Prostate cancer is cancer of the prostate, the gland found underneath the bladder in men that helps make seminal fluid. Once cancer is diagnosed, staging is done to describe the spread and extent of the cancer. Staging is also a standardized way to help guide treatment and prognosis. The staging process uses the Gleason score, which describes how the cancer cells look compared to healthy cells, the spread of disease, and the prostate-specific antigen (PSA) level. For prostate cancer, the stages run from stage I to stage IV, in order of ascending severity.
Stage III
The National Cancer Institute describes stage III prostate cancer as starting to spread past the prostate gland, and possibly invading the seminal vesicles. The lymph nodes and distant organs are cancer free, and the cancer has a Gleason score that can be anywhere from two to ten, and any PSA value. This stage may also be called stage C prostate cancer.
Stage IV
There are various diagnostic situations of which stage IV prostate cancer can consist. According to the National Cancer Institute, stage IV prostate cancer can also be called stage D1, or stage D2, prostate cancer. The first possible diagnostic scenario is that the cancer has spread past the prostate and seminal vesicles into other tissues near the prostate like the rectum or pelvic wall. The lymph nodes are still cancer free, as are distant organs, and the Gleason score and PSA numbers can be any value.
Stage IV
The next possible stage IV prostate cancer diagnosis can consist of the cancer invading surrounding tissues of the prostate and into the lymph nodes, according to the American Cancer Society. The cancer is still not in any distant organs, and the Gleason score and PSA can be any value.
Stage IV
The last diagnostic situation that can be classified as stage IV prostate cancer is when the cancer may be spreading into tissues around the prostate, and possibly into the lymph nodes. Cancer is found in distant organs of the body, and the Gleason score and PSA can be any values.
