One in three people will develop cancer in their lifetime. There are over 200 types of cancer and three of these are classified as 'AIDS defining' cancers. This means they are more likely to occur if you are HIV positive and have a CD4 count below 200. These are Kaposi's sarcoma (KS), cervical cancer and non-Hodgkin's lymphoma.

Some cancers are more common in people with HIV despite not being 'AIDS defining'. This may be because the underlying cause of some cancers is viral. Anal cancer is linked to the human papillomavirus (HPV) which is a common virus that is passed on sexually. HPV also causes cervical cancer and some head, neck and oral cancers. Other cancers which are linked to viruses and have higher rates in people with HIV include Hodgkin's lymphoma (linked to the Epstein Barr virus) and liver cancer (which can be related to Hepatitis B or C viruses).
Most cancers are treated with radiotherapy or chemotherapy, although the AIDS-related cancers respond well to antiretroviral treatment. KS, where purple lesions appear on the skin and sometimes on the outside of internal organs, is linked to the Human herpes virus 8. If you are diagnosed with KS, you will usually be given antiretroviral treatment in the first instance as this often causes it to disappear, although if you have KS inside your body you may need to have radiotherapy or other treatment.
Because people with HIV are now living longer they have an increased chance of developing cancers generally associated with older age which are not linked to having HIV. Small changes to your lifestyle factors can reduce your risks of developing cancer such as improving your diet, getting enough exercise, getting enough rest and cutting down on alcohol. Starting antiretroviral treatment when your CD4 count is over 350 can also be preventative.

If you are diagnosed with cancer, you will be looked after by a cancer specialist as well as your HIV clinic. There are different treatments for cancer which are determined by the type of cancer you have. For example you could have a combination of chemotherapy, radiotherapy, surgery or other treatments.