Non-Hodgkin's lymphoma is cancer of a type of white blood cell (lymphocyte) in the lymphatic system. This system, comprised of the lymph nodes, spleen, and bone marrow, drains fluid from tissue and returns it to the blood. It plays an important role in the body's defense against infection.
What is going on in the body?
Non-Hodgkin's lymphoma starts either in the lymph nodes, the spleen, the bone marrow, or other less common lymph tissues. Lymph nodes are small, round glands found all over the body. Lymphoma cells grow and cause lymph nodes and internal organs to enlarge.
These cells also infiltrate and crowd out the bone marrow. They can invade any other part of the body, including the brain, lungs, kidneys, skin, bone, intestines, liver, spleen, or the heart. Lymphomas can also cause the immune system to malfuncation, resulting in unusual infections.
Autoimmune disorders - those in which the body's immune system attacks itself - are common in people with non-Hodgkin's lymphoma. They may lead to kidney failure, anemia, blood clots, bleeding, arthritis, or nerve damage.
What are the causes and risks of the disease?
Lymphoma occurs when the genes of a white blood cell change enough that the cell grows uncontrollably. How this occurs is an important part of cancer research. Many of the genes that become abnormal and control this cell growth have been described. The exact process, as well as why some people develop lymphoma and others do not, remains unsolved.
Some of the risk factors for non-Hodgkin's lymphoma are:
- exposure to radiation or certain viruses
- inherited or acquired immunodeficiency disorders, such as AIDS
- medicines, such as corticosteroids and medicines given after organ transplants
- treatments that suppress the immune system, such as chemotherapy
Some autoimmune disorders may increase the risk of non-Hodgkin's lymphoma. Tobacco use does not seem to be a strong risk factor. There is controversy over whether some pesticides or herbicides can cause lymphoma. Non-Hodgkin's lymphoma occurs in all age groups and both genders. Some subtypes are more common in elderly people, and others are more common in young people.
What can be done to prevent the disease?
It's important to avoid radiation and toxins in the environment. These toxins include pesticides, insecticides, and solvents. There is no proof that the diet is important in preventing lymphoma. People whose medical problems put them at risk of developing lymphoma should see a healthcare provider regularly.
How is the disease diagnosed?
Diagnosis of non-Hodgkin's lymphoma begins with a medical history and physical exam. Once suspected, the diagnosis is confirmed by the microscopic examination of tissue samples, usually from a lymph node or from a bone marrow biopsy. Blood samples are taken so that immune studies can be done on white blood cells. Some, but not all, lymphomas cause higher levels of white cells in the blood.
Lymphomas are classified into different subtypes based on their characteristics. This classification of lymphomas continues to evolve as knowledge of the disease advances. As with Hodgkin's disease, it is important to determine the stage of a non-Hodgkin's lymphoma - that is, to what parts of the body, if any, the disease has spread.
Tests used in staging include:
- blood tumor marker tests
- bone marrow biopsy, usually on both sides of the pelvis
- chest X-ray
- a complete blood count, or CBC
- CT scans of the chest, abdomen, and pelvis
- kidney function tests
- LDH and isoenzymes blood test, which measures tissue damage
- liver function tests
Lymphoma stages are classified as I, II, III, and IV. This classification scheme is like the one for Hodgkin's lymphoma.
- Stage I is limited to one lymph node area in the body.
- Stage II involves two lymph node areas that are next to each other.
- Stage III involves lymph node areas on both sides of the diaphragm, the muscle that separates the chest from the abdomen.
- Stage IV involves widespread disease that affects other organs, such as the liver, spleen, bone marrow, bone, lung, central nervous system, and skin.
Staging does not predict treatment outcomes as it does in Hodgkin's disease. In non-Hodgkin's lymphoma, a better predictor is the type of tissue involved. Special laboratory testing called immune analysis can help predict the outcome of lymphoma. This analysis looks at cell proteins and gene abnormalities. However, it is not always helpful in determining which treatment to use.
Long Term Effects
What are the long-term effects of the disease?
Long-term effects of non-Hodgkin's lymphoma depend on the histology, or cell type. Some people are completely cured, while others need periodic treatment when the cancer recurs. An individual with high-grade lymphoma may die quickly.
What are the risks to others?
Non-Hodgkin's lymphoma is not contagious and poses no risk to others.
What are the treatments for the disease?
Because lymphoma tends to be a total-body or systemic disease chemotherapy is the mainstay of treatment. The exact medicines, doses, duration of treatment, and combination with radiation therapy depend on the type of lymphoma. High and sometimes intermediate-grade lymphomas are treated with intensive high-dose intravenous (IV) chemotherapy.
Methotrexate, vincristine, vinblastine, etoposide (VP-16), and many other medicines are used. They are given in cycles for several weeks to several months. People are usually treated as outpatients unless other medical problems arise. Low-grade lymphomas are treated when problems occur.
The problems usually result from long-term treatment with immune therapy or low-dose chemotherapy medicines, such as cladribine (2-cda, i.e., Leustatin) or fludarabine (i.e., Fludara).
It is not known for sure whether this disease can be cured with medical treatment. The problem has been that the disease recurs after treatment, and the recurrence is harder to treat.
Lymphoma may need to be treated with high-dose chemotherapy, total-body or total-lymph node radiation, and bone marrow transplantation. Surgery is sometimes needed, but it is not considered a cure. Surgery can relieve problems caused by lymphoma. These include bowel obstruction, blocked blood vessels, and spinal cord compression.
Radiation therapy is used to ease symptoms and as a potential cure. Early-stage lymphoma limited to one lymph node area can sometimes be cured with radiation alone. But radiation therapy alone does not work well on more advanced lymphomas. Radiation therapy is also used to shrink bothersome lymph nodes or other masses.
Immune therapy is giving a person manufactured proteins and other substances often made by a normal immune system. This is a new and evolving kind of treatment. Interferons, interleukins, monoclonal antibodies, immune toxins, or radiolabeled immune proteins may be given.
What are the side effects of the treatments?
- abnormal bleeding
- hair loss
- an increased chance of needing blood transfusions
- lowered blood counts
- mouth and lip sores
- nausea and vomiting
- a risk of infections
- stomach upset
- irritation of the esophagus or intestines
- lymphedema, which occurs when a fluid called lymph builds up and causes swelling of an extremity
- nausea and vomiting
- a risk for other cancers
- skin burning
- temporarily lowered blood counts
These treatments also can cause damage to:
- the bone marrow
- the heart
- the kidneys
- the liver
- the lungs
- peripheral nerves
A combination of radiation and chemotherapy can increase the severity of side effects.
High-dose chemotherapy and bone marrow transplantation are highly toxic and risky treatments. Sometimes the transplanted immune system attacks the person's normal cells and tissue. There can be mild problems with skin rash and diarrhea. Major organ failure can occur, causing death.
What happens after treatment for the disease?
Some low-grade lymphomas are treated only to lessen the symptoms. Treatment is stopped when the benefits do not outweigh the side effects. Some people may need to be treated periodically. Other lymphomas are considered curable. Even some high-grade lymphomas have a 60% to 80% cure rate.
How is the disease monitored?
Because non-Hodgkin's lymphoma can sometimes recurs the healthcare provider will monitor a person for several years by doing:
- bone scans
- bone marrow biopsies
- CT scans
- chemistry blood tests
- complete blood counts
- physical exams
Any new or worsening symptoms should be reported to the healthcare provider.