Staging describes how far the cancer has spread from where it began. At stage 1, it is still inside the prostate. At stage 4, it has spread to distant parts of the body. This is called metastatic prostate cancer.
The stage is established at the time of diagnosis and stays the same no matter how the cancer behaves in the future. If your cancer is stage III when you receive your diagnosis, it will always be stage III, whether it shrinks, grows or spreads, or returns after treatment. This makes it easier for researchers to track the survival rates of patients with different stages of cancer.
Here’s what specific stages mean:
Stage 1 Prostate Cancer: The cancer cannot be found during a digital rectal exam. It is found as a result of prostate biopsies for a high or rising PSA, or discovered by chance when surgery is done for another reason, usually for lower urinary tract symptoms.
Stage 2 Prostate Cancer: The cancer can be felt during a prostate exam, but it has not spread outside the prostate.
Stage 3 Prostate Cancer: The cancer has spread outside the prostate. It may be in the tissues near the prostate, or it may have invaded the tissues around the prostate or seminal vesicles. It has not spread to the lymph nodes.
Stage 4 Prostate Cancer: This stage is called metastatic cancer, because it has metastasized, or spread, to distant parts of the body. The cancer may be in nearby pelvic muscles or organs (beyond the seminal vesicles). It may have spread to the lymph nodes. It may have spread to other parts of the body.
Accurate staging provides your medical team with information that will be very important for creating the best treatment plan for you.
T, N, M Stages
The TNM System is a more specific way of describing how far the cancer has progressed. It reports the size of the primary tumor (T), whether or not it has spread to nearby lymph nodes (N), and whether or not it has metastasized, or spread to distant organs (M).
T Categories (Tumor)
T0: The tumor is too small to be measured.
T1: The tumor cannot be felt during a digital rectal exam, but a prostate biopsy detected cancer cells. There are three subcategories of the T1 level:
- T1a: The cancer is discovered by accident during an unrelated medical procedure to treat urinary problems caused by an enlarged prostate. T1a indicates that less than 5% of the tissue removed is cancer, and more than 95% is benign (not cancer).
- T1b: The cancer is discovered by accident, as described above, but more than 5% of the tissue removed is cancer.
- T1c: The cancer is discovered through biopsy, which may have been ordered because of a high PSA level suggesting the presence of cancer.
T2: The doctor can feel the tumor during a digital rectal exam, and it’s likely that the cancer has not moved outside the prostate.
- T2a: The cancer is on only one side of the prostate, and takes up only half (or less) of that side.
- T2b: The cancer is on only one side of the prostate, but takes up more than half that side.
- T2c: The cancer is on both sides of the prostate.
T3: The cancer has spread outside the outer edge of the prostate into the connective tissue next to the prostate and/or the seminal vesicles, and/or the opening of the bladder. However, the cancer has not spread to any other organs.
- T3a: The cancer is growing outside the prostate but has not spread to the seminal vesicles.
- T3b: Cancer has spread to the seminal vesicles.
T4: The cancer has spread to tissues next to the prostate (other than the seminal vesicles or opening of the bladder), such as the external sphincter (the muscle that controls urination), the rectum, muscles in the pelvis or the wall of the pelvis.
N Categories (Lymph Nodes)
NX: The tests to detect lymph node spread have not been done.
N0: The cancer has not spread to any lymph nodes.
N1: The cancer has spread to nearby lymph nodes in the pelvis.
M Categories (Metastasis)
M0: The spread of cancer cannot be detected by a physical exam or X-rays, but abnormal PSA blood tests indicate it is probably present.
M1: The cancer has spread to distant parts of the body.
M1a: The cancer has spread to distant lymph nodes.
M1b: The cancer has spread to bone(s).
M1c: The cancer has spread to other organs, such as the lung, liver or brain.
Recurrent cancer is cancer that has come back (recurred) after being in remission (a period of time when it could not be detected). It may recur in or near the prostate, or in any other part of the body, such as the bones.