What are the Prostate-Specific Antigen (PSA) levels?

From the Guidelines

PSA levels should be considered in the context of overall prostate health, with normal levels generally below 4 ng/mL, and screening recommended for men starting at age 50, or earlier for those with risk factors, as outlined in the American Cancer Society guideline update 2010 1. When evaluating PSA levels, it's essential to consider the individual's age, risk factors, and overall health.

• For men in their 40s, levels below 2.5 ng/mL are typically expected, while men in their 50s might have slightly higher baseline levels.
• PSA testing is recommended for men starting at age 50, or earlier (around 45) for those with risk factors such as family history or African American ethnicity.
• The test should be performed annually or biannually depending on previous results and risk factors.
• Elevated PSA levels don't always indicate cancer, as conditions like prostatitis, benign prostatic hyperplasia (BPH), or recent ejaculation can temporarily raise PSA levels.
• If elevated levels are found, your doctor may recommend additional testing such as a prostate biopsy, MRI, or repeat PSA testing after a few weeks.
• PSA velocity (how quickly levels rise over time) is often more informative than a single elevated reading, as noted in the American Cancer Society guideline update 2010 1. Before having a PSA test, it's crucial to:
• Avoid ejaculation for 48 hours
• Avoid prostate manipulation like cycling or digital rectal exams
• Inform your doctor about any medications that might affect results, such as finasteride or dutasteride, which can artificially lower PSA readings, as discussed in the context of prostate cancer treatment options 1.

From the FDA Drug Label

1. 1 Effects on Prostate Specific Antigen (PSA) and the Use of PSA in Prostate Cancer Detection In clinical studies, finasteride tablets reduced serum PSA concentration by approximately 50% within six months of treatment. To interpret an isolated PSA value in patients treated with finasteride tablets for six months or more, PSA values should be doubled for comparison with normal ranges in untreated men. The ratio of free to total PSA (percent free PSA) remains constant even under the influence of finasteride tablets. Prostate-Specific Antigen (PSA) Test: Your healthcare provider may check you for other prostate problems, including prostate cancer, before you start and while you take dutasteride capsules. A blood test called PSA (prostate-specific antigen) is sometimes used to see if you might have prostate cancer. Dutasteride capsules will reduce the amount of PSA measured in your blood

PSA Levels: Finasteride and dutasteride reduce serum PSA concentration by approximately 50% within six months of treatment 2. To interpret PSA values, they should be doubled for comparison with normal ranges in untreated men 2.

• Key Points:
  • Finasteride and dutasteride decrease PSA levels by 50% within 6 months of treatment.
  • PSA values should be doubled for comparison with normal ranges in untreated men.
  • The ratio of free to total PSA remains constant under the influence of finasteride.
  • Increases in PSA levels while on treatment should be evaluated by a healthcare provider 3.

From the Research

PSA Levels and Prostate Cancer Detection

• PSA levels are used as a screening test for prostate cancer, with higher levels indicating a higher risk of cancer 4, 5
• The combination of digital rectal examination (DRE) and PSA testing provides a more complete evaluation of the prostate gland for malignant involvement 4
• Studies have shown that PSA levels are as effective as or more effective than DRE for the detection of prostate cancer 4, 6

Factors Associated with PSA Levels and Prostate Cancer Risk

• High PSA values and a rising PSA are associated with an increased risk of prostate cancer 5
• Family history of prostate cancer, abnormal DRE result, African American race, and older age are also associated with an increased risk of prostate cancer 5
• A prior negative biopsy is associated with decreased risk of prostate cancer and high-grade prostate cancer 5

Role of Digital Rectal Examination in Prostate Cancer Detection

• DRE is routinely performed as part of a urology clinical assessment in patients with a clinical suspicion of prostate cancer 7
• However, the diagnostic value of DRE is limited, and it may not be necessary to conduct this examination routinely in the absence of clinical symptoms and signs 6
• Finasteride has been shown to improve the sensitivity of DRE for prostate cancer detection 8

Comparison of PSA and DRE for Prostate Cancer Screening

• A meta-analysis found that the positive predictive value (PPV) of DRE was similar to that of PSA, but the cancer detection rate (CDR) of DRE was significantly lower than that of PSA 6
• The combination of DRE and PSA did not provide a significant benefit over PSA alone in terms of CDR and PPV 6