Environmental Public Health Tracking: Non-Hodgkin Lymphoma Data

Non-Hodgkin's lymphomas are a group of cancers that start in lymphoid tissue. Lymphoid tissue, or lymph, is the fluid that circulates in the lymphatic system.  Lymph helps rid the body of toxins and waste.

The causes of Non-Hodgkin lymphomas are mostly unknown. Specific viruses, immune deficiency, and specific autoimmune conditions can increase risk for non-Hodgkin lymphoma. More research is needed, but some environmental issues are also being investigated.

Other risk factors that might increase risk for non-Hodgkin lymphoma include:

• Age. Getting older is a strong risk factor for this disease; most cases occur in people aged 60 years or older.
• Exposure to certain chemicals. Some studies have suggested that chemicals such as benzene and certain herbicides and insecticides may be linked with an increased risk for Non-Hodgkin's lymphomas. More research is needed to determine the validity of these studies.
• Treatment with chemotherapy drugs. Some chemotherapy drugs used to treat cancers can increase the risk for Non-Hodgkin lymphomas many years later.
• Weakened immune systems. People with weakened immune systems are at increased risk for Non-Hodgkin lymphomas. Sometimes children are born with a dysfunctional immune system. These children have a higher risk for developing Non-Hodgkin lymphomas in childhood or as young adults.
• Autoimmune diseases. Some autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus (SLE) have been linked to an increased risk for Non-Hodgkin lymphomas.
• Certain Infections. HIV infection (also known as the AIDS virus), HTLV-1 (a virus in the same family as HIV), Epstein-Barr virus (mainly in patients infected with HIV), and Helicobacter pylori (a type of bacteria that causes stomach ulcers) may increase risk for non-Hodgkin lymphoma.
• Body Weight and Diet. Being very overweight or obese might increase the risk for Non-Hodgkin lymphomas. Some studies have suggested that a diet high in vegetables may lower the risk for Non-Hodgkin lymphomas, but more research is needed to confirm this.
• Radiation Exposure.
  • Atomic bomb explosions. Very high levels of radiation have been caused by atomic bomb explosions (such as those in Japan during World War II). People, especially children, who survive atomic bomb explosions are at increased risk of leukemia.
  • Radiation therapy. Another source of exposure to high levels of radiation is medical treatment for cancer and other conditions. Radiation therapy can increase the risk of leukemia.
  • Diagnostic x-rays. Dental x-rays and other diagnostic x-rays (such as CT scans) expose people to much lower levels of radiation. It's not known yet whether this low level of radiation to children or adults is linked to leukemia. Researchers are studying whether having many x-rays may increase the risk of leukemia. They are also studying whether CT scans during childhood are linked with increased risk of developing leukemia.

The best way to minimize risk for non-Hodgkin lymphoma is to reduce exposure to known risk factors, such as reducing the spread of HIV. HIV is spread through sexual contact or sharing contaminated needles by injection drug users.

Researchers are exploring the relationship between some infectious diseases and lymphoma. It is possible that methods to prevent non-Hodgkin lymphomas may be discovered in the near future.

• National Cancer Institute – Non-Hodgkin Lymphoma
• American Cancer Society – Non-Hodgkin Lymphoma