Non-Hodgkin lymphoma: Symptoms, diagnosis and treatment
What is non-Hodgkin lymphoma?
Lymphoma is a cancer of the lymphatic system, an important part of the body's immune system.
Around 80% of all lymphomas diagnosed in the UK are non-Hodgkin’s lymphoma. The risk of developing non-Hodgkin lymphoma increases as you get older. You are also more likely to get this disease if you are male or white.
The most common symptom of non-Hodgkin lymphoma is a swelling in a lymph node, often in the neck, armpit or groin. These swellings are not painful.
The lymphatic system - whose largest organ is the spleen - is a network of nodes (knots of tissue) connected by vessels. Together, they drain fluid and waste products from all of the organs and structures in your body. The lymph nodes act as tiny filters, straining out invading organisms and cancerous cells.
Lymphocytes, a type of white blood cell that attacks infectious invaders such as bacteria, viruses and fungi, destroy most infections before they can enter the bloodstream. When the lymphatic system is fighting an active infection, you may notice that some of your lymph nodes and tissue in the area of the infection become swollen and tender. This is normal.
Lymphoma occurs when the lymph-node cells or the lymphocytes begin to multiply uncontrollably, producing cancerous cells that have the abnormal capacity to invade other tissues throughout the body. The two main types of lymphoma are Hodgkin and non-Hodgkin. They are classified by certain unique characteristics of the cancer cells.
Non-Hodgkin lymphoma can be further classified into a variety of types based on other cell characteristics, such as size, arrangement, growth patterns and invasiveness. These characteristics also help your doctor to predict the chances of your disease being cured or put into remission.
What causes non-Hodgkin lymphoma?
No one knows exactly what causes non-Hodgkin lymphoma. With most patients, the cause is never identified. Medical conditions that have been linked with an increased risk of non-Hodgkin’s lymphoma include:
- A variety of immune deficiencies present at birth
- Sjögren's syndrome - an immune disorder characterised by unusual dryness of the mucous membranes
- Coeliac disease - which involves difficulty processing certain components of gluten, a protein in grains
- Rheumatoid arthritis (RA)
- Systemic lupus erythematosus (SLE)
- HIV infection
- Exposure to Epstein-Barr virus or human T-cell leukaemia/lymphoma virus (HTLV-1)
- Stomach ulcers due to infection with the bacterium Helicobacter pylori (H. pylori)
Other risk factors for non-Hodgkin lymphoma include:
- Regular exposure to certain chemicals, including arsenic, lead, vinyl chloride, asbestos, insect and weedkillers, as well as a number of chemicals used in industries such as farming, welding and timber
- Exposure to nuclear accidents or explosions
- Organ transplantation and treatment with immunosuppressant drugs to prevent organ rejection
- Chemotherapy or radiotherapy treatment for a previous cancer