NCIt definition : A clinically undetectable tumor confined to the prostate gland, normally an incidental
finding during surgery.;
Alternative definition : NCI-GLOSS: A prostate cancer stage defined by the Jewett staging system. Stage A prostate
cancer is cancer that began in the prostate and is found in the prostate only. It
is usually found during surgery for other reasons, such as benign prostatic hyperplasia
(a condition in which an overgrowth of prostate tissue occurs). Stage A is divided
into stages A1 and A2. In stage A1, the cancer cells do not look very different from
normal cells. In stage A2, the cancer cells look more abnormal or are in several areas
in the prostate.;