Lymphoma is a group of blood cell tumors that begin in cells of the body's immune system. In the United States, about 79,990* new cases of lymphoma are diagnosed every year. In lymphoma, cancer cells are found in the lymphatic system, which is comprised of the bone marrow, lymph nodes, spleen, stomach, intestines and skin. Because lymph tissues are present in many parts of the body, lymphoma can start almost anywhere.
Normal lymph nodes are tiny, beanlike structures that trap cells containing poisons and waste materials. They also serve as a reservoir of cells that supply microorganism-fighting antibodies. Tubelike vessels carrying milk-colored fluid called lymph connect lymph nodes to each other. Lymph allows white blood cells (lymphocytes) to circulate. When white blood cells multiply abnormally, they cause masses to form and lymph nodes become enlarged. Some lymphomas may affect the bone marrow and interfere with its making of blood cells. The result is anemia, or low red blood cell count.
*American Cancer Society, Cancer Facts & Figures 2014
Classification of Lymphomas
Lymphomas are graded as low, intermediate and high depending on the kind of lymphoma cells present and how they affect lymph nodes and chromosomes. Some lymphomas grow faster and require specific treatment. Classifying them is complex because many kinds of lymphocyte cells can be involved.
These grow so slowly that patients can live for many years mostly without symptoms, although some may experience pain from an enlarged lymph gland. After five to 10 years, low-grade disorders begin to progress rapidly to become aggressive or high-grade and produce more severe symptoms.
This type progresses fairly rapidly without treatment. With treatment, remission can be induced in between 50 to 75 percent of cases. Initial treatment has been so successful that people who stay in remission for three years after diagnosis are often considered cured. Stage I disorders are treated with radiotherapy.
Without treatment, these can progress rapidly regardless of stage. They are treated aggressively. With treatment, between 50 to 75 percent of patients enter remission. Those who stay in remission one year can look forward to a life free from recurrence. Treatment consists of intensive combination chemotherapy, which is sometimes supplemented with radiation therapy. Drug regimens used are determined by a number of factors, the most important being tissue study.
Types of Lymphomas
Based on the course of disease and the kind of lymphocytes affected, lymphomas are divided into two types: Hodgkin disease and non-Hodgkin lymphoma.
About 75 percent of those diagnosed with Hodgkin disease recover fully. About 90 percent of all people diagnosed with early-stage illness and more than 50 percent of those with more advanced stage are now living longer than 10 years with no signs of the disease coming back. The stage of the disease at diagnosis is critical in planning treatments. Sometimes giving the patient aggressive chemotherapy and then introducing young cells from the bone marrow (bone marrow transplantation) may increase chances of the patient living longer. A bone marrow transplant should be considered for every patient whose disease comes back after undergoing chemotherapy.
In the past 10 years, this disease has become easier to treat as more procedures are found to be effective. Overall, 50 to 60 percent of patients with non-Hodgkin lymphoma now live five years or longer without a recurrence. While a number of factors determine the best treatment for these disorders, the most significant is tissue classification followed by determination of the disease's stage.
In most cases, patients consult their doctors if they have painless swelling in the neck, armpits, groin or abdomen. Sometimes the swelling, or the tumor, occurs in other organs such as the skin or stomach (extranodal lymphoma), either as a first symptom or a sign appearing later in the disease.
Like most cancers, lymphoma is best treated when found early.
- Loss of appetite
- Loss of weight, nausea, vomiting, indigestion or pain in the abdomen
- A feeling of bloating
- Itching, bone pain, headaches, constant coughing and abnormal pressure and congestion in the face, neck and upper chest
- Fatigue and flu-like body aches
- Fatigue resulting from anemia
- Night sweats, recurring high-grade fever or constant low-grade fever
Causes and Risk Factors
Cancers in the mouth and oropharnyx often spread to the lymph nodes in the neck. There are 600 lymph nodes in the body. Approximately 200 nodes are in the head and neck.
The lymphatic channels are similar to blood vessels, but the channels transport lymph instead of blood. Lymph is a liquid that carries white blood cells throughout the body to fight infection. Lymph can also transport cancer cells to other parts of the body. The lymph nodes act like filters and trap infected material. The infected material can make the nodes enlarge.
The cause of lymphoma is still not known, but it is not considered hereditary. Most lymphomas occur between the ages of 40 and 70 years. Hodgkin disease, considered the most curable form of lymphoma, often occurs in young adults or the elderly. Possible triggers for lymphoma include:
- Genetic factors
- Certain infections or environmental factors.
- Exposure to herbicides and high doses of radiation (including aggressive radiation therapy).
- Certain viruses (human retroviruses like HTLV-1 and to some extent, the Epstein-Barr virus are also suspected).
- AIDS (acquired immunodeficiency syndrome). These patients require specialized treatment.
- Abnormalities in the genetic materials called chromosomes and the body's immune response.
Although the disease has been reported in patients who live or work physically close to each other (clustering), no evidence exists that indicate the disease is infectious.
In reaching a diagnosis of lymphoma, doctors may do the following:
- Take the patient's medical history
- Conduct a thorough physical examination to detect an enlarged lymph node, liver and/or spleen
- Order blood tests to check kidney and liver functioning
- Do a biopsy by removing a small amount of tissue from the suspected area and examining it to see the type of lymphoma present
Radiotherapy is the preferred treatment for patients with stage I or II lymphomas because it successfully induces long-term remissions and even cures in many cases. For treatment of stage III or IV low-grade disorders, one school of thought is to start intensive therapy right after diagnosis — whether a patient has symptoms or not — to achieve and maintain complete remission. Treatment usually consists of high-dose radiotherapy, chemotherapy or a combination of both. Intensive treatment involves risk, but recent studies suggest that such treatment may induce high rates of remission.
Bone marrow transplant is being studied as a treatment option for low-grade lymphoma.