Certain types of cancer occur so often in people with AIDS that they are considered AIDS-defining conditions – that is, their presence in a person infected with HIV is a clear sign that full-blown AIDS has developed. They are also called AIDS-related cancers and include the following:

• Kaposi sarcoma
• lymphoma (especially non-Hodgkin lymphoma and primary central nervous system lymphoma)
• invasive cervical cancer

Other types of cancer that may be more likely to develop in people with HIV infection are invasive anal cancer, Hodgkin disease, lung cancer, cancer of the mouth, cancer of the testicles, and skin cancers, including basal cell, squamous cell, and even malignant melanomas. Of course, people without HIV or AIDS can also have all of these types of cancer, even the ones that are better known as AIDS-related. They are only called AIDS-related cancers if they develop in people with HIV infection.

In developed countries, about 4 people in 10 with AIDS develop cancer at some time during their illness. However, the cancer picture in HIV is changing. Kaposi sarcoma and non-Hodgkin lymphoma have decreased as anti-retroviral treatment has become more common. Most other types of cancer do not seem to be slowed by HIV treatment, and have the same risk factors as those in people without HIV. For instance, people who smoke and have HIV are more likely to have cancers of the lip, mouth, throat, and lung than people who have HIV and don't smoke.

The relationship between HIV and these other cancers is still not completely understood. However, it is believed cancers can grow quickly because people with HIV have weakened immune systems. Unfortunately, cancer in people with HIV can be harder to treat. This is partly because of the decreased immune function caused by HIV and the lower white blood cell count that can result from HIV infection. Having AIDS can make it hard for a person to take chemotherapy because the bone marrow, which is needed to make new blood cells, is sometimes already damaged by the HIV infection. People with this problem often can't take the full dose of chemotherapy without serious harm. The introduction of highly active anti-retroviral therapy or HAART in the late 1990s led to a decrease in some types of cancer among those with HIV and better survival with anti-cancer treatment. It has also allowed full chemotherapy doses to be used for treatment. Other types of cancer treatment, such as monoclonal antibodies and stem cell transplant, are being studied in people with HIV.

AIDS-related Kaposi sarcoma

Kaposi sarcoma (KS) was once an uncommon disease that mainly affected older men of Mediterranean or Jewish ancestry, organ transplant patients, or young men in Africa. This form is called classic KS. However, in the 1970s and 80s the number of people with KS increased dramatically.

In the past 25 years, most KS cases in the United States have been linked to HIV infection in men who have sex with men. These cases are referred to as epidemic KS. It is now known that KS in people with HIV is related to a second viral infection. This virus is called human herpes virus 8 (HHV-8), also known as Kaposi sarcoma-associated herpes virus (KSHV). HHV-8 does not appear to cause disease in most healthy people. Infection with the virus is common in the United States among men who have sex with men, although it can also be transmitted through sex between men and women. The virus has been found in saliva, and deep kissing may be one of the ways it is passed to others.

In most cases, epidemic KS causes dark purplish or brownish spots (called lesions) that can show up at a number of places on the body. The spots may arise on the skin or in the mouth, and may affect the lymph nodes and other organs, such as the digestive tract, lung, liver, and spleen.

When they are first diagnosed, some people with epidemic KS have no other symptoms, especially if their only lesions develop on the skin. However, many – even those with no skin lesions – have swollen lymph nodes, unexplained fever, or weight loss. Over time, epidemic KS spreads throughout the body. If KS involves a lot of the lung or intestine, it can be fatal.

In general, people who are diagnosed with epidemic KS are started on anti-retroviral drugs, and often get treatment directed at the cancer itself. For more information about KS and its treatment, please see the American Cancer Society document, Kaposi Sarcoma.

Lymphomas

Non-Hodgkin lymphoma (NHL) occurs in about 4% to 10% of people with AIDS. It is a cancer that starts in lymphoid tissue and may spread to other organs. Since anti-retroviral therapy (ART) has been used, the number of HIV-infected people who develop lymphoma has declined, although not as much as KS.

The non-Hodgkin lymphomas that typically occur in people with AIDS are often primary central nervous system (CNS) lymphomas. Primary CNS lymphoma starts in the brain or spinal cord. Symptoms of CNS lymphoma can include seizures, facial paralysis, confusion, memory loss, and lethargy (tiredness). AIDS-related non-Hodgkin lymphomas can also include certain types of intermediate and high-grade lymphomas, including Burkitt lymphoma.

The prognosis, or outcome, for patients with AIDS-related NHL depends partly on the type of lymphoma and partly on the person's immune function. People with advanced NHL, a CD4 T-cell count less than 200, and/or who don't get ART don't usually do as well as people without these factors.

It seems the best treatment for AIDS-related NHL is getting more and more like treatment of NHL in those without HIV infection. At one time, treatment was made up of low doses of chemotherapy. But with ART, many patients are treated with the standard combinations of chemotherapy drugs that are used in people without AIDS. The use of blood-cell forming (hematopoietic) growth factors added to chemo also shows promise in HIV-infected patients.

For patients with primary CNS lymphoma, chemotherapy or whole-brain radiation may be used. ART is used to improve immune function and prolong survival.

For more information on HIV/AIDS-associated NHL and its treatment, please see the American Cancer Society document, Non-Hodgkin Lymphoma.

Pre-cancerous cervical changes and invasive cervical cancer

HIV-infected women are at high risk for developing cervical intraepithelial neoplasia (CIN). CIN is the growth of abnormal, pre-cancerous cells in the cervix, the lower part of the uterus (womb). Over time, CIN can progress to invasive cervical cancer, in which the cancer cells grow into deeper layers of the cervix (and may eventually spread elsewhere).

CIN must be treated effectively (by removing or destroying the outer layers of cervical cells) to keep it from progressing to invasive cancer. Studies have shown that untreated CIN is more likely to progress to invasive disease in HIV-infected women than in women who don't have HIV. The standard treatment for CIN does not work as well in HIV-infected women as it does in women without HIV. The chance of the disease coming back (recurring) after treatment is high, which seems related to the woman's immune function. Women with CD4 counts less than 50 are at high risk for CIN recurring.

HIV-infected women with invasive cervical cancer and a good immune function generally do well with surgery and the same treatments that women without HIV get. Those who have more advanced disease respond poorly to radiation therapy alone. In women with advanced or recurrent disease, chemotherapy has been used, though the woman must be watched closely afterward to be sure the cancer doesn't come back. During cancer treatment, the woman's immune status must be monitored and her HIV infection treated. Anti-retroviral drugs are usually given to improve the treatment outcome for HIV-infected women with invasive cervical cancer, regardless of CD4 counts.

Women with AIDS and cervical cancer tend not to do as well as women who do not have AIDS. Women with CD4 counts higher than 500 tend to fare better.

For more detailed information on cervical cancer and its treatment, please see the American Cancer Society document, Cervical Cancer.

Non-AIDS -related cancers

With more widespread use of anti-retroviral drug treatment, AIDS-related cancers are happening less often. But as people with HIV are living longer, they are developing cancers that are not generally linked to HIV, such as lung, throat, liver, intestinal, and anal cancers as well as Hodgkin disease and multiple myeloma. Most of the time, treatment includes ART along with cancer treatments that have worked for people without HIV. At the same time, any other needed treatments for HIV (such as antibiotics to prevent infections) are used.