Types of Cancer - AIDS-Associated Cancers
< Back to List
AIDS is caused by the human immunodeficiency virus (HIV), which is a virus that attacks and breaks down the immune system -- the body's line of defense against infections and disease. As these defenses weaken, people with AIDS can develop one or more of a group of very serious infections and cancers. Certain cancer types are more likely to occur in people infected with AIDS -- the most common are Kaposi's sarcoma and non-Hodgkin's lymphoma.
Kaposi's sarcoma -- which can
appear as spots, or lesions, on the skin, mucous membranes (moist, inner lining of some organs and body cavities), lungs, and gastrointestinal tract (stomach and intestines) -- was one of the first recognized signs of HIV infection in the early 1980s. Although most cases of non-Hodgkin's lymphoma -- a group of cancers that arises in the lymphatic system -- are not AIDS-related, this type of cancer is 20 to 50 times more common among people infected with HIV than among
those without the virus. Lymphoma that arises in the central nervous system is almost 3,000 times more common in people with the HIV infection, but is very rare if someone is taking medicine (such as highly active antiretroviral therapy, or HAART) to treat the virus.
Non-Hodgkin's lymphoma, a group of cancers that originate in the lymphatic system -- the collection of lymph nodes, vessels, and organs that produces infection-fighting cells and carries them throughout the body -- is nearly 20 to 50 times more common among people infected with HIV than among those without the virus. Most cases of non-Hodgkin's lymphoma are not AIDS-related. The outcome for HIV-infected people who develop lymphoma continues to improve as doctors gain
insight into its causes, and as treatment for the disease advances.
In addition to more common symptoms of non-Hodgkin's lymphoma such as swollen lymph nodes, many patients with AIDS-associated lymphomas have so-called "B symptoms" -- fever, night sweats, and weight loss. They are also more likely to develop disease outside of lymph nodes -- in the liver, bone marrow, stomach, brain, mouth, and anus -- than those without HIV infection.
The majority of non-Hodgkin's lymphomas in HIV-positive patients are aggressive large-cell
lymphomas. Burkitt's lymphoma, a very fast-growing type of lymphoma, is also common among HIV-positive patients. People with HIV may also develop unusual HIV-associated lymphomas including primary effusion lymphoma, which usually arises in the lung cavity; plasmablastic lymphoma, which often develops in the jaws and mouth; and primary central nervous system lymphoma, which develops in the brain.
Treatment for AIDS-associated lymphomas almost always includes chemotherapy or, less often, radiation therapy. New research indicates that patients with immune systems supported by highly active antiretroviral therapy (HAART) tolerate and responded well to standard chemotherapy for non-Hodgkin's lymphoma.
Patients with AIDS-related lymphoma used to receive lower doses of chemotherapy drugs than other patients, but patients taking HAART can safely receive chemotherapy
drugs in doses used for those without HIV infection, likely improving their outcomes. Indeed, several studies, including one run by the AIDS Malignancy Consortium and conducted at Nazha Cancer Center, show that even patients with lymphomas that relapse, or that do not initially respond to therapy, can receive high-dose therapy with stem cell support (also known as an autologous transplant). (For more information about Transplantation, visit that section of our Web site.)
We are also studying intensive treatment approaches (without transplantation) in patients with AIDS-related Burkitt's lymphoma.
Rituximab, one of a class of drugs called monoclonal antibodies, targets lymphomas and improves the outcome in patients without HIV infection. Recent studies have shown rituximab may also help treat AIDS-related lymphoma. Current studies at Nazha Cancer Center and elsewhere are assessing the best ways to use rituximab in these patients.
AIDS-Associated Primary CNS Lymphoma
One type of non-Hodgkin's lymphoma that people with AIDS are particularly susceptible to is that of the central nervous system (CNS) -- the brain, spinal fluid, and eyes. This disease, primary CNS lymphoma, is 3,000 times more common in people with AIDS than in the general population.
AIDS-associated primary CNS lymphoma is most often a late complication, arising in patients with profoundly suppressed immune systems. CNS lymphomas occur mostly in people whose numbers
of CD4 T cells, immune cells that help other parts of the immune system respond to infection, are very low -- 50 and under -- and who have had other opportunistic infections. Symptoms include partial paralysis, seizures, confusion, and memory loss. At the time of diagnosis, the disease is usually dispersed throughout the brain and nervous system.
Physicians base the course of treatment on the patient's general condition. In patients whose overall health is good, treatment
may include chemotherapy. In patients whose condition is poor, physicians may use radiation therapy to alleviate the most troubling symptoms.
Epstein-Barr virus (EBV) is found in AIDS-associated primary CNS lymphomas and is believed to play a role in the development of the disease. One small study showed that AIDS patients might benefit from high doses of HAART and antiviral therapy targeting EBV.