We also discuss how people with HIV can lower their cancer risk and how doctors treat cancer in these individuals.
HIV and cancer risk
People with HIV are at a higher risk of cervical cancer, lung cancer, and lymphoma.
HIV affects the body's immune system by specifically targeting CD4 cells, which are a type of white blood cell. If left untreated, HIV can reduce this cell count.
Generally, the higher a person's CD4 cell count, the better. Low levels of CD4 cells leave the body vulnerable to infections. Research from 2016 also shows that lower levels CD4 cells reduce the body's ability to fight off early forms of cancer.
People with HIV are at higher risk of certain cancers compared with individuals without HIV. These cancers include:
Kaposi's sarcoma is a rare form of cancer that develops in the cells that line the mouth, nose, throat, and blood vessels.
It causes red or brown tumors, or lesions, on the skin or mucous membranes. These tumors can appear in other areas of the body, such as the legs, lymph nodes, and digestive tract.
Kaposi's sarcoma commonly occurs in people with HIV. This is one of the conditions that healthcare providers use to diagnose stage 3 HIV.
Lymphoma is a form of blood cancer that affects the body's lymph system. It develops in the lymphocytes, which are a type of white blood cell.
Lymphoma can affect any part of the body where lymph tissue is present, including the:
- bone marrow
- lymph nodes
- digestive tract
There are two main types of lymphoma:
- Hodgkin lymphoma refers to lymphomas that produce a specific type of cell called a Reed–Sternberg cell. Hodgkin lymphoma usually starts developing in B cells, which are special lymphocytes that produce antibodies.
- Non-Hodgkin lymphoma refers to any type of lymphoma in which the Reed–Sternberg cell is absent. Non-Hodgkin lymphoma usually starts in lymph tissue, but it can affect the skin. Like Kaposi's sarcoma, healthcare providers use non-Hodgkin lymphoma to diagnose stage 3 HIV.
In the early stages of the disease, precancerous cells begin to grow in the lining of the cervix. If left untreated, these precancerous cells can develop into malignant cancer cells and grow deeper into the cervix. Doctors call this invasive cervical cancer.
In the United States, women with HIV are 66 percent more likely to develop cervical cancer than those without.
Lung cancer develops when the cells in a person's lungs mutate and grow uncontrollably to form tumors. These tumors continue to grow and destroy the healthy cells that make up the lining of the lungs.
Anyone can get lung cancer. Genetics and exposure to hazardous chemicals and air pollution are risk factors for lung cancer.
However, smoking is the leading cause of lung cancer. According to the American Lung Association, smoking is responsible for 90 percent of lung cancer cases.
According to the Centers for Disease Control and Prevention (CDC), in 2009, rates of smoking in the U.S. were more than twice as high among people receiving treatment for HIV than for the general population.
Anal cancer develops in the cells in and around the anus. Although anal cancer is relatively rare in the general population, it is more common among people living with HIV.
A study from 2012 that examined anal cancer rates among people with and without HIV found that men who have sex with men (MSM) who have HIV are at the highest risk for anal cancer.
The ANCHOR study group estimates that 1 in 10 MSM living with HIV will get anal cancer over their lifetime.
Oral and oropharyngeal cancer
Oral cancer affects the mouth. People who have oral cancer can develop tumors on the tongue and the lining of the lips, cheeks, and gums. Pharyngeal cancer affects the walls of the throat, tonsils, and the back of the tongue.
Smoking can increase the risk of cancer.
People with HIV are at higher risk of certain forms of cancer due to the effects that HIV can have on the immune system.
Some other factors that may increase the risk of cancer include:
- using injected drugs
- consuming alcohol
- eating an unhealthful diet
Many of the cancers that people with HIV are at higher risk of are related to other viruses. For example, there is an association between:
- Kaposi's sarcoma and human herpes virus 8
- anal cancer, oral cancer, and pharyngeal cancer and HPV
Co-infections, which occur when a person contracts two or more separate viruses, are more common in people with HIV.
According to a 2016 review, one-third of people with HIV also have the hepatitis C virus (HCV). A 2017 review concluded that there is a link between HCV infection and an increased risk of liver, pancreatic, and anal cancer in older people.
Lowering cancer risk
While people with HIV may be at higher risk for certain types of cancers, there are some ways to lower this risk.
Some lifestyle changes that can reduce the risk of cancer in people living with HIV include:
- not smoking or using tobacco products
- not using injected drugs
- limiting alcohol consumption
- exercising regularly
- eating a balanced and healthful diet
Some other ways of lowering the risk of cancer in people living with HIV include:
- taking HIV medications as prescribed
- taking part in cancer screenings
- getting vaccinated against cancer-associated viruses
Cancer treatment in people with HIV
Cancer treatment for people with HIV has improved due to advances in HIV treatment. In the past, healthcare providers were less likely to give full doses of chemotherapy or radiation therapy due to the effects of these treatments on the immune system.
Today, people with HIV typically receive the same treatment that anybody else might. However, doctors will closely monitor the CD4 cell counts of people who are receiving both HIV treatment and chemotherapy.
Detecting and treating HIV early also significantly reduces a person's risk of developing cancers such as Kaposi's sarcoma and non-Hodgkin lymphoma.
Due to the effects that the virus can have on a person's immune system, those living with HIV have a higher risk of developing certain types of cancer. These cancers include Kaposi's sarcoma, non-Hodgkin lymphoma, and cervical, lung, anal, and oral cancer.
However, advances in treatment mean that detecting and treating HIV early can significantly reduce the risk of developing these cancers.