11.   That test, the PSA, for prostate specific antigen, can lead to the detection of tiny tumors.

12.   The blood test measures a protein known as PSA, for prostate specific antigen.

13.   The men received digital rectal exams and blood tests for prostate specific antigen, a protein that, when found at elevated levels, may indicate prostate cancer.

14.   The recommendation does not include men with moderate or high levels of PSA, or prostate specific antigen, an antibody the body produces to combat cancer.

15.   Therion and others are developing vaccines against specific antigens, usually proteins the body regards as foreign and potentially dangerous, for large populations of cancer patients.

16.   When they analyzed the results, researchers found that men with higher stress levels were three times as likely to have high levels of prostate specific antigen.

17.   The blockers are sometimes used before surgery or radiation to shrink the prostate and reduce prostate specific antigen, or PSA, levels.

18.   Monoclonal antibodies are genetically engineered proteins designed to target specific antigens on the surface of the tumor cells.