Studies confirm that HIV-infected patients are more likely to develop certain types of cancer than HIV-negative people, due largely to the weakened immune system caused by the HIV infection.
Moreover, three types of cancer confirm the presence of AIDS in HIV-positive patients: Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. In addition to these three cancers – known as AIDS-defining cancers – a range of others have been found to be more prevalent among those with HIV infection than those without it.
This blog post will explore the increased risk of cancer among HIV-positive patients and how it is related to cancer deaths.
People infected with the human immunodeficiency virus (HIV) are more at risk of developing cancer than those not infected. Collectively, the cancers associated with HIV are referred to as “HIV-associated cancers.”
HIV-associated cancers can be further divided into AIDS-defining cancers and non-AIDS-defining cancers.
The discovery of three specific cancers that, when present in HIV-positive patients, confirm the presence of full-blown AIDS is perhaps the most significant finding in HIV/cancer research to date. These three cancers are Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer.
According to AIDS research, compared with the general population, HIV-positive people are 500 times more likely to develop Kaposi sarcoma, 12 times more likely to develop non-Hodgkin lymphoma, and, for women, three times more likely to develop cervical cancer.
- Kaposi sarcoma (KS)
KS is a form of AIDS-related cancer that causes lesions on the skin, mouth, nose, and throat. It is the most common AIDS-defining cancer. KS occurs when certain cells in the body – called endothelial cells – turn into tumor cells.
KS can also affect other body parts, such as internal organs like the lungs, liver, and digestive tract.
This type of cancer is associated with a viral infection called human herpesvirus 8, or HHV-8. This virus is also known as Kaposi sarcoma-associated herpesvirus. It usually doesn’t cause disease in healthy people, but it can cause KS in people with a weakened immune system.
- Non-Hodgkin lymphoma (NHL)
NHL is a cancer of the lymphatic system and begins in cells called lymphocytes in the lymph nodes. There are many different types of NHL, some of which are more common in HIV-positive people than in the general population. Those types include primary central nervous system lymphoma, Burkitt lymphoma, and aggressive B-cell NHL.
While KS is rarely found in people without HIV, NHL can often be found in HIV-negative people as well.
- Cervical cancer
Cervical cancer is a type of cancer that begins in the cells of the cervix – the lower part of the uterus. Worldwide, cervical cancer is the fourth most common type of cancer in women.
Like KS, cervical cancer is also linked to an HPV infection – a viral infection with a human papillomavirus virus, or HPV. There are many different types of HPV, some of which can cause cervical cancer.
HIV-positive women are at a higher risk of developing abnormal, pre-cancerous cells in the cervix called cervical intraepithelial neoplasia. These abnormal cells can lead to cervical cancer if not treated.
In addition to the three AIDS-defining cancers, a range of other cancers have been found to be more prevalent among people with HIV infection than those without it. Some of these include:
- Anal cancer (19 times more likely)
- Hodgkin lymphoma (8 times more likely)
- Liver cancer (3 times more likely)
- Lung cancer (2 times more likely)
- Mouth and throat cancers (2 times more likely)
Why do HIV-infected individuals have a higher risk of cancer?
The association between HIV/AIDS and the abovementioned cancers is not fully understood. However, researchers believe that the higher risk of cancer among people with HIV/AIDS may be due to several factors.
- Viral infections
KS and cervical cancer are not the only cancers associated with viruses. Many other cancers, including liver and mouth, are linked to viral infections.
For example, the Epstein-Barr virus is linked to many different types of cancer, including both Hodgkin lymphoma and non-Hodgkin lymphoma. Viruses Hepatitis B and C both cause liver cancer.
It is thought that people with a weakened immune system are more susceptible to these viruses and that their infection may increase the risk of cancer.
- Compromised immune system
The immune systems of people with HIV are compromised, at least in part because their T-cells do not function properly.
This makes them more vulnerable to infections and allows these infections to progress into cancer or precancerous cells. Additionally, immunosuppression and resulting inflammation in the body may directly or indirectly affect cancer development.
- Lifestyle risk factors
Certain traditional cancer risk factors, such as smoking, poor diet, and heavy alcohol use, are more prevalent among people with HIV. Reasons for this are not yet fully understood.
Some risk factors are increased due to improved HIV treatment protocols. For example, with the introduction of ART (antiretroviral therapy), the HIV wasting syndrome has largely disappeared. As a result, risk factors such as obesity and metabolic syndrome have increased in HIV-positive people.
Cancer Death Risk
Aside from having a higher risk of certain cancers, HIV-positive patients also have a higher risk of dying from cancer.
It is largely unknown why people with HIV have poorer outcomes in the case of cancer treatment. At least in part, this is also a result of a weakened immune system. It has also been postulated that this may be due to factors such as reduced access to healthcare services and poor adherence to medication – both of which are common problems among patients living with HIV/AIDS.
Cancer also tends to be discovered at a later stage in people with HIV and AIDS, often because they do not attend screenings as frequently as people without these diseases or are not screened for cancer at all.
cART and cancer
A type of HIV medication, combination antiretroviral therapy (cART), introduced in 1996, has dramatically improved the prognosis for people living with HIV/AIDS, leading to a substantial increase in life expectancy. This therapy includes a combination of three or more antiretroviral drugs, including:
- Zidovudine (AZT)
- Lamivudine (Epivir)
- Didanosine (ddI, Videx)
- Stavudine (d4T, Zerit)
- Efavirenz (EFV, Sustiva)
- Nevirapine (Viramune)
- Ritonavir (Norvir)
- Saquinavir (Invirase)
- Atazanavir (Reyataz), and similar.
For many years, it was unclear whether cART impacted cancer rates among people with HIV; however, more recent studies have shown that cART does indeed reduce the risk of cancer, especially Kaposi sarcoma and NHL.
This may be because cART helps partially restore immune function, allowing the body to fight off infections and cancer cells.
However, cART does not completely eliminate cancer risk in people with HIV precisely because it does not restore complete immune function. Thus, it is still important to be aware of the symptoms and report them to a doctor if they arise.
Do people with HIV have a higher risk of cancer? The answer is yes – people living with HIV are more likely to develop certain types of cancer, including Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. However, this does not mean that everyone with HIV will get cancer; many people living with HIV go their whole lives without developing any cancer.
The risk of dying from cancer is also higher among people with HIV; this may be due to a reduced immune function or other lifestyle factors.
cART has been shown to reduce the risk of certain cancers such as Kaposi sarcoma and NHL; however, it is still important for people living with HIV to be aware of the symptoms.
Innovative medicine is needed to help fight the battle of HIV-related cancers and beyond. Please donate to support the development of cancer-fighting solutions. Your donation can help bring new treatments and tools to better detect and treat cancer.