Definition of Non-Hodgkin Lymphoma
The non-Hodgkin lymphomas (NHLs) are a diverse group of blood cancers that include any kind of lymphoma except Hodgkin’s lymphomas. Types of NHL vary significantly in their severity, from indolent to very aggressive.
Lymphomas are types of cancer derived from lymphocytes, a type of white blood cell. Lymphomas are treated by combinations of chemotherapy, monoclonal antibodies, immunotherapy, radiation, and hematopoietic stem cell transplantation.
Cause of Non-Hodgkin Lymphoma
The many different forms of lymphoma likely have different causes. These possible causes and associations with at least some forms of NHL include:
- Infectious agents like Epstein-Barr virus, Human T-cell leukemia virus, Helicobacter pylori, HHV-8, and HIV infection.
- Chemicals, like diphenylhydantoin, dioxin, and phenoxyherbicides.
- Medical treatments like radiation therapy and chemotherapy
- Genetic diseases, like Klinefelter’s syndrome, Chédiak-Higashi syndrome, ataxia telangiectasia syndrome
- Autoimmune diseases, like Sjögren’s syndrome, celiac sprue, rheumatoid arthritis, and systemic lupus erythematosus.
Some studies have shown an association between non-Hodgkin lymphoma and exposure to polychlorinated biphenyls (PCBs), a persistent organic pollutant now found throughout the natural environment. However, other similar studies have found no such link. Studies of PCB workers have uniformally shown no statistically significant increased rates of deaths from non-Hodgkin Lymphoma.
Signs and Symptoms of Non-Hodgkin Lymphoma
Non-Hodgkin’s lymphoma symptoms may include:
- Swollen lymph nodes in your neck, armpits or groin
- Bloody stool or vomit
- Abdominal pain or swelling
- Chest pain, coughing or trouble breathing
- Visual problems
- Night sweats
- Balance problems
- Weight loss
Risk Factors for Non-Hodgkin Lymphoma
Researchers have found several factors that may affect a person’s chance of getting non-Hodgkin lymphoma. There are many types of lymphoma, and some of these factors have been linked only to certain types.
Non-Hodgkin’s lymphoma can occur at any age, but the risk increases with age. It’s most common in people in their 60s or older.
Overall, the risk of non-Hodgkin lymphoma is higher in men than in women, but there are certain types of non-Hodgkin lymphoma that are more common in women.
Exposure to certain chemicals
Certain chemicals such as benzene and certain herbicides and insecticides (weed- and insect-killing substances) may be linked with an increased risk of non-Hodgkin lymphoma. Research to clarify these possible links is still in progress.
Some chemotherapy drugs used to treat other cancers may increase the risk of developing non-Hodgkin lymphoma many years later. For example, patients who have been treated for Hodgkin disease have an increased risk of later developing non-Hodgkin lymphoma. But it’s not totally clear if this is related to the disease itself or if it is an effect of the treatment.
Patients treated with radiation therapy for some other cancers, such as Hodgkin disease, have a slightly increased risk of developing non-Hodgkin lymphoma later in life. This risk is greater for patients treated with both radiation therapy and chemotherapy.
Medications that suppress your immune system
Non-Hodgkin lymphoma is most common among those who have animpaired immune system, an autoimmune disease, or HIV or AIDS. It also occurs among those who take immunosuppressant medicines, such as medicines following an organ transplant.
Some types of infections may raise the risk of non-Hodgkin lymphoma in different ways. Viruses linked to increased non-Hodgkin’s lymphoma risk include HIV and Epstein-Barr virus. Bacteria linked to an increased risk of non-Hodgkin’s lymphoma include the ulcer-causing Helicobacter pylori.
Body weight and diet
Some studies have suggested that being overweight or obese may increase your risk of non-Hodgkin lymphoma. Other studies have suggested that a diet high in fat and meats may raise your risk. More research is needed to confirm these findings. In any event, maintaining a healthy weight and eating a healthy diet have many known health benefits outside of the possible effect on lymphoma risk.
Diagnosis of Non-Hodgkin Lymphoma
- Physical examination. Your doctor may conduct a physical exam to determine the size and condition of your lymph nodes and to find out whether your liver and spleen are enlarged. In most cases, swollen lymph nodes are signs of infection (rather then lymphoma), and your doctor will try to establish if you have any other signs of infection and what the source of the infection could be.
- Blood tests. Blood tests measure the amounts of certain types of cells and chemicals in the blood. They are not used to diagnose lymphoma, but they can sometimes help determine how advanced the lymphoma is.
- Imaging tests. A chest X-ray or CT scan of the chest or neck might help detect the presence of tumors or more enlarged lymph nodes. Positron emission tomography (PET) scanning is a newer modality to help detect NHL.
- Lab tests on biopsy samples to diagnose and classify lymphoma. Analyzing lymph node tissue in a lab may reveal whether you have non-Hodgkin’s lymphoma and, if so, which type.
- Looking for cancer cells in your bone marrow. A bone marrow biopsy can establish the spread of the disease. This involves the insertion of a needle into bone to obtain bone marrow. In adults, the most common site for this biopsy is the pelvic bone.
Prevention from Non-Hodgkin Lymphoma
There is no known way to prevent non-Hodgkin’s lymphoma (NHL). Most people with NHL do not have known risk factors.
Treatment of Non-Hodgkin Lymphoma
Your doctor determines your treatment options based on the type and stage of your lymphoma, your age, and your overall health.
Treatment isn’t always necessary
If you have a slow-growing non-Hodgkin’s lymphoma without symptoms, you may not require treatment for the cancer right away. You will be watched closely by your health-care team. These cancers might not require treatment for years, although close follow-up is necessary. If the indolent lymphoma produces symptoms, therapy will usually consist of chemotherapy and biological therapy. Stage I and II often requireradiation therapy.
If treatment is required, there are several options that are utilized alone or in combination:
Chemotherapy. This is a drug treatment either as an injection or oral form that kills cancer cells. Chemotherapy drugs can be given alone, in combination with other chemotherapy drugs or combined with other treatments. Chemotherapy also harms normal cells that divide rapidly. This can lead to hair loss, GI symptoms, and difficulty with your immune system.
Radiation therapy. Radiation therapy uses high-powered energy beams, such as X-rays, to kill cancerous cells and shrink tumors. During radiation therapy, you’re positioned on a table and a large machine directs radiation at precise points on your body. This modality can be used alone or in conjunction with other therapies. Side effects usually depend on the type and dosage of the therapy as well as the area undergoing radiation therapy.
Stem cell transplant. A stem cell transplant is a procedure that allows you to receive higher doses of chemotherapy or radiation with the goal of killing the lymphoma cells that may not be killed with standard doses. Before a stem cell transplant, healthy stem cells — those capable of producing new blood cells — are taken from your blood or bone marrow and frozen. These healthy stem cells can also come from a related or unrelated donor. After the therapy, healthy stem cells (that were either taken from you before the therapy or from a donor) are injected to form a new immune system.
Medications that enhance your immune system’s ability to fight cancer. Biological drugs help your body’s immune system fight cancer. Rituximab (Rituxan) is such a drug used in the treatment of B cell lymphoma.
Radio immunotherapy medications: Radioimmunotherapy drugs are made of monoclonal antibodies that carry radioactive isotopes. This allows the antibody to attach to cancer cells and deliver radiation directly to the cells. Two radioimmunotherapy drugs — ibritumomab (Zevalin) and tositumomab (Bexxar) — are FDA approved for use in people with lymphoma.