HIV and cancer
What is HIV?
The human immunodeficiency virus (HIV) can be spread through contact with infected bodily fluids such as blood and semen. Most often, the virus is spread through sexual contact or sharing of needles. HIV then infects a type of cell called ‘T-cells’, which form part of the immune system that protects us from disease.
Once someone is infected with HIV, they are infected for life. More than 100,000 people in the UK live with HIV.
What cancers are linked to HIV?
HIV is linked to Kaposi Sarcoma and Non-Hodgkin Lymphoma. And it can also play a role in a number of other cancers, including Hodgkin Lymphoma and Human papillomavirus-linked cancers, such as cervical cancer.
Kaposi sarcoma is a very rare cancer with only a few hundred cases each year in the UK. Almost all cases of Kaposi sarcoma develop in people who have HIV.
Those who develop acquired immunodeficiency syndrome (AIDS) are at higher risk of cancer than those who do not develop AIDS.
How can HIV cause cancer?
People with HIV are 10 times more likely to develop a cancer that is caused by an infection than people in the general population. This is because HIV infects and destroys T-cells. T-cells are part of the immune system and can usually spot and destroy cells infected with cancer-causing viruses. This immune response can help to clear the infection before cancer can develop.
As HIV reduces the number of T-cells, the immune system doesn’t work as well, so other viruses such as Kaposi’s Sarcoma Herpes Virus (KSHV), Human herpesvirus-8 (HHV-8), Epstein-Barr virus (EBV) and Human papillomavirus (HPV) can more easily cause cells to grow and divide out of control, which can lead to cancer.
Reducing the risk
Since anti-retroviral therapy (ART) became available to control HIV, cases of cancers linked to HIV have gone down. So people infected with HIV can reduce their chances of developing cancers by taking ART to keep their infection under control.
The best way to avoid HIV-linked cancers is to avoid infection with the virus altogether. In the UK, the most common way to catch HIV is through unprotected sexual contact. So using a barrier method shown to reduce spread, like a condom, during sex is important. HIV can be spread between opposite-sex or same-sex partners.
There is also emergency medication for people who may have been exposed to the virus very recently. This has to be given within 3 days of exposure and is not always effective.