Should I check my Prostate Specific Antigen (PSA) level?

Should You Check a PSA?

PSA screening should be offered through shared decision-making to men aged 50-69 with at least 10 years life expectancy, starting earlier at age 45 for African American men or those with a first-degree relative with prostate cancer, and as early as age 40 for men with multiple affected first-degree relatives diagnosed before age 65. 1

Key Principles for PSA Screening Decisions

Shared Decision-Making is Essential

• You must discuss both benefits and harms with patients before ordering PSA testing 1
• The primary benefit is potential reduction in prostate cancer-specific mortality, though all-cause mortality reduction has not been demonstrated 2
• Harms include false-positives, unnecessary biopsies, overdiagnosis of indolent cancers, and overtreatment complications 1
• The goal is identifying aggressive prostate cancer early enough to cure it, while avoiding detection and treatment of indolent disease that poses no threat 1

Age-Based Screening Recommendations

Average-Risk Men:

• Consider baseline PSA at age 40 to establish risk stratification 1
• If baseline PSA <1.0 ng/mL at age 40, rescreen at age 45 1
• If baseline PSA ≥1.0 ng/mL at age 40, annual follow-up is recommended 1
• Regular screening should begin at age 50 for all average-risk men 1
• Men aged 60 with PSA <1.0 ng/mL have very low risk of metastases or death from prostate cancer 1

High-Risk Men:

• African American men should begin screening at age 45 1
• Men with one first-degree relative diagnosed with prostate cancer (especially before age 65) should begin at age 45 1
• Men with multiple first-degree relatives with prostate cancer diagnosed before age 65 should begin at age 40 1

Older Men:

• Screening decisions should be individualized for men over age 75 based on health status and life expectancy 1
• Men aged 75-80 with PSA <3.0 ng/mL have very low risk of prostate cancer death 1
• Men with life expectancy <10 years are unlikely to benefit from screening 1

Screening Intervals

• Screening every 2-4 years is appropriate for most men aged 55-69 2
• Rescreening intervals should be risk-stratified based on baseline PSA values 1
• Men with PSA <1.0 ng/mL can have longer intervals between tests 1
• Men with elevated PSA values require more frequent monitoring 1

Critical Context About PSA Testing

Understanding PSA as a Predictor

• Baseline PSA at or before age 50 is a stronger predictor of future aggressive prostate cancer than family history or race 1, 3
• PSA above the median for age group (0.6-0.7 ng/mL for men in their 40s) indicates higher lifetime risk 1
• 90% of prostate cancer deaths occur in men in the top 10% for PSA values 1
• Two-thirds of advanced cancer cases occur in men with PSA ≥0.9 ng/mL at or before age 50 3

PSA Thresholds and Cancer Risk

• PSA >10 ng/mL confers >67% likelihood of prostate cancer and warrants biopsy regardless of other factors 1
• PSA 4-10 ng/mL: approximately 30-35% will have cancer on biopsy 1
• PSA 2.6-4.0 ng/mL: approximately 25-30% will have cancer 4
• Even PSA ≤4.0 ng/mL: 15% may have prostate cancer 1, 4

Complementary Testing

• PSA testing is not a substitute for digital rectal examination (DRE) - both together increase sensitivity over either alone 1
• Consider biomarkers (PHI, 4Kscore, PCA3, SelectMDx) and multiparametric MRI before biopsy to improve specificity and reduce unnecessary biopsies 1
• These adjunctive tests can avoid biopsy in 20-30% of patients 1

Common Pitfalls to Avoid

• Never order PSA without discussing risks and benefits first - this violates the shared decision-making principle endorsed by all major guidelines 1
• Don't interpret PSA in isolation - consider age, race, family history, DRE findings, and prior PSA values 1
• Don't assume all detected cancers require treatment - most low-risk cancers can be safely managed with active surveillance 1, 2
• Don't screen men with <10 years life expectancy or significant comorbidities - they won't benefit 1
• Don't forget that PSA can be elevated by benign prostatic hyperplasia, prostatitis, and recent instrumentation - educate patients about this distinction 1