Prostate Cancer: Stages

This section has been reviewed and approved by the Cancer.Net Editorial Board, 09/2013

ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. To see other pages, use the menu on the side of your screen.

Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all of the tests are finished. Staging for prostate cancer also involves looking at test results to find out if the cancer has spread from the prostate to other parts of the body. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancer.

There are two types of staging for prostate cancer:

  • The clinical stage is based on the results of tests done before surgery, which includes DRE, biopsy, x-rays, CT scans, and bone scans. X-rays, bone scans, and CT scans may not always be needed. They are recommended based on the level of serum PSA, the grade and volume (size) of the cancer, and the clinical stage of the cancer.
  • The pathologic stage is based on information found during surgery, plus the laboratory results (pathology) of the prostate tissue removed during surgery (which often includes the removal of the entire prostate and some lymph nodes).

One tool that doctors use to describe the stage is the TNM system. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:

  • How large is the primary tumor and where is it located? (Tumor, T)
  • Has the tumor spread to the lymph nodes? (Node, N)
  • Has the cancer metastasized to other parts of the body? (Metastasis, M)

The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.

Below are more details about each part of the TNM system for prostate cancer.

Tumor. Using the TNM system, the "T" plus a number (0 to 4) is used to describe the size and location of the tumor. Some T groups are divided into smaller subgroups using the lowercase letters "a," "b," or "c" to help describe the tumor in even more detail.

TX: The primary tumor cannot be evaluated.

T0: There is no evidence of a tumor in the prostate.

T1: The tumor cannot be felt during a DRE and is not seen during imaging (any test that produces pictures of the inside of the body, such as a CT scan). It may be found when surgery is done for another reason, usually for BPH or an abnormal growth of noncancerous prostate cells.

T1a: The tumor is in 5% or less of the prostate tissue removed during surgery.

T1b: The tumor is in more than 5% of the prostate tissue removed during surgery.

T1c: The tumor is found during a needle biopsy, usually because the patient has an elevated PSA level.

T2: The tumor is found only in the prostate, not other parts of the body. It is large enough to be felt during a DRE.

T2a: The tumor has spread to one-half of one lobe (part or side) of the prostate.

T2b: The tumor has spread to more than one-half of one lobe of the prostate but not to both lobes.

T2c: The tumor has grown into both lobes of the prostate.

T3: The tumor has grown through the prostate capsule (into the tissue just outside the prostate) on one side.

T3a: The tumor has grown through the prostate capsule either on one side or on both sides of the prostate, or it has spread to the neck of the bladder.

T3b: The tumor has grown into the seminal vesicle(s), the tube(s) that carry semen.

T4: The tumor is fixed, or it is growing into nearby structures other than the seminal vesicles, such as the external sphincter (part of the muscle layer that helps to control urination), the rectum, levator muscles, and/or the pelvic wall.

Nodes. The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the prostate in the pelvic region are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes.

NX: The regional lymph nodes cannot be evaluated.

N0: The cancer has not spread to the regional lymph nodes.

N1: The cancer has spread to the regional lymph node(s).

Distant metastasis. The "M" in the TNM system indicates whether the prostate cancer has spread to other parts of the body, such as the lungs or the bones.

MX: Distant metastasis cannot be evaluated.

M0: The disease has not metastasized.

M1: There is distant metastasis.

M1a: The cancer has spread to nonregional, or distant, lymph node(s).

M1b: The cancer has spread to the bones.

M1c: The cancer has spread to another part of the body, with or without spread to the bone.

Cancer stage grouping

Doctors assign the stage of the cancer by combining the T, N, and M classification See the table below the stage descriptions for all of the TNM combinations for each stage.

Stage I: Cancer is found in the prostate only, usually during another medical procedure. It cannot be felt during the DRE or seen on imaging tests. A stage I cancer is usually made up of cells that look more like healthy cells and is likely to grow slowly.

Stage I Prostate Cancer

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Stage IIA and IIB: This stage describes a tumor that is too small to be felt or seen on imaging tests. Or, it describes a slightly larger tumor that can be felt during a DRE. The cancer has not spread outside of the prostate gland, but the cells are usually more abnormal and may tend to grow more quickly. It has not spread to lymph nodes or distant organs.

