A serum PSA is used for all of the following except which?

A serum PSA is used for all of the following except which?

• A. Diagnosis
• B. Screening
• C. Monitoring response
• D. Detecting recurrence

Answer: (A)

The key idea is that PSA serves as a marker to flag risk and to watch disease over time, not to diagnose cancer on its own. In screening, a PSA test helps identify men who may need further evaluation. For monitoring, PSA levels after treatment should drop to very low or undetectable levels, and if they rise, it suggests the cancer may not be controlled. For detecting recurrence, a rising PSA after initial therapy alerts clinicians to recurrent disease, often before symptoms appear. The reason PSA isn’t used to diagnose is that elevated PSA isn’t specific to cancer—benign conditions like benign prostatic hyperplasia or prostatitis, along with recent ejaculation or instrumentation, can raise PSA. A biopsy is required to confirm cancer. So the use that doesn’t fit is diagnosis.

The key idea is that PSA serves as a marker to flag risk and to watch disease over time, not to diagnose cancer on its own. In screening, a PSA test helps identify men who may need further evaluation. For monitoring, PSA levels after treatment should drop to very low or undetectable levels, and if they rise, it suggests the cancer may not be controlled. For detecting recurrence, a rising PSA after initial therapy alerts clinicians to recurrent disease, often before symptoms appear. The reason PSA isn’t used to diagnose is that elevated PSA isn’t specific to cancer—benign conditions like benign prostatic hyperplasia or prostatitis, along with recent ejaculation or instrumentation, can raise PSA. A biopsy is required to confirm cancer. So the use that doesn’t fit is diagnosis.