It's one of the fastest rising cancers in the United States.¹ It's the sixth most common cancer among males,² the fifth most common cancer among females² and accounts for about 6 percent of childhood cancers.³   In 2008, over 66,000 Americans will be diagnosed with it, and over 19,000 will die from it.⁴ It claimed the lives of Jacqueline Kennedy Onassis and King Hussein of Jordan.  It's non-Hodgkin lymphoma (NFL).

Like all cancers, lymphoma causes cells to abnormally reproduce, eventually causing tumors to grow.  There are both similarities and differences between the two main categories of lymphoma – Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL).  Both originate in a type of white blood cell known as a lymphocyte, which is found within the lymph nodes or lymphoid tissue within other organs. But, they grow and spread in different ways, and the treatments that work best are different for each.  Doctors distinguish between them by looking for one type of cell (the Reed Sternberg cell) that's found only in Hodgkin lymphoma. 

The mysteries of NHL are just beginning to be unraveled.  Among it's many puzzles:

• What makes a lymphocyte transform into a lymphoma cell?
• How does it relate to other lymphomas and leukemias?
• What are the risk factors?
• Why is its incidence increasing while many other cancers are trending down?
• Why does it take a more aggressive form in some people than in others?
• Why does it manifest differently in children than in adults?

Cause can be established only in a small minority of NHL cases.  Despite multiple studies, information about risk factors remains inconclusive.  Researchers have found a number of associations with NHL that warrant further study including:

• Certain chemical exposures, such as pesticides (insect killers) and herbicides (weed killers)
• Some bacteria and viruses, such as the HIV, Hepatitis C and Epstein-Barr viruses
• Previous chemotherapy or radiation therapy
• Conditions which weaken the immune system
• Constant immune system reactions, such as those triggered by allergies
• Certain genetic and chromosomal abnormalities
• Long duration and early use of permanent dark hair dyes
• Nitrates in drinking water from runoff following the use of nitrogen fertilizer by farms
• Long-term illegal use of narcotic drugs

An individual's first inkling that something is wrong is usually a painless swelling of the lymph nodes, usually in the neck, underarm, groin or in the abdomen.  Of course, nodes can swell as a result of a simple infection, but in that instance they're usually tender.  Other symptoms may include:

• Unexplained fever
• Excessive sweating and night sweats
• Excessive fatigue
• Unintentional weight loss
• Severe itching
• Recurring infections
• And more, depending on the location and spread of the cancer.  These may include:
• Coughing or shortness of breath if the windpipe is involved
• Stomach pain, swelling or nausea
• Bone pain
• Headaches, problems concentrating, seizures

There's no screening test for NHL and diagnosis is challenging.  See Key Point 1 for more information about diagnosis. 

There are many subtypes of NHL.  Experts disagree on the actual number but most put it in a range of 10 to 30.  The distinction between types matters.  Each is treated differently and prognosis varies greatly.  Staging is important as well, though less so than type for NHL.  See Key Point 2 for more information about treatment. 

Learn more about non-Hodgkin lymphoma:

Key Point 1:  Lymphoma is a cancer of the lymph glands.  Classification tells you what kind you have.  Staging tells you where it is.  Early diagnosis, classification and staging affect treatment and prognosis.  

Key Point 2:  The treatments for non-Hodgkin lymphoma are effective and improving.  People can live long, productive lives with correct treatment.