Non-Hodgkin lymphoma (NHL)
What are they?
B and T- cell lymphomas (also known as non-Hodgkin lymphomas) are cancers of the lymphatic system. The lymphatic system forms part of the immune system. It contains specialised white blood cells called lymphocytes that help protect the body from infection and disease. Lymphomas arise when developing B and T-lymphocytes undergo a malignant change, and multiply in an uncontrolled way. These abnormal lymphocytes, called lymphoma cells, form collections of cancer cells called tumours, in lymph nodes (glands) and other parts of the body.
The majority of lymphomas (around 80%) arise in developing B-lymphocytes (B-cell lymphomas). The remainder arise in developing T-lymphocytes (T-cell lymphomas).
How common are they?
Each year in Australia around 3,500 people are diagnosed with type of B-cell or T-cell lymphoma* making them the most common type of blood cancer diagnosed. Overall, they represent the sixth most common type of cancer in men, and the fifth most common type of cancer in women.
Who gets lymphomas?
Lymphomas can occur at any age but they are more common in adults over the age of 50 years, who account for over 70% of all cases. Around 40 children (0-14 years) in Australia are diagnosed with lymphoma each year. Lymphomas occur more frequently in men than in women.
What causes lymphomas?
In most cases the exact cause of lymphomas remains unknown but they are thought to result from damage to one or more of the genes that normally control the development of blood cells. Research is going on all the time into possible causes of this damage and it is thought the alterations in the immune system may play a role in some cases. People with a weakened immune system (immunosuppressed) due to an inherited immune deficiency disease, HIV infection, and drugs taken to prevent rejection of a transplanted organ, all have an increased chance of developing lymphoma. Certain viruses such as the Epstein Barr virus, the virus that causes glandular fever, may be involved, particularly in people who are immunosuppressed. The bacteria helicobacter pylori is associated with a rare type of lymphoma called MALT lymphoma which usually affects the lining of the stomach wall.
What are the symptoms?
Some people don't have any symptoms when they are first diagnosed with lymphoma and the disease is picked up during a routine chest x-ray.
The most common symptom of lymphoma is a firm, usually painless swelling of a lymph node (swollen glands), usually in the neck, under the arms or in the groin.
Other symptoms may include:
- recurrent fevers
- excessive sweating at night
- unintentional weight loss
- persistent fatigue and
- lack of energy
- generalised itching
Sometimes lymphoma starts in the lymph nodes in deeper parts of the body like those found in the abdomen (causing bloating), or the lymph nodes in the chest (causing coughing, discomfort in the chest and difficulty breathing). When it is first diagnosed, it is common for lymphoma to be found in several different sites in the body at once. It can spread to any organ and may involve the spleen, liver, brain and spinal cord (central nervous system) and bone marrow.
How are they diagnosed?
B and T-cell lymphomas are diagnosed by examining cells from an affected lymph node.
How are they treated?
Treatment varies depending the exact type of B or T-cell lymphoma you have, where it has spread in your body and how fast it is likely to grow. Your age and your general health are also taken into account.
There are 30 different types of B and T-cell lymphomas, many of which affect the body in different ways, and respond differently to treatment. Some lymphomas grow quickly and need to be treated as soon as they are diagnosed. Others grow more slowly and do not need to be treated straightaway.
Both the grade of your lymphoma and whether it belongs to the B-cell or T-cell group can be determined by examining the cells from your lymph node biopsy under a microscope in the laboratory.