PSA (prostate-specific antigen) blood test. A normal PSA is less than 4.0 ng/mL. If the PSA level is greater, it is more likely that prostate cancer is present. However, there are other conditions that can raise the PSA. Men with a PSA level between 4.0 and 10.0 ng/mL have about a 25 percent chance of having prostate cancer. If the PSA level is greater than 10.0ng/mL, the chance of having prostate cancer is over 50 percent. If you have a high PSA, a doctor will look at other factors such as age, race, and family history, and also rule out any other possible conditions causing the elevated PSA. If other conditions have been ruled out, the doctor will recommend a prostate biopsy.