Stage A. This is prostate cancer in its earliest stage. Typically, prostate cancer in this stage causes no symptoms. It is located entirely within the prostate gland, but is too small to be detected by a digital rectal exam (DRE). In many cases, Stage A prostate cancer is uncovered by diagnosing and treating another prostate-related problem, such as a benign (noncancerous) tumor, or during a follow-up for an abnormal PSA blood test.