Primary Criteria for Choosing a Screening Test for Prostate Cancer
The answer is B: Detect early cancer stage. The fundamental criterion for selecting a prostate cancer screening test is its ability to identify 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 1.
Why Early Detection of Aggressive Disease is the Primary Criterion
The National Comprehensive Cancer Network explicitly states that the fundamental goal of prostate cancer screening is to identify aggressive prostate cancer early and cure it before it spreads outside the prostate, while avoiding overdetection of indolent tumors 1. This criterion supersedes all others because:
Autopsy studies reveal that prostate cancer is present in 33% of men over age 50, yet most 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 and overtreatment.
Men must have at least 10-15 years of life expectancy to potentially benefit from screening, as this is the timeframe needed for early detection and treatment to impact outcomes 1, 2, 3. Without this window, early detection provides no mortality benefit.
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.
Why the Other Options Are Insufficient Primary Criteria
Option A (Detect as Many Cases as Possible) is Explicitly Wrong
Prioritizing sensitivity alone causes massive overdiagnosis and overtreatment with attendant complications including incontinence, impotence, and bowel dysfunction 1. The evidence demonstrates:
Overdiagnosis affects 29-44% of all PSA-detected cancers, meaning these men receive cancer diagnoses that would never have caused symptoms or death 2.
For every 1 prostate cancer death prevented, 37 additional men receive unnecessary cancer diagnoses with exposure to all treatment harms but no benefit 2.
Option C (Inexpensive and Widely Available) is Secondary
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 principal strengths of PSA include reasonable cost and high patient acceptance 4, but these practical considerations cannot override the fundamental requirement that screening must provide net clinical benefit.
Option D (Done for Patients with Symptoms) Describes Diagnostic Testing, Not Screening
Screening by definition is performed in asymptomatic individuals 4. PSA was first used to monitor patients after treatment, but strong evidence of its value in detecting early prostate cancer in men with no symptoms or signs of prostate disease was reported beginning in 1989 4. Testing symptomatic patients is diagnostic evaluation, not screening.
The Critical Balance: Specificity Matters as Much as Early Detection
A screening test must have adequate specificity to avoid false-positives that lead to unnecessary biopsies, patient anxiety, and potential complications including drug-resistant infections 1. This is why:
PSA testing has poor specificity (only 60-70% at the conventional 4.0 ng/mL cutoff), often producing false-positive results 1.
Two-thirds of men with elevated PSA have negative biopsies (false positives), 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.
Common Pitfalls to Avoid
Never screen without counseling: Two-thirds of US men reported no discussion with physicians about advantages, disadvantages, or scientific uncertainty regarding PSA screening—this represents inappropriate use 1, 3.
Never screen men with limited life expectancy: Screening men over 75 years or those with <10 year life expectancy substantially increases overdetection without mortality benefit 1, 3.
Never prioritize detection numbers over clinical significance: The stage distribution of screening-detected cancers must be more favorable than unscreened populations, with 91.7% of cancers detected being localized to the prostate after five years of annual testing 4.