AIDS-related lymphoma is a disease in which malignant (cancer) cells form in the lymph system of patients who have acquired immunodeficiency syndrome (AIDS).
AIDS is caused by the human immunodeficiency virus (HIV), which attacks and weakens the body's immune system. The immune system is then unable to fight infection and diseases that invade the body. People with HIV disease have an increased risk of developing infections, lymphoma, and other types of cancer. A person with HIV disease who develops certain types of infections or cancer is then diagnosed with AIDS. Sometimes, people are diagnosed with AIDS and AIDS-related lymphoma at the same time. For information about AIDS and its treatment, please see the AIDSinfo Web site.
Lymphomas are cancers that affect the white blood cells of the lymph system, part of the body's immune system. The lymph system is made up of the following:
- Lymph: Colorless, watery fluid that travels through the lymph system and carries white blood cells called lymphocytes. Lymphocytes protect the body against infections and the growth of tumors.
- Lymph vessels: A network of thin tubes that collect lymph from different parts of the body and return it to the bloodstream.
- Lymph nodes: Small, bean-shaped structures that filter substances in lymph and help fight infection and disease. Lymph nodes are located along the network of lymph vessels found throughout the body. Clusters of lymph nodes are found in the underarm, pelvis, neck, abdomen, and groin.
- Spleen: An organ that produces lymphocytes, filters the blood, stores blood cells, and destroys old blood cells. It is located on the left side of the abdomen near the stomach.
- Thymus: An organ in which lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.
- Tonsils: Two small masses of lymph tissue at the back of the throat. The tonsils produce lymphocytes.
- Bone marrow: The soft, spongy tissue in the center of large bones. Bone marrow produces white blood cells, red blood cells, and platelets.
There are many different types of lymphoma.
AIDS-related lymphomas grow and spread quickly.
Non-Hodgkin's lymphomas are grouped by the way their cells look under a microscope. They may be indolent (slow-growing) or aggressive (fast-growing). AIDS-related lymphoma is usually aggressive. There are three main types of AIDS-related lymphoma:
- Diffuse large B-cell lymphoma.
- B-cell immunoblastic lymphoma.
- Small non-cleaved cell lymphoma.
Possible signs of AIDS-related lymphoma include weight loss, fever, and night sweats.
These and other symptoms may be caused by AIDS-related lymphoma. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:
- Weight loss or fever for no known reason.
- Night sweats.
- Painless, swollen lymph nodes in the neck, chest, underarm, or groin.
- A feeling of fullness below the ribs.
Tests that examine the body and lymph system are used to help detect (find) and diagnose AIDS-related lymphoma.
The following tests and procedures may be used:
- Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
- The number of red blood cells, white blood cells, and platelets.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the sample made up of red blood cells.
- Lymph node biopsy: The removal of all or part of a lymph node. A pathologist views the tissue under a microscope to look for cancer cells. One of the following types of biopsies may be done:
- Excisional biopsy: The removal of an entire lymph node.
- Incisional biopsy or core biopsy: The removal of part of a lymph node.
- Needle biopsy or fine-needle aspiration: The removal of a sample of tissue from a lymph node with a needle.
- Bone marrow biopsy: The removal of a small piece of bone and bone marrow by inserting a needle into the hipbone or breastbone. A pathologist views both the bone and bone marrow samples under a microscope to look for signs of cancer.
- HIV test: A test to measure the level of HIV antibodies in a sample of blood. Antibodies are made by the body when it is invaded by a foreign substance. A high level of HIV antibodies may mean the body has been infected with HIV.
- Epstein-Barr virus (EBV) test: A test to measure the level of EBV antibodies in a sample of blood, tissue, or cerebrospinal fluid (CSF). Antibodies are made by the body when it is invaded by a foreign substance. A high level of EBV antibodies may mean the body has been infected with EBV.
- Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
- The stage of the cancer.
- The number of CD4 lymphocytes (a type of white blood cell) in the blood.
- Whether the patient has ever had AIDS-related infections.
- The patient's ability to carry out regular daily activities.
Stages of AIDS-Related Lymphoma
After AIDS-related lymphoma has been diagnosed, tests are done to find out if cancer cells have spread within the lymph system or to other parts of the body.
The process used to find out if cancer cells have spread within the lymph system or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment, but AIDS-related lymphoma is usually advanced when it is diagnosed. The following tests and procedures may be used in the staging process:
- CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radionuclide glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. A substance called gadolinium is injected into the patient through a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- Bone marrow biopsy: The removal of a small piece of bone and bone marrow by inserting a needle into the hipbone or breastbone. A pathologist views both the bone and the bone marrow samples under a microscope to look for signs of cancer.
