In monitoring a patient with nonpalpable prostate cancer, which test is recommended to assess disease progression?

The recommended test to assess disease progression in a patient with nonpalpable prostate cancer is the measurement of prostate-specific antigen (PSA). PSA is a protein produced by both normal and malignant cells of the prostate gland. In the context of prostate cancer, levels of PSA in the blood can provide valuable information regarding the status of the disease.

Elevated PSA levels can indicate disease progression, recurrence, or response to treatment, making it a crucial tool for monitoring patients who do not have palpable lesions. Regular measurements of serum PSA allow clinicians to track changes over time and make informed decisions about further diagnostic evaluations or interventions.

Other tests mentioned, such as transrectal ultrasonography and periodic rectal exams, are used in the initial diagnosis and evaluation of prostate cancer, but they do not provide specific, quantitative data about tumor progression. Similarly, while measurements of serum acid phosphatase were historically used for assessing advanced prostate cancer, their role has diminished in favor of PSA testing, which has a more established correlation with disease status.