HEALTH INSIGHTS

Anal Cancer: Stages

June 23, 2018

Anal Cancer: Stages

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 spread to 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.

Anal cancer starts in the inner lining of the anus. As anal cancer grows, it can grow through the layers of the wall of the anus. Then, like all cancers, it can spread (metastasize) to other parts of the body. 

The TNM system for anal cancer

The most commonly used system to stage anal cancer is the TNM system from the American Joint Committee on Cancer (AJCC). Be sure to ask your healthcare provider to explain the stage of your cancer to you 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 lining of your anus 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 liver or lungs.

Number or letters after T, N, and M provide more details about each of these factors.

What are the stage groupings of anal cancer

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 the cancer is.

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

Stage 0. The cancer is only found in the top layer of the lining of anal tissue. This stage is sometimes called anal carcinoma in situ.

Stage I. The cancer is less than 2 centimeters (cm), or about 1 inch across. It hasn't spread to lymph nodes or other organs.

Stage II. This stage is divided into two groups:

  • Stage IIA. The cancer is more than 2 cm but less than 5 cm across. It hasn't spread to nearby lymph nodes or other organs.

  • Stage IIB. The cancer is more than 5 cm across. It hasn't spread to nearby lymph nodes or other organs.

Stage III: This stage is divided into three groups:

  • Stage IIIA means either:

    • The cancer is 2 cm or less across and has spread to lymph nodes innear the rectum. It hasn't spread to distant organs.

    • The cancer is more than 2 cm but less than 5 cm across and has spread to lymph nodes near therectum. It hasn't spread to distant organs.

  • Stage IIIB. The cancer is any size and has spread to nearby organs, such as the vagina, prostate, or bladder.  It has not spread to nearby lymph nodes or to distant organs.

  • Stage IIIC. means either:

    • The cancer is more than 5 cm across and has spread to lymph nodes near the rectum. It hasn't spread to distant organs.

    • The cancer is any size and has spread to nearby organs, such as the vagina, prostate, or bladder, and has spread to lymph nodes near therectum. It hasn't spread to distant organs. 

Stage IV: The cancer can be any size. It may have spread to nearby lymph nodes or organs. It has spread to distant organs in other parts of the body, such as the liver or lungs.

Talking with your healthcare provider

Once your cancer is staged,  talk with your healthcare provider  about what the stage means for you. Make sure to ask questions and talk about your concerns.

Updated:  

June 23, 2018

Sources:  

Anal Cancer. AJCC Cancer Staging Manual. 2017, 8th ed., pp. 275-284., Principles of Cancer Staging. AJCC Cancer Staging Manual. 2017, 8th ed., pp. 3, 7-10.

Reviewed By:  

Cunningham, Louise, RN,Stump-Sutliff, Kim, RN, MSN, AOCNS