Stage IIA Prostate Cancer

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Stage IIB Prostate Cancer

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Stage III: The cancer has spread beyond the outer layer of the prostate into nearby tissues. It may also have spread to the seminal vesicles, the glands in men that help make semen.

Stage I Prostate Cancer

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Stage IV: This stage describes any tumor that has spread to other parts of the body, such as the bladder, rectum, bone, liver, lungs, or lymph nodes.

Stage IV Prostate Cancer

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Recurrent: Recurrent prostate cancer is cancer that has come back after treatment. It may come back in the prostate area again or in other parts of the body. If there is a recurrence, the cancer may need to be staged again (called re-staging) using the system above

Stage Grouping Chart

Stage

T

N

M

I

T1a, T1b, or T1c

N0

M0

 

T2a

N0

M0

 

Any T1 or T2a

N0

M0

 

 

 

 

IIA

T1a, T1b, or T1c

N0

M0

 

T1a, T1b, or T1c

N0

M0

 

T2a

N0

M0

 

T2b

N0

M0

 

T2b

N0

M0

 

 

 

 

IIB

T2c

N0

M0

 

Any T1 or T2

N0

M0

 

Any T1 or T2

N0

M0

 

 

 

 

III

T3a or T3b

N0

M0

 

 

 

 

 

 

 

 

IV

T4

N0

M0

 

Any T

N1

M0

 

Any T

Any N

M1

Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010), published by Springer-Verlag New York, www.cancerstaging.net

Prognostic factors

In addition to stage, doctors use other prognostic factors to help plan the best treatment and predict how successful treatment will be. Below are prognostic factors for men with prostate cancer.

PSA test. As described in the Risk Factors and Prevention section, PSA is a measurement of prostate-specific antigen levels in a man’s blood. These results are usually reported as nanograms per milliliter (ng/mL), such as 7 ng/mL for a PSA level of 7. For men already diagnosed with prostate cancer, the PSA level (and the Gleason score, described below) helps the doctor understand and predict a patient’s prognosis. This measurement gives doctors more information about the cancer to help make treatment decisions. Some prostate cancers do not cause an increased PSA level, so a normal PSA does not always mean that there is no prostate cancer.

Gleason score for grading prostate cancer. Prostate cancer is also given a grade called a Gleason score, which is based on how much the cancer looks like healthy tissue when viewed under a microscope. Less dangerous tumors generally look more like healthy tissue, and more dangerous tumors that are likely to grow and spread to other parts of the body look less like healthy tissue.

The Gleason System is the most common prostate cancer grading system used. The pathologist looks at how the cancer cells are arranged in the prostate and assigns a score on a scale of 1 to 5. Cancer cells that look similar to healthy cells are given a low score, and cancer cells that look less like healthy cells are given a higher score. To assign the numbers, the doctor determines the main pattern of cell growth (area where the cancer is most obvious), looks for any other less common pattern of growth, and gives each one a score. The scores are added to come up with an overall score between 2 and 10.

The interpretation of the Gleason score by doctors has changed recently. Originally, doctors used a wide range of scores. Today, doctors no longer use Gleason scores of 5 or lower for cancer found with a biopsy. The lowest score used is 6, which is a low-grade cancer. A Gleason score of 7 is a medium-grade cancer, and a score of 8, 9, or 10 is a high-grade cancer. A lower-grade cancer grows more slowly and is less likely to spread than a high-grade cancer.

Doctors look at the Gleason score in addition to stage to help plan treatment. For example, active surveillance (see the Treatment Options section) may be an option for a patient with a small tumor, low PSA level, and a Gleason score of 6. On the other hand, patients with high Gleason score (8-10) may need more intensive treatment even if it doesn’t appear that the cancer has spread.

Gleason X: The Gleason score cannot be determined.

Gleason 6 or lower: The cells are well differentiated.

Gleason 7: The cells are moderately differentiated.

Gleason 8, 9, or 10: The cells are poorly differentiated or undifferentiated.

Information about the cancer’s stage will help the doctor recommend a treatment plan.  The next section helps explain the treatment options for this type of cancer. Use the menu on the side of your screen to select Treatment Options, or you can select another section, to continue reading this guide.