When prostate cancer spreads, it’s often found in nearby lymph nodes. If cancer has reached these nodes, it also may have spread to other lymph nodes, the bones, or other organs.
When cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if prostate cancer spreads to bones, the cancer cells in the bones are actually prostate cancer cells. The disease is metastatic prostate cancer, not bone cancer. For that reason, it’s treated as prostate cancer, not bone cancer. Doctors call the new tumor “distant” or metastatic disease.
These are the stages of prostate cancer:
- Stage I: The cancer can’t be felt during a digital rectal exam, and it can’t be seen on a sonogram. It’s found by chance when surgery is done for another reason, usually for BPH. The cancer is only in the prostate. The grade is G1, or the Gleason score is no higher than 4.
- Stage II: The tumor is more advanced or a higher grade than Stage I, but the tumor doesn’t extend beyond the prostate. It may be felt during a digital rectal exam, or it may be seen on a sonogram.
- Stage IIA: The tumor cannot be felt and involves half of 1 side of the prostate or even less than that. PSA levels are medium, and the cancer cells are well differentiated. This stage also includes larger tumors found only in the prostate, as long as the cancer cells are still well differentiated.
- Stage IIB: The tumor is found only inside the prostate, and it may be large enough to be felt during DRE. The PSA level is medium. The cancer cells are moderately differentiated.
- Stage IIC: The tumor is found only inside the prostate, and it may be large enough to be felt during DRE. The PSA level is medium. The cancer cells may be moderately or poorly differentiated.
- Stage III: The tumor extends beyond the prostate. The tumor may have invaded the seminal vesicles, but cancer cells haven’t spread to the lymph nodes.
- Stage IIIA: The cancer has spread beyond the outer layer of the prostate into nearby tissues. It may also have spread to the seminal vesicles. The PSA level is high.
- Stage IIIB: The tumor has grown outside of the prostate gland and may have invaded nearby structures, such as the bladder or rectum.
- Stage IIIC: The cancer cells across the tumor are poorly differentiated, meaning they look very different from healthy cells.
- Stage IV: The tumor may have invaded the bladder, rectum, or nearby structures (beyond the seminal vesicles). It may have spread to the lymph nodes, bones, or to other parts of the body.
- Stage IVA: The cancer has spread to the regional lymph nodes.
- Stage IVB: The cancer has spread to distant lymph nodes, other parts of the body, or to the bones.