Prostate cancer: Does PSA level affect prognosis?

Prostate-specific antigen (PSA) is a protein made by prostate tissue. Men with prostate cancer often have elevated PSA levels because the cancer cells make excessive amounts of this protein.

At the time of initial diagnosis of prostate cancer, PSA level helps determine how likely it is that the cancer has spread (metastasized). It also determines how likely the cancer will be cured with treatment such as radiation or surgery. Generally, the higher the PSA level and the higher the speed at which it increases, the more prostate cancer cells you have in your body.

But this isn't always the case. A small percentage of prostate cancers don't lead to elevated PSA. In some cases, the PSA level may be normal or even low, despite the prostate cancer. These cancer cells often have more genetic mutations than other cancer cells do, and they don't have the ability to make PSA. This type of prostate cancer is usually more aggressive and doesn't respond well to treatment. Some scientists believe that genetic mutations in these cancer cells may allow such cancers to grow and spread more quickly.

Prostate cancer often grows very slowly. The reasons for this aren't clear. Some research suggests that PSA may inhibit the formation of new blood vessels (angiogenesis) that contribute to the growth of cancer. This could explain why prostate cancers that don't produce PSA tend to grow and spread more rapidly than prostate cancers that do produce PSA.

More research is needed to determine if these findings may affect the prognosis and treatment of prostate cancer in humans.