When to repeat Prostate-Specific Antigen (PSA) test?

From the Guidelines

The timing for repeating a PSA test should be individualized based on your baseline PSA level and risk factors, with the most recent guidelines suggesting testing every 1-2 years for men with normal PSA levels and no risk factors, starting at age 50. For men with normal PSA levels (generally under 4 ng/mL) and no risk factors, testing every 1-2 years is typically recommended starting at age 50 (or age 45 for high-risk individuals, including African American men and those with family history) 1. If your PSA is elevated but below 10 ng/mL, retesting in 1-3 months is often suggested to confirm results before making treatment decisions. For PSA levels above 10 ng/mL, prompt follow-up with a urologist is recommended. After prostate cancer treatment, PSA monitoring is more frequent—typically every 3-6 months for the first 5 years, then annually thereafter 1. Some key points to consider when deciding on the frequency of PSA testing include:

• PSA levels naturally increase with age
• Temporary elevations can occur due to factors like recent ejaculation, prostatitis, urinary tract infections, or prostate manipulation (including digital rectal exams and biopsies) 1. PSA testing helps detect prostate cancer early when treatment is most effective, but the interpretation of results should always be done in consultation with your healthcare provider who can consider your complete clinical picture 1. It is essential to weigh the benefits of early detection against the potential harms of overdiagnosis and overtreatment, and to make informed decisions based on individual risk factors and medical history. In terms of specific guidelines for repeating PSA tests, the American Cancer Society recommends against routinely incorporating PSA velocity into prostate cancer screening strategies, as it has not been shown to provide independent predictive information beyond that provided by PSA alone 1. Instead, the focus should be on individualized risk assessment and shared decision-making between patients and healthcare providers. Ultimately, the decision on when to repeat a PSA test should be based on a thorough discussion of the potential benefits and harms, as well as consideration of individual patient preferences and values.

From the FDA Drug Label

In clinical studies, finasteride tablets reduced serum PSA concentration by approximately 50% within six months of treatment. This decrease is predictable over the entire range of PSA values in patients with symptomatic BPH, although it may vary in individuals For interpretation of serial PSAs in men taking finasteride tablets, a new PSA baseline should be established at least six months after starting treatment and PSA monitored periodically thereafter Any confirmed increase from the lowest PSA value while on finasteride tablets may signal the presence of prostate cancer and should be evaluated, even if PSA levels are still within the normal range for men not taking a 5α-reductase inhibitor.

When to Repeat PSA Test:

• A new PSA baseline should be established at least six months after starting finasteride treatment.
• PSA should be monitored periodically thereafter.
• Any confirmed increase from the lowest PSA value while on finasteride may signal the presence of prostate cancer and should be evaluated 2.

In clinical trials, dutasteride reduced serum PSA concentration by approximately 50% within 3 to 6 months of treatment. This decrease was predictable over the entire range of PSA values in subjects with symptomatic BPH, although it may vary in individuals To interpret serial PSAs in men taking dutasteride, a new PSA baseline should be established at least 3 months after starting treatment and PSA monitored periodically thereafter

When to Repeat PSA Test:

• A new PSA baseline should be established at least 3 months after starting dutasteride treatment.
• PSA should be monitored periodically thereafter.
• Any confirmed increase from the lowest PSA value while on dutasteride may signal the presence of prostate cancer and should be evaluated 3.

From the Research

When to Repeat Prostate-Specific Antigen (PSA) Test

• The decision to repeat a PSA test depends on various factors, including the initial PSA level, age, and medical history 4.
• A study found that men with an initial PSA level of ≥10ng/ml should prompt further investigation, but approximately one out of 10 men did not receive repeat testing within 1 year of the initial test 4.
• Another study suggested that a 20% decrease in PSA values is associated with a reduced risk of cancer and particularly of high-grade cancer 5.
• However, short-term decreases in PSA may occur in men with prostate cancer, including high-grade cancer, and should not influence the decision to proceed to prostate biopsy 6.

Factors Influencing Repeat PSA Testing

• Age: Men aged 50-69 years with a PSA level of >10ng/ml should prompt further investigation 4.
• Medical history: Comorbidities did not significantly affect the follow-up of men with elevated PSA levels 4.
• Finasteride use: Finasteride decreases serum PSA by approximately 50%, and patients without prostate cancer have a greater decrease in PSA density (PSAD) when taking finasteride than those with prostate cancer 7, 8.

PSA Level Changes and Prostate Cancer Risk

• A decrease in PSA level of ≥20% is associated with a lower risk of prostate cancer and high-grade disease 5.
• A stable PSA level within a 20% variation is associated with a higher risk of prostate cancer and high-grade disease 5.
• An increase in PSA level of ≥10% is associated with an increased risk of high-grade prostate cancer 5.