PSA, or prostate specific antigen, is a protein secreted by normal prostate tissue glands, primarily into the ejaculate fluid, with a small amount measured in the blood. Any inflammatory process, acute injury, benign enlargement, or prostate cancer may elevate the PSA. After discussion of the risks and benefits of cancer screening, most primary care physicians usually draw the PSA with routine blood tests at the time of annual physical examinations, starting at age 50 for most men, or at age 40 for patients at higher risk. Higher risk patients include men with a family history of prostate cancer or African-Americans. This screening may improve survival if the tumor is found and treated early.