitivity alone, as a test that detects every cancer (including all indolent disease) causes massive overdiagnosis and overtreatment, with attendant complications including incontinence, impotence, and bowel dysfunction. 1
Avoid screening without counseling. 1 The European Association of Urology explicitly recommends against PSA testing without prior counseling on potential risks and benefits. 3
Do not screen men with limited life expectancy. 1 Screening men over 75 years substantially increases overdetection without providing mortality benefit.
The Evidence on PSA Screening Effectiveness
PSA screening prevents approximately 1-2 prostate cancer deaths per 1,000 men screened over 13 years in men aged 55-69 years. 2
The European ERSPC trial showed a 21% relative reduction in prostate cancer mortality, but this required screening 781 men and treating 27 patients to prevent one death. 2
Overdiagnosis affects 29-44% of all PSA-detected cancers, meaning these men receive cancer diagnoses that would never have caused symptoms or death. 2