What is Non-Hodgkin Lymphoma?
Non-Hodgkin lymphoma (NHL) is a type of cancer that begins in the lymphatic system, a critical part of the body's immune system. The lymphatic system includes lymph nodes, the spleen, bone marrow, and lymphatic vessels that help fight infection and disease.
Non-Hodgkin lymphoma develops when certain white blood cells, called lymphocytes, grow abnormally and multiply out of control. These cancerous cells can accumulate in lymph nodes and other organs throughout the body. Unlike Hodgkin lymphoma, NHL does not contain a specific type of abnormal cell called a Reed-Sternberg cell.
Non-Hodgkin lymphoma is one of the most common blood cancers in the United States. There are more than 70 different subtypes of NHL, ranging from slow-growing (indolent) forms that may require little immediate treatment to aggressive forms that require prompt medical care. Common subtypes include diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and marginal zone lymphoma.
Because NHL can affect many different parts of the body, symptoms and treatment options vary depending on the type, location, and stage of the disease. Advances in targeted therapies and immunotherapies have significantly improved outcomes for many people diagnosed with non-Hodgkin lymphoma.
Risk Factors
Several factors may increase the risk of developing non-Hodgkin lymphoma:
- Age: The risk of NHL increases with age, and most cases occur in people over age 60. However, some types of NHL can occur in children and younger adults.
- Sex: Certain types of NHL are more common in men than in women.
- Weakened Immune System: People with weakened immune systems, including organ transplant recipients and individuals with immune disorders, have a higher risk of developing NHL.
- Autoimmune Diseases: Conditions such as rheumatoid arthritis, lupus, Sjögren's syndrome, and celiac disease have been associated with an increased risk of lymphoma.
- Certain Infections:
- Epstein-Barr virus (EBV)
- Human immunodeficiency virus (HIV)
- Hepatitis C virus
- Human T-cell leukemia/lymphoma virus (HTLV-1)
- Helicobacter pylori infection
- Family History: Having a close relative with lymphoma may slightly increase a person's risk.
- Exposure to Chemicals: Long-term exposure to certain pesticides, herbicides, solvents, and industrial chemicals may increase lymphoma risk.
- Previous Cancer Treatment: Some people who have received chemotherapy or radiation therapy for other cancers may have a slightly increased risk of developing NHL later in life.
- Obesity: Research suggests that excess body weight may contribute to a higher risk of several cancers, including some types of lymphoma.
While these factors can increase the risk of developing non-Hodgkin lymphoma, having one or more risk factors does not mean someone will develop the disease. Regular medical care and discussing any concerns with a healthcare provider can help support early detection and treatment.