What is the guidance for Prostate-Specific Antigen (PSA) testing and management of prostate cancer?

PSA Testing and Prostate Cancer Management Guidance

For most men, PSA screening should not be routinely performed as the harms outweigh the benefits, but shared decision-making should be used for men aged 55-69 who express interest after being fully informed of risks and benefits. 1, 2

Screening Recommendations by Age and Risk Group

Who Should Consider Screening

• Average-risk men: May consider screening at age 50 after shared decision-making
• High-risk men (African Americans, first-degree relative with prostate cancer before age 65): May consider screening at age 45
• Very high-risk men (multiple first-degree relatives diagnosed before age 65): May consider screening at age 40 1

Screening Intervals Based on PSA Levels

• PSA < 1.0 ng/mL: Rescreen every 2-4 years
• PSA 1.0-2.5 ng/mL: Rescreen every 2 years
• PSA ≥ 2.5 ng/mL: Rescreen annually 1

When to Stop Screening

• Men over age 69-70 years
• Men with life expectancy less than 10-15 years, regardless of age 1

Benefits vs. Harms of PSA Screening

Benefits

• May prevent approximately 1.3 deaths from prostate cancer per 1000 men screened over 13 years
• May prevent approximately 3 cases of metastatic prostate cancer per 1000 men screened 1, 3

Harms

• False positive results leading to unnecessary anxiety and procedures
• Overdiagnosis of clinically insignificant cancers
• Complications from prostate biopsy (infection, bleeding)
• Treatment complications:
  • Radical prostatectomy: 11% increased risk of urinary incontinence and 37% increased risk of erectile dysfunction 2
  • Radiation: Bowel symptoms, urinary and sexual dysfunction 3

Interpreting PSA Results

Important Considerations

• A single elevated PSA should not prompt immediate biopsy and should be verified by a second test 1
• PSA levels can be affected by:
  • Medications like finasteride and dutasteride (reduce PSA by approximately 50%) 4, 5
  • Recent ejaculation or vigorous exercise (can cause false elevations) 1

For Men on 5α-Reductase Inhibitors

• Establish a new PSA baseline at least 3-6 months after starting treatment
• Double the PSA value for comparison with normal ranges in untreated men
• Any confirmed increase from the lowest PSA value may signal prostate cancer and should be evaluated 4, 5
• Free-to-total PSA ratio remains constant under the influence of these medications 4, 5

Shared Decision-Making Process

When discussing PSA screening with patients, cover these key points:

1. PSA screening is controversial
2. For most men, the chances of harm outweigh the chances of benefit
3. Most prostate cancer is slow-growing and doesn't cause death
4. Men who decline PSA testing will likely die from other causes
5. Men who choose PSA testing are more likely to be diagnosed with prostate cancer
6. PSA test often doesn't distinguish between serious and non-serious cancer
7. PSA testing may lead to a cascade of additional tests and treatments with significant side effects 2

Risk of High-Grade Prostate Cancer with 5α-Reductase Inhibitors

Men taking finasteride or dutasteride should be informed of an increased risk of high-grade prostate cancer:

• Finasteride: 1.8% vs. 1.1% in placebo group
• Dutasteride: 1% vs. 0.5% in placebo group 4, 5

Common Pitfalls to Avoid

1. Treating PSA as "just a blood test": It's a test that can lead to a cascade of interventions with potential harms 2
2. Immediate biopsy after a single elevated PSA: Verify with a second test 1
3. Not adjusting PSA interpretation for men on 5α-reductase inhibitors: PSA values should be doubled 4, 5
4. Continuing screening in elderly men or those with limited life expectancy: The harms clearly outweigh benefits in men over 70 1, 3
5. Aggressive treatment for low-risk disease: Active surveillance should be considered for low-risk tumors to maximize quality-adjusted life years 6

By following these evidence-based recommendations and engaging in thorough shared decision-making, clinicians can help patients make informed choices about PSA screening that align with their values and preferences.