What does PSA primarily indicate once prostate adenocarcinoma has been established?

PSA, or prostate-specific antigen, is a protein produced by both normal and malignant cells of the prostate gland. Once prostate adenocarcinoma has already been established, the level of PSA in the blood primarily reflects the tumor burden. This means that higher levels of PSA can indicate a larger tumor size or a greater extent of disease, while lower levels may suggest a smaller tumor or less extensive disease.

Monitoring PSA levels is crucial for patients with diagnosed prostate cancer because it helps in assessing the effectiveness of treatment, detecting recurrence, and determining the overall prognosis. It’s especially significant in the context of therapy; as treatment takes effect, one would generally expect PSA levels to decrease. Conversely, if PSA levels begin to rise again after treatment, this may suggest disease progression or recurrence.

While PSA can also be associated with other conditions (such as benign prostatic hyperplasia or prostatitis), its primary utility after a diagnosis of prostate cancer is in monitoring tumor activity and burden, making it a vital tool in the management of prostate cancer patients.