Several cancers are more common or more aggressive in people infected with HIV, the virus that causes AIDS. These malignancies include certain types of immune system cancers known as lymphomas, Kaposi's sarcoma (KS) and anogenital cancers primarily affecting the cervix and anus. HIV or the immune suppression it induces appears to play a role in the development of these cancers.
Doctors diagnose the cancers common in people with AIDS by visualizing suspected cancerous tissues with magnifying devices and removing small samples of the tissue. The tissue samples are then examined under a microscope for distinctive cancerous cells. Doctors also may use X-rays, computerized tomography (CAT) scans or magnetic resonance imaging (MRI) scans of the suspected cancerous areas to aid diagnosis.
Lymphomas are cancers of the lymphatic system, which is part of the immune system that defends the body against disease. The lymphatic system is made up of a network of vessels that carry lymph, a colorless fluid that contains lymphocytes, infection-fighting white blood cells. Other parts of the lymphatic system include the lymph nodes, which are bean-shaped nodules located throughout the body but concentrated in the groin, neck, underarms, and abdomen.
The types of lymphomas most commonly associated with HIV infection are called non-Hodgkins lymphomas or B-cell lymphomas. In these types of cancers, certain cells of the lymphatic system grow abnormally. They divide rapidly, growing into tumors.
Lymphomas also can affect the liver, bone marrow or spleen. Swollen lymph nodes are the most common symptom, but other symptoms can occur, including fevers, weight loss, fatigue, abdominal pain and vomiting. People with central nervous system lymphomas, in which the brain or spinal cord is affected, can develop confusion, loss of memory or speech, seizures or headache.
Treating a person with HIV-related lymphoma often proves difficult because the immune system is already weakened by HIV, and standard chemotherapy regimes will further suppress immune function. Doctors prescribe specific treatment regimens depending on the stage of the disease, the type of lymphoma the patient has, other opportunistic diseases and the immune cell levels.
Either radiation therapy or a combination of anti-cancer drugs can be used to combat AIDS-related lymphomas. Chemotherapy can cause nausea, vomiting, fever, diarrhea, hair loss and a loss of immune cells. To protect the immune system, the growth factors GM-CSF or G-CSF may be prescribed to stimulate the bone marrow to boost production of white blood cells. Radiation generally is used to treat patients with lymphoma originating in the central nervous system.
KS is a disease in which cancerous cells are found in the tissues under the skin or in mucous membranes that line the mouth, nose or eye. KS also can spread to the lungs, liver, gastrointestinal tract and lymph nodes. People with KS often develop raised, usually painless blotches on the skin or inside the mouth. The blotches appear reddish-purple in light skinned people and bluish or brownish black in dark skinned people. When KS occurs in the gastrointestinal tract, it can cause bleeding; KS may result in difficulty in breathing when it affects the lungs. KS can cause painful swelling, especially in the legs.
The disease often is neither life-threatening nor disabling in people with AIDS, so treatment may not be necessary. Doctors usually recommend therapy if KS is widespread and painful or uncomfortable, or causing respiratory symptoms or swelling. KS patients are also treated if the disease is rapidly progressing or a cosmetic problem. If KS is not widespread, doctors can use radiation directed at tumor sites on the skin. Doctors also can remove lesions surgically or destroy them by freezing the tissue with liquid nitrogen or by injecting them with anti-cancer drugs.
Patients with advanced, widespread (disseminated) or rapidly progressing KS usually are treated with anti-cancer drugs used singly or in combination. As with lymphoma treatment, growth factors may be prescribed to counter the immune suppression induced by the chemotherapy.
Alpha interferon may be effective in treating patients with KS who have relatively healthy immune systems, as measured by the levels of certain immune cells in the blood and an absence of other major opportunistic diseases.
Immune suppression may make people with AIDS more susceptible to cancers of the cervix or anus that are associated with human papillomavirus infection (HPV). Cancer of the cervix usually occurs without symptoms, although it can cause abnormal vaginal bleeding. Anal cancer can cause red patches on the anus.
Pap smears, in which a scraping of cells is taken from the cervix, can detect cervical cancer at its earliest stage when treatment is highly effective. Women who are infected with HIV should receive Pap smears every 6 to 12 months to detect abnormal cervical cells that may develop into cancerous cells if left untreated.
Early cervical cancer is managed by burning, freezing or laser destruction of abnormal cells or by surgical removal of affected tissue. More advanced cervical cancer is treated by surgically removing the cervix and uterus, and sometimes the upper vagina and lymph nodes in the area as well, or by radiation or chemotherapy.
Doctors sometimes treat patients with anal cancers by surgically removing the tumorous tissues. For some patients, however, radiation therapy may be required, or it may be necessary to remove the anus and rectum.
The National Institute of Allergy and Infectious Diseases (NIAID) funds research aimed at finding better treatments for AIDS associated cancers. Several new therapies currently are being evaluated for safety or effectiveness in NIAID-sponsored clinical trials. For more information on these or other studies, call the AIDS Clinical Trials Information Service: 1-800-TRIALS-A (1-800-874-2572).
Office of Communications National Institute of Allergy and Infectious Diseases National Institutes of Health Bethesda, MD 20892 November 1994