Kaposi Sarcoma: Stages

What does the stage of a 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 spread to 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 stages of AIDS-related Kaposi sarcoma (KS), the most common type of KS in the United States, is somewhat different from the stages of most other types of cancer. That’s because it takes into account factors other than the cancer itself.

Most healthcare professionals use the staging system for Kaposi sarcoma that was developed by the AIDS Clinical Trials Group. This system determines the stage of KS by three factors. These factors are identified by 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.

Healthcare providers divide each of these factors into two subgroups. In these subgroups, 0 stands for a lower risk of problems, and 1 stands for a higher risk of problems. Here's what the staging groups then mean:

Tumor status

• T0. KS is only in the skin and lymph nodes. There may also be a little KS in the mouth. The lesions are flat and are mainly on the roof of the mouth.

• T1. KS lesions are widespread. There may be swelling or sores due to the tumor, many lesions in the mouth, raised lesions, or KS in other organs in the body, like the liver, intestines, or lungs.

Immune system status

• I0. CD4 cell count is 150 or more cells per mm3 (cubic millimeter).

• I1. CD4 cell count is lower than 150 cells per mm3.

Systemic illness status

• S0. There is: 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 B symptoms are present, or the ability to do daily tasks and self-care 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.

So good risk might be written as any of these: T0 S0, T1 S0, or T0 S1.

Poor risk is written as T1 S1.

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.