Prostate Cancer Treatment (PDQ®): Treatment - Patient Information [NCI] - Stages of Prostate Cancer
The stage of the cancer is based on the results of the staging and diagnostic tests, including the prostate-specific antigen (PSA) test and the Gleason score. The tissue samples removed during the biopsy are used to find out the Gleason score. The Gleason score ranges from 2-10 and describes how different the cancer cells look from normal cells and how likely it is that the tumor will spread. The lower the number, the less likely the tumor is to spread.
There are three ways that cancer spreads in the body.
The three ways that cancer spreads in the body are:
- Through tissue. Cancer invades the surrounding normal tissue.
- Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
- Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
The following stages are used for prostate cancer:
As prostate cancer progresses from Stage I to Stage IV, the cancer cells grow within the prostate, through the outer layer of the prostate into nearby tissue, and then to lymph nodes or other parts of the body.
In stage I, cancer is found in the prostate only. The cancer:
- is found by needle biopsy (done for a high PSA level) or in a small amount of tissue during surgery for other reasons (such as benign prostatic hyperplasia). The PSA level is lower than 10 and the Gleason score is 6 or lower; or
- is found in one-half or less of one lobe of the prostate. The PSA level is lower than 10 and the Gleason score is 6 or lower; or
- cannot be felt during a digital rectal exam and cannot be seen in imaging tests. Cancer is found in one-half or less of one lobe of the prostate. The PSA level and the Gleason score are not known.