Kaposi Sarcoma: Risk Factors

What is a risk factor?

A risk factor is anything that may increase your chance of having a disease. Risk factors for a certain type of cancer might include smoking, diet, family history, or many other things. The exact cause of someone’s cancer may not be known. But risk factors can make it more likely for a person to have cancer.

Things you should know about risk factors for cancer:

• Risk factors can increase a person's risk, but they do not necessarily cause the disease.

• Some people with risk factors never develop cancer. Other people can develop cancer and have few or no risk factors.

• Some risk factors are very well known. But there is ongoing research about risk factors for many types of cancer.

Some risk factors, such as family history, may not be in your control. But others may be things you can change. Knowing the risk factors can help you make choices that might lower your risk. For example, if an unhealthy diet is a risk factor, you may choose to eat healthy foods. If excess weight is a risk factor, you may decide to try to lose weight.

Who is at risk for Kaposi sarcoma?

Anyone can get Kaposi sarcoma (KS). But there are some factors that can increase your risk for KS, such as:

• Gender. Men have a higher risk of KS than women. 

• Ethnic background. People of Mediterranean or Jewish descent and people living in certain parts of Africa have a higher risk of some types of KS.

• Infection with human herpes virus-8 (HHV-8). Infection with this virus, also known as Kaposi sarcoma-associated herpes virus (KSHV), seems to be necessary for KS to develop. But most people infected with this virus do not go on to develop KS.

• Having a weakened immune system. People with a weakened immune system, such as people infected with HIV (the virus that causes AIDS) or people who have had an organ transplant, are at increased risk for KS. This is likely because their weakened immune system is not able to keep an HHV-8 infection under control.

• Sexual orientation. Men who have sex with men are at increased risk for KS. This is probably because they are more likely to be infected with both HHV-8 and with HIV.

What are your risk factors?

Talk with your healthcare provider about your risk factors for KS and what you can do about them. Some risk factors, such as your gender and ethnicity, are not under your control. But there might be things you can do, such as limiting your risk of infection with HIV, that might lower your risk of KS. 

If you are infected with HIV, talk to your healthcare provider about what you can do to help keep your immune system strong. Also talk about any symptoms you should look for that might be early signs of KS.