Kaposi Sarcoma: Stages

What does stage of cancer mean?

For most types of cancer, the stage is a description of 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 the body. The stage of a cancer is typically one of the most important things to know when deciding how to treat the cancer.

What are the stages of Kaposi sarcoma?

The staging of AIDS-related Kaposi sarcoma (KS), the most common type of KS in the United States, is somewhat different from the staging of most other types of cancer. That’s because it takes into account factors other than the cancer itself. The main staging system for Kaposi sarcoma was developed by the AIDS Clinical Trials Group. This system determines the stage of KS by 3 factors. Doctors refer to these factors using the letters T, I, and S:

  • T is for the extent of the tumor in the body.

  • I is for the health of the immune system. This is measured by the CD4 cell count from a blood test.

  • S is for the extent of systemic illness in the body.

Doctors divide each of these factors into 2 subgroups. In these subgroups, 0 stands for a lower risk of problems, and 1 stands for a higher risk of problems:

  • T0. KS is confined to the skin and lymph nodes. There is little KS in the mouth. The lesions are flat and are mainly on the roof of the mouth.

  • T1. The tumor is widespread. There may be swelling due to the tumor, many lesions on the mouth, raised lesions, or KS in other organs in the body.

  • I0. CD4 cell count is 200 or more cells per cubic millimeter.

  • I1. CD4 cell count is lower than 200 cells per cubic millimeter.

  • S0. No history of additional infections that occur because of a weakened immune system (called opportunistic infections). No history of fungal infection of the mouth (called thrush). No B symptoms (unexplained fever, night sweats, unexpected weight loss of more than 10%, or diarrhea lasting for at least 2 weeks). You are up and about most of the time and can take care of yourself.

  • S1. Systemic illness is present, such as a history of opportunistic infections, thrush, or another HIV-related disease, such as lymphoma. Or you have B symptoms, or your ability to do daily tasks and take care of yourself is limited.

These factors are then combined to assign an overall risk group (good risk or poor risk). As treatment for HIV has become more effective in recent years, the immune status (I) has become less important in figuring out the risk group.

Talking with your healthcare provider

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