Prostate-Specific Antigen (PSA) is a marker for which type of cancer?

Prostate-Specific Antigen (PSA) is a biomarker primarily used in the diagnosis and monitoring of prostate adenocarcinoma, which is a common type of cancer that arises from the glandular cells of the prostate. PSA is produced by both normal and malignant prostate tissue, but elevated levels are often associated with prostate cancer, making it an important tool for screening.

In clinical practice, measuring PSA levels can help detect prostate cancer in its early stages when treatment may be more effective. Elevated PSA levels can also indicate disease progression or recurrence after treatment. However, it's important to note that elevated PSA levels can occur in benign conditions such as benign prostatic hyperplasia (BPH) or prostatitis, which is why PSA is not exclusively indicative of cancer.

The other options do not have a direct association with PSA. Hepatocellular carcinoma is monitored using alpha-fetoprotein (AFP), while adult T-cell leukemia/lymphoma and CNS malignant lymphoma do not have specific serum markers like PSA for diagnostic purposes. Therefore, the direct link between elevated PSA levels and prostate adenocarcinoma highlights why this answer is correct.