HEALTH INSIGHTS

Prostate Cancer: Staging

April 06, 2018

Prostate Cancer: Staging

What does the stage of a cancer mean?

The stage of a cancer is how much and how far the cancer has spread in your body. Your healthcare provider uses exams and tests to find out the size of the cancer and where it is. He or she can also see if the cancer has grown into nearby areas, and if it has spread to other parts of your body. The stage of a cancer is one of the most important things to know when deciding how to treat the cancer.

The place where cancer starts is called the primary site. Prostate cancer can spread from the primary site to other parts of your body.  When a cancer spreads, it’s said to have metastasized. That's why you might hear cancer that has spread being called metastatic cancer.

 

The TNM system for prostate cancer

The most commonly used system to stage prostate cancer is the TNM system from the American Joint Committee on Cancer. Be sure to ask your healthcare provider to explain the stage of your cancer in a way you can understand.

The first step is to decide the value for each part of the TNM system. Here's what the letters stand for in the TNM system:

  • T tells how far the main tumor has spread into the prostate gland and nearby tissue.

  • N tells if the lymph nodes in the area of the original tumor have cancer in them.

  • M tells if the cancer has spread (metastasized) to distant organs in the body, such as the bones.

Numbers and letters after T, N, and M give more details about each of these factors. Higher numbers mean the cancer is more advanced.

Your PSA level when you were diagnosed and your grade group (which is based on your Gleason score) are also key pieces of information used during staging. (The Gleason score notes how different the cancer cells look from normal prostate cells.)

 

Stage groupings

Stage groupings are determined by combining the T, N, and M values from the TNM system. These groupings give an overall description of your cancer. A stage grouping is listed as a Roman numeral and can have a value of I through IV (1 through 4). The higher the number, the more advanced your cancer is.

These are the stage groupings of prostate cancer and what they mean:

Stage I. The cancer is grade group 1 (the Gleason score is less than 6), and your PSA at diagnosis was less than 10. The cancer has not spread to lymph nodes or distant parts of your body, and one of these is true:

  • The tumor can't be felt or seen on an ultrasound. The cancer was found during a TURP or a needle biopsy done because of a high PSA.

  • The tumor can be felt or seen on an ultrasound and is only in one-half or less of 1 side of the prostate gland.

  • Surgery was done to remove the prostate and the tumor was only in the prostate gland.

Stage II. The cancer has not spread to lymph nodes or distant parts of your body. This stage is divided into these groups:

  • Stage IIA. The cancer is grade group 1 (the Gleason score is less than 6) and one of these is true:

    • The tumor can't be felt or seen on an ultrasound. The cancer was found during a TURP or a needle biopsy done because of a high PSA. Your PSA at diagnosis was at least 10, but less than 20.

    • The tumor can be felt or seen on an ultrasound and is only in one-half or less of 1 side of the prostate gland, or surgery was done to remove the prostate and the tumor was only in the prostate gland. Your PSA at diagnosis was at least 10, but less than 20.

    • The tumor can be felt or seen on an ultrasound and is in more than one-half of 1 side of the prostate gland, or is in both sides of the gland. Your PSA at diagnosis was less than 20.

  • Stage IIB. The cancer is only inside the prostate gland. It may or may not be felt or seen on an ultrasound. It's in grade group 2 (the Gleason score is 3 + 4 =7), and your PSA at diagnosis was less than 20.

  • Stage IIC. The cancer is only inside the prostate gland. It may or may not be felt or seen on an ultrasound. It's in grade group 3 (the Gleason score is 4 + 3 =7 or 8), and your PSA at diagnosis was less than 20.

Stage III. The cancer has not spread to lymph nodes or distant parts of your body. This stage is divided into these groups:

  • Stage IIIA. The cancer is only inside the prostate gland. It may or may not be felt or seen on an ultrasound. It's in grade group 1 to 4 (the Gleason score is 8 or less), and your PSA at diagnosis was at least 20.

  • Stage IIIB. The cancer has grown outside the prostate gland and may be in the seminal vessicles or other tissues near the prostate, like the bladder, rectum, or wall of the pelvis. It's in grade group 1 to 4 (the Gleason score is 8 or less), and the PSA can be any value.

  • Stage IIIC. The cancer may or may not be growing outside the prostate gland and into tissues near the prostate. It's in grade group 5 (the Gleason score is 9 or 10), and the PSA can be any value.

Stage IV. The cancer may or may not be growing outside the prostate gland and into tissues near the prostate. It can be in any grade group and the PSA can be any value. Stabe IV is divided into these 2 groups:

  • Stage IVA. It has spread to nearby lymph nodes, but has not spread to distant parts of the body.

  • Stage IVB. The cancer may or may not have spread to nearby lymph nodes. It has spread to distant parts of your body, like distant lymph nodes, bones, or other organs.

Talking with your healthcare provider

The staging system for prostate cancer is complex. Ask your healthcare provider any questions you have about your stage and what it means for you. 

Updated:  

April 06, 2018

Sources:  

Prostate cancer TNM prognostic stage groups AJCC UICC 2017. UpToDate., Prostate cancer TNM staging AJCC UICC 2017. UpToDate.

Reviewed By:  

Alteri, Rick, MD,Gersten, Todd, MD