Non-Hodgkin lymphoma is not a single disease. A large number of cancers of the immune system are included in this category. Non-Hodgkin lymphomas are classed as either B-cell or T-cell, and may be either aggressive (fast growing) or indolent (slow-growing). Non-Hodgkin lymphoma can occur in any part of the body. It usually first develops in a lymph node. More than 72,000 cases of non-Hodgkin lymphoma are diagnosed in the United States every year.
The reasons why people develop non-Hodgkin lymphoma are imperfectly understood. Risk factors which are known to increase the chances of getting the disease include:
- Weak immune system. This may be the result of heredity or may be caused by immunosuppressant drugs used to reduce the possibility of rejection in organ transplants.
- HIV (human immunodeficiency virus) infection. (It is not necessary for the HIV infection to progress to AIDS to greatly increase the risk of non-Hodgkin lymphoma.)
- Epstein-Barr virus infection.
- Bacterial infection of the stomach.
- Hepatitis C.
The warning signs of non-Hodgkin lymphoma can also be symptoms of other conditions. Most people with these symptoms do not have non-Hodgkin lymphoma. However, people who experience these symptoms for more than two weeks should consult a doctor:
- Swollen but painless lymph nodes, especially noticeable in the neck, armpits or groin.
- Unexplained weight loss.
- Heavy night sweats.
- Trouble breathing.
- Chest pain.
- Constant fatigue.
- Painful or swollen abdomen.
Detection, Diagnosis and Staging
Non-Hodgkin lymphoma is usually detected when patients consult with a doctor about symptoms. Since many other conditions have the same symptoms as non-Hodgkin lymphoma, blood tests and x-rays are used to detect the disease.
When a condition which may be non-Hodgkin lymphoma is detected, a biopsy is performed to diagnose the disease. The biopsy is done by surgically removing all or part a swollen lymph node for microscopic examination by a pathologist.
The pathologist determines the type of non-Hodgkin lymphoma present and whether it is indolent (slow-growing) or aggressive (fast-growing).
Staging of non-Hodgkin lymphoma depends on the location and extent of malignancies.
- Stage I: lymphoma cells are in one group of lymph nodes or one organ only.
- Stage II: lymphoma cells are in more than one group of lymph nodes on the same side of the diaphragm, or in one or more group(s) of lymph nodes and part of one organ on the same side of the diaphragm.
- Stage III: lymphoma cells are found in lymph nodes above and below the diaphragm. Lymphoma cells may also be present in tissue near the lymph nodes.
- Stage IV: lymphoma cells are found in the liver, blood or bone marrow or in several parts of one organ or tissue in addition to being in one or more group(s) of lymph nodes.
- Recurrent: Lymphoma that returns after treatment.
In addition to the staging numbers, non-Hodgkin lymphoma may be classified as type A or B.
- A: The patient has not lost weight or had night sweats or fever.
- B: The patient has had weight loss and night sweats and/or fever.
Diagnostic procedures used to stage non-Hodgkin lymphoma include:
- Biopsy. A hollow needle takes small sample of marrow from a bone. The sample is examined microscopically by a pathologist to determine how many and what kind of cells are present.
- Spinal tap. Fluid is drawn from the spinal column for microscopic analysis by a pathologist.
- MRI. A magnetic resonance imaging scan provides precise images of areas of interest, such as the bone marrow, spinal cord or brain.
- CT. A computed tomography scan with contrast agent provides a precise structural image of swollen lymph nodes.
- PET. A positron emission tomography scan detects unusual metabolic activity at a molecular level to find cancer undetectable by other methods.
- PET-CT. A combined PET and CT scan can simultaneously find microscopic cancers, determine how aggressive they are and locate them precisely.
- Ultrasound. Sound waves reflected off internal tissue create an image in which tumors can be differentiated from healthy tissue.
The appropriate treatment for non-Hodgkin lymphoma depends on the specific type of non-Hodgkin lymphoma, the stage, whether it is slow-growing or aggressive and the age and health of the patient.
Patients with indolent (slow growing) non-Hodgkin lymphoma and who do not have symptoms of the disease which require immediate treatment may choose to postpone treatment. Non-Hodgkin lymphoma may remain stable for years, and in some cases a tumor may actually shrink.
Patients who choose watchful waiting should be examined every three months so treatment can begin immediately if their non-Hodgkin lymphoma grows or if symptoms get worse.
Chemotherapy attacks non-Hodgkin lymphoma with drugs that either kill cancer cells or stop them from dividing or with drugs that prevent the growth of new blood vessels needed to sustain a tumor.
Chemotherapy may be administered orally, intravenously or by injection into the space surrounding the spinal cord.
Non-Hodgkin lymphoma of the stomach may be associated with a bacterial infection. This condition is often treated with antibiotics. When the infection has been cured the non-Hodgkin lymphoma may disappear.
Laboratory-produced monoclonal antibodies bind to non-Hodgkin lymphoma cells. This treatment, also called immunotherapy, increases the body’s natural defenses against the cancer cells.
Radiation therapy attacks cancer cells with X-ray or other radiation beams directed at the tumor or with radioactive solutions or pellets injected or placed inside the body.
- External radiation: IMRT (intensity modulated radiation therapy) shapes the beam of radiation to the contours of the tissue to avoid unnecessarily radiating other areas of the body.
- Systemic radiation: Because non-Hodgkin lymphoma may be found in multiple locations in the body, some patients receive an injection of radioactive material bonded to monoclonal antibodies which bind to malignant cells.