Individuals with HIV and AIDS are at increased risk of developing various types of cancer, including lymphoma. AIDS-related lymphoma occurs when malignant cells attack the lymphatic system. The lymph system is comprised of a complex network of tubules that carry lymphocytes, which are a type of white blood cell, throughout the body to fight against infection.
Definition & Facts
The lymphatic system is a vital part of the body’s immune system that includes the lymph vessels, lymph nodes, spleen, thymus, tonsils, and bone marrow. This system is responsible for the production, storage, and transportation of lymphocytes. The lymphocytes are carried through the system by a clear, watery fluid called lymph.
Lymphomas are classified as Hodgkin's lymphoma or non-Hodgkin's lymphoma. It is considered AIDS-related when it occurs in an individual with AIDS. The non-Hodgkin's form of lymphoma is more often seen in AIDS patients than the Hodgkin's form.
Non-Hodgkin AIDS-related lymphoma is often aggressive and can be categorized according to how the cells appear under a microscope. AIDS-related lymphoma falls into three basic categories that include
- Small non-cleaved cell lymphoma (also known as Burkitt's lymphoma.
- B-cell immunoblastic lymphoma
- Diffuse large B-cell lymphoma
Symptoms & Complaints
Because the lymphatic system runs throughout the body, the cancer can metastasize to other tissues and organs, including the spleen, brain, liver, or bone marrow, which can present with additional symptoms depending on the area affected.
The prognosis for those affected by AIDS-related lymphoma varies depending on the patient’s age, the number of areas to which the cancer has spread, the number of white blood cells called CD4 lymphocytes, and the patient’s ability to engage in normal daily activities.
AIDS occurs in individuals infected with the human immunodeficiency virus, also known as HIV. The virus attacks the body’s immune system so that it is no longer able to defend against infections or disease. Those infected with HIV are at greater risk for a wide range of opportunistic infections as well as various malignancies.
A person is considered to have AIDS when they develop a significant health condition in combination with an HIV infection. The diagnosis of lymphoma is often what leads to a person going from being HIV-positive to being diagnosed with AIDS. The actual cause of lymphoma itself is not clear; however, it is possible that the virus triggers DNA mutations that can cause lymphoma to develop.
Those most at risk for becoming infected with HIV and ultimately developing AIDS or AIDS-related lymphoma include individuals who have unprotected sex either - anal sex or vaginal sex or who share needles and syringes during intravenous drug use.
Although less common, HIV can also be spread from mother to infant during pregnancy, delivery, or breastfeeding. Health care and emergency personnel may become infected through accidental needle sticks or by contact with the blood of an infected person. In extremely rare cases, HIV has been spread through blood transfusions or the transplant of infected organs or tissues.
Diagnosis & Tests
The initial diagnosis of an HIV infection is made through a blood test that checks for HIV antibodies. If an individual is known to have HIV or AIDS and has symptoms of lymphoma, the doctor will perform a physical examination to check for swelling or lumps in the lymph nodes located in the neck, under the arms, or in the groin.
If abnormal lymph nodes are detected, a biopsy will usually be performed to remove a small sample of tissue for closer examination under a microscope. Once the diagnosis is confirmed, additional tests are used to determine the extent to which the cancer cells have metastasized to other areas of the body.
This may include blood chemistry studies, computed tomography (CT) scans and magnetic resonance imaging (MRI) scans of internal organs and tissues, positron emission tomography (PET) scans to highlight cancer cells in the body, and a lumbar puncture to identify cancer cells in the cerebrospinal fluid.
Stage I lymphoma is found in one area of the lymphatic system. Stage II lymphoma affects one or more groups of lymph nodes. Stage III lymphoma affects groups of lymph nodes located above as well as below the diaphragm. Stage IV lymphoma affects one or more organs outside of the lymphatic system. Each stage of AIDS-related lymphoma can also be designated as E or S. E indicates that cancer cells can be found in the tissues or organs near the lymphatic system. S means that the lymphoma has metastasized to the spleen.
Treatment & Therapy
AIDS-related lymphoma tends to grow faster and spread more aggressively than lymphoma in individuals without AIDS. Treatment is further complicated by the fact that the treatments used to treat lymphoma further weaken the immune system, which is already compromised by HIV.
This means that many of the anticancer drugs used to treat the lymphoma have to be used in lower doses. Highly-active antiretroviral therapy (ART) slows the replication of HIV and can allow some patients to receive chemotherapy drugs in higher doses. These drugs are administered orally or intravenously and work by killing the cancer cells or preventing them from dividing and replicating.
High-dose chemotherapy is often followed by a stem cell transplant to replace the blood-producing cells that are destroyed during the treatment. Internal or external radiation therapy uses various types of high-energy radiation to attack the cancer cells. For some patients, the best option may be to see if they qualify to participate in clinical trials investigating new drugs and targeted therapies.
Prevention & Prophylaxis
As a general rule, individuals with AIDS-related lymphoma have a life expectancy of approximately two months to two years. The only way to prevent AIDS-related lymphoma is to prevent becoming infected with HIV. This includes avoiding risky sexual behavior and avoiding IV drug use.