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AIDS Related Cancers
Introduction
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 visuali zing
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
Lymphomas are cancers of the lymphatic system, which is a 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
regimens 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 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.
Kaposi's Sarcoma
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 also are 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 anticancer 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.
Anogenital Cancers
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 to remove the anus and rectum.
Research
The National Institute of Allergy and Infectious Diseases (NIAID) funds
research aim ed at finding better treatments for AIDS-associated cancers. new
therapies currently are being evaluated for safety or effectiven ess in
NIAID-sponsored clinical trials.
For more information on or other studies, call the AIDS Clinical Trials
Information Service: 1-800-TRIALS-A.
For federally approved treatment guidelines on HIV/AIDS, call the HIV/AIDS
Treatment Information Service.
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