- Lumbar puncture: A procedure used to collect cerebrospinal fluid from the spinal column. This is done by placing a needle into the spinal column. This procedure is also called an LP or spinal tap.
- Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it. The blood sample will be checked for the level of LDH (lactate dehydrogenase).
Stages of AIDS-related lymphoma may include E and S.
The following stages are used for AIDS-related lymphoma:
Stage I AIDS-related lymphoma is divided into stage I and stage IE.
- Stage I: Cancer is found in one lymph node group.
- Stage IE: Cancer is found in an area or organ other than the lymph nodes.
Stage II AIDS-related lymphoma is divided into stage II and stage IIE.
- Stage II: Cancer is found in two or more lymph node groups on the same side of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).
- Stage IIE: Cancer is found in an area or organ other than the lymph nodes and in lymph nodes near that area or organ, and may have spread to other lymph node groups on the same side of the diaphragm.
Stage III AIDS-related lymphoma is divided into stage III, stage IIIE, stage IIIS, and stage IIIS+E.
- Stage III: Cancer is found in lymph node groups on both sides of the diaphragm (the thin muscle below the lungs that helps breathing and separates the chest from the abdomen).
- Stage IIIE: Cancer is found in lymph node groups on both sides of the diaphragm and in an area or organ other than the lymph nodes.
- Stage IIIS: Cancer is found in lymph node groups on both sides of the diaphragm and in the spleen.
- Stage IIIS+E: Cancer is found in lymph node groups on both sides of the diaphragm, in an area or organ other than the lymph nodes, and in the spleen.
In stage IV AIDS-related lymphoma, the cancer either:
- is found throughout one or more organs other than the lymph nodes and may be in lymph nodes near those organs; or
- is found in one organ other than the lymph nodes and has spread to lymph nodes far away from that organ.
Patients who are infected with the Epstein-Barr virus or whose AIDS-related lymphoma affects the bone marrow have an increased risk of the cancer spreading to the central nervous system (CNS).
For treatment, AIDS-related lymphomas are grouped based on where they started in the body, as follows:
Lymphoma that starts in lymph nodes or other organs of the lymph system is called peripheral/systemic lymphoma. The lymphoma may spread throughout the body, including to the brain or bone marrow.
Primary CNS lymphoma
Primary CNS lymphoma starts in the central nervous system (brain and spinal cord). Lymphoma that starts somewhere else in the body and spreads to the central nervous system is not primary CNS lymphoma.
There are different types of treatment for patients with AIDS-related lymphoma.
Different types of treatment are available for patients with AIDS-related lymphoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Treatment of AIDS-related lymphoma combines treatment of the lymphoma with treatment for AIDS.
Patients with AIDS have weakened immune systems and treatment can cause further damage. For this reason, patients who have AIDS-related lymphoma are usually treated with lower doses of drugs than lymphoma patients who do not have AIDS.
Highly-active antiretroviral therapy (HAART) is used to slow progression of HIV (which is a retrovirus). Treatment with HAART may allow some patients to safely receive anticancer drugs in standard or higher doses. Medicine to prevent and treat infections, which can be serious, is also used.
AIDS-related lymphoma usually grows faster than lymphoma that is not AIDS-related and it is more likely to spread to other parts of the body. In general, AIDS-related lymphoma is harder to treat.
Three types of standard treatment are used:
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column (intrathecal chemotherapy), an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is treatment using more than one anticancer drug. The way the chemotherapy is given depends on the type and stage of the cancer being treated.
Intrathecal chemotherapy may be used in patients who are more likely to have lymphoma in the central nervous system (CNS).
Colony-stimulating factors are sometimes given together with chemotherapy. This helps lessen the side effects chemotherapy may have on the bone marrow.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
High-dose chemotherapy with stem cell transplant
High-dose chemotherapy with stem cell transplant is a method of giving high doses of chemotherapy and replacing blood-forming cells destroyed by the cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells.
New types of treatment are being tested in clinical trials. These include the following:
Monoclonal antibody therapy
Monoclonal antibody therapy is a cancer treatment that uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. These may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells.
AIDS-Related Peripheral/Systemic Lymphoma
There is no standard treatment plan for AIDS-related peripheral/systemic lymphoma. Treatment is adjusted for each patient and is usually one or more of the following:
- Combination chemotherapy.
- High-dose chemotherapy and stem cell transplant.
- A clinical trial of monoclonal antibodies.
- A clinical trial of different treatment combinations.
AIDS-Related Primary Central Nervous System Lymphoma
Treatment of AIDS-related primary central nervous system lymphoma is usually radiation therapy.
Source: National Cancer Institute