Non-Hodgkin lymphoma (NHL)
- Is a type of cancer that affects the lymphatic system
- Generally develops in the lymph nodes and lymphatic tissues. In some cases, NHL involves bone marrow and blood.
- Isn't just one disease–it's actually a diverse group of blood cancers that share a single characteristic in how they develop
- NHL has many different subtypes which are either indolent (slow growing) or aggressive (fast growing).
Click here to access NHL statistics.
What You Should Know
- Hematologists and oncologists are specialists who treat people who have NHL or other types of blood cancer.
- Treatment for people who have NHL may include drug therapy and radiation therapy.
- It's important to know your NHL subtype
What You Should Do
- Seek treatment in a cancer center where doctors are experienced treating patients with lymphoma.
- Talk with your doctor about your diagnostic tests and what the results mean.
- Be sure you know your NHL subtype - different subtypes have different treatments.
How Does NHL Develop?
NHL usually starts with an abnormal change in a white cell in a lymph node or lymphoid tissue called a lymphocyte. It can start in one of three major types of lymphocytes:
- B lymphocytes (B cells), which produce antibodies to help combat infections
- T lymphocytes (T cells), which have several functions, including helping B lymphocytes make antibodies
- Natural killer (NK) cells, which attack virus-infected cells or tumor cells
About 85 percent of NHL cases start in the B cells. Your doctor plans your treatment according to the type of cell your NHL developed in.
The abnormal lymphocyte grows out of control and produces more abnormal cells like it.
- These abnormal lymphocytes (lymphoma cells) accumulate and form masses (tumors). If NHL isn't treated, the cancerous cells crowd out normal white cells, and the immune system can't guard against infection effectively.
- NHL that develops in or spreads to other areas of the body where lymphoid tissue is found, such as the spleen, digestive tract and bone marrow, is called primary extranodal lymphoma.
- NHL is classified into more than 30 different subtypes. Doctors classify the NHL subtypes into categories that describe how rapidly or slowly the disease is progressing:
- Aggressive NHL
- Indolent (slow-growing) NHL
The exact cause of NHL is not known but there are risk factors that may increase a person’s likelihood of developing the disease.
Immune suppression is one of the most clearly established risk factors for NHL. People with autoimmune disease, acquired immunodeficiencies including human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS), and organ transplant recipients have an elevated risk for NHL. In addition, factors that suppress the immune system, such as chemical exposures or treatments for autoimmune diseases, may contribute to the development of NHL.
Farming communities have a higher incidence of NHL. Some studies suggest that specific ingredients in herbicides and pesticides such as organochlorine, organophosphate and phenoxy acid compounds, are linked to lymphoma. The number of lymphoma cases caused by such exposures has not been determined. More studies are needed to understand these associations.
Exposure to certain viruses and bacteria is associated with NHL. It is thought that infection with either a virus or a bacterium can lead to intense lymphoid cell proliferation, increasing the probability of a cancer-causing event in a cell. Here are some examples:
- Epstein-Barr virus (EBV) infection
- Human T-cell lymphotropic virus-1 (HTLV-1)
- Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS)
- The bacterium Helicobacter Pylori (H Pylori)
- Hepatitis C
Other conditions, such as Sjögren syndrome, Wiskott-Aldrich syndrome and Klinefelter syndrome can predispose individuals to later development of NHL
Source: Non-Hodgkin Lymphoma. Reviewed by Sonali M. Smith, MD