What is the next step for a 58-year-old asymptomatic man with a significantly elevated Prostate-Specific Antigen (PSA) level, from 2.4 ng/mL to 28 ng/mL, who is taking finasteride (1 mg daily) for hair loss prevention and has a normal Digital Rectal Examination (DRE)?

From the Guidelines

The next step for this 58-year-old asymptomatic man with a significant PSA elevation from 2.4 to 28 ng/mL while on finasteride should be immediate discontinuation of finasteride followed by repeat PSA testing in 4 months. This approach is based on the understanding that finasteride can lower PSA levels, and a significant increase despite its use warrants further investigation 1. The dramatic rise in PSA is concerning and necessitates thorough evaluation, considering the potential for prostate cancer. After discontinuing finasteride and allowing for a washout period, if the PSA remains significantly elevated, the patient should undergo a prostate biopsy to evaluate for prostate cancer, as the normal digital rectal exam does not rule out significant disease 1. It's crucial to consider the patient's age, the significant increase in PSA, and the potential for false-negative or false-positive test results when deciding on the next steps 1. Key points to consider include:

• The effect of finasteride on PSA levels and the need for a washout period before retesting
• The significance of a dramatic PSA increase despite finasteride use
• The importance of prostate biopsy in evaluating significantly elevated PSA levels
• The role of patient counseling regarding the possibility of prostate cancer and the need for prompt follow-up.

From the FDA Drug Label

In clinical studies, finasteride tablets reduced serum PSA concentration by approximately 50% within six months of treatment. 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 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 next step is to stop finasteride and repeat PSA in four months or to interpret the PSA value by doubling it, but since the patient's PSA level increased from 2.4 ng/mL to 28 ng/mL, which is a significant increase, and considering the patient has been taking finasteride, the most appropriate step would be to stop finasteride and repeat PSA in four months to accurately assess the patient's PSA level without the influence of finasteride. 2

From the Research

Next Steps for Elevated PSA Levels

The patient in question has a significantly elevated Prostate-Specific Antigen (PSA) level, from 2.4 ng/mL to 28 ng/mL, while taking finasteride (1 mg daily) for hair loss prevention and having a normal Digital Rectal Examination (DRE). Considering the effects of finasteride on PSA levels, the next steps should be based on the understanding that finasteride can decrease serum PSA by approximately 50% 3, 4.

Consideration of Finasteride's Effect on PSA

• Finasteride decreases PSA levels, which can affect the interpretation of PSA results 3, 4.
• The reduction in PSA levels due to finasteride should be considered when evaluating the risk of prostate cancer 5, 6.
• Studies suggest that the magnitude of PSA reduction after finasteride administration can be useful in diagnosing prostate cancer in men with previous negative biopsies 7.

Appropriate Action

Given the information and the context of finasteride's effect on PSA levels:

• The most appropriate next step would be to stop finasteride and repeat PSA in four months. This approach allows for the assessment of the patient's PSA level without the confounding effect of finasteride, providing a more accurate basis for further decision-making 4, 7.
• Other options, such as immediately recommending a prostate biopsy or repeating the PSA without considering the finasteride effect, may not be the best initial steps given the potential for finasteride to alter PSA levels significantly.

Rationale

• Stopping finasteride is crucial because it allows for an accurate measurement of the patient's baseline PSA level without the influence of the medication.
• Repeating the PSA in four months after stopping finasteride provides a more reliable indicator of the patient's prostate health, helping to determine if the elevated PSA level was significantly influenced by finasteride or if there are other underlying issues that need to be addressed.