About 80-95% of all cases of prostate cancer are carcinomas that develop in the glandular tissue of the prostate.Most cases of prostatic adenocarcinoma grow more slowly than most other types of cancer. In fact, some prostate tumors grow so slowly that they never require treatment.

Extracapsular extension refers to the point at which the prostate cancer cells have extended into, and possibly through, the prostate capsule (the outer lining of the prostate gland). The cancer cells may extend through parts of one or both lobes of the gland. Extracapsular extension does not mean the same thing as metastatic cancer.