What is non-Hodgkin lymphoma?
Non-Hodgkin lymphoma (NHL) is the name given to a group of cancers that develop from B-lymphocytes (B-cells), T-lymphocytes (T-cells) and natural killer cells (NK cells).
Lymphoma starts in the body’s lymphatic system, which is part of the immune system. The lymphatic system also helps fluid move through the body. Lymphoma can start anywhere in the body where lymph tissue is found. The major sites of lymph tissue are lymph nodes, spleen, bone marrow, thymus, adenoids, tonsils and digestive tract. Over time, malignant lymphocytes (called lymphoma cells) crowd out normal lymphocytes and eventually the immune system becomes weakened and can no longer function properly.
Non-Hodgkin lymphoma is the most common type of lymphoma in New Zealand, with approximately 1000 people diagnosed every year. NHL is seen in all age groups, but is more common in people over the age of 50.
Types of non-Hodgkin lymphoma
Knowing the exact type of lymphoma you have is important because it helps predict the course of your disease, and how it should be treated.
There are many different subtypes of non-Hodgkin lymphoma which are generally divided into the following two main groups:
- B-cell lymphomas (those that arise from developing B-lymphocytes)
- T-cell lymphomas (those that arise from developing T-lymphocytes)
The majority of non-Hodgkin lymphomas (over 80%) are B-cell lymphomas.
Types of NHL can also be grouped based on how fast they grow and spread. These are known as:
- Indolent lymphomas: They grow and spread slowly. Some indolent lymphomas might not need to be treated immediately but can be monitored closely instead.
- Aggressive lymphomas: They grow and spread quickly. They usually need to be treated right away.
Signs and symptoms
The symptoms of NHL vary from person to person. Some people do not have any symptoms when they are first diagnosed. Their NHL is discovered incidentally when they have a blood test or check-up for a different reason. Some people will have symptoms, which are explained below.
In NHL, the normal blood cells in the bone marrow, blood and lymph glands can be crowded out by large numbers of lymphoma cells. This can result in symptoms such as anaemia, bleeding, bruising and infections.
Anaemia (low haemoglobin)
- Lack of energy (lethargy)
- Feeling tired all the time (fatigue)
- Shortness of breath, especially when exercising
- Dizziness
- Pale skin.
Bleeding and bruising (low number of platelets)
- Bruising easily
- Minor cuts or injuries that take a long time to stop bleeding
- Frequent or severe nosebleeds or bleeding gums
- Red or purple pinhead-sized spots on the skin called petechiae
- Heavier or more frequent menstrual periods.
Infections
- Fever (high temperature)
- Shivering
- Coughing up yellow or green phlegm
- Fatigue or extreme tiredness.
Swollen lymph glands (lumps)
People with NHL can have firm, usually painless, swelling of a lymph node. The most common sites are the neck, under the arms or in the groin. Sometimes NHL starts in the lymph nodes in deeper parts of the body like the stomach (causing bloating or fullness after eating) or the chest (causing coughing, pain or difficulty breathing).
B symptoms
Drenching night sweats, unexplained weight loss and fevers are sometimes called B symptoms.
Other symptoms
- Generalised itching
- Rash
- Loss of appetite
- Blood clots.
Causes
Like other cancers, NHL is thought to develop after DNA is damaged, causing genetic mutations (errors). NHL is not contagious. In most cases, people who are diagnosed with NHL have no family history of it.
Certain factors put some people at a higher risk of developing NHL. These include:
- Immunosuppression – A small percentage of lymphomas occur in people whose immune system has been weakened (immunosuppressed) either by a viral infection such as human immunodeficiency virus (HIV) or because of drugs which affect the function of the immune system (immunosuppressants).
- Infection – In some cases, particularly in people who are immunosuppressed, viral infections such as Epstein-Barr virus (EBV) or human T-lymphotropic virus (HTLV-1) or bacteria such as H. pylori, may damage developing lymphocytes and increase the risk of lymphoma.
- Chemicals – There is some evidence that people exposed to high concentrations of agricultural chemicals such as pesticides and fertilisers may have a higher risk of developing lymphoma.
- Radiation – People who have been treated for cancer using ionising radiation (X-rays and some other radioactive materials) or who have been exposed to significant or long-term radiation may also be at an increased risk of developing lymphoma.
Diagnosis
Your doctor will diagnose NHL by talking with you about how you are feeling, looking at your blood and taking a biopsy (sample of a lump or lymph node).
NHL affects everyone differently. You may need a few different tests before lymphoma is diagnosed, and to identify what subtype and stage your lymphoma is.
Blood samples are taken from a vein in your arm and sent to the laboratory to be examined. They will likely check your full blood count (FBC), blood chemistry and may do specialised tests to identify any abnormalities with the chromosomes, genes or DNA.
A lymph node biopsy is a procedure where all or part of a lymph node is removed and sent to be examined in the laboratory.
Information from a lymph node biopsy can confirm what type of lymphoma you have and is used to decide the best type of treatment.
You may need additional tests, which may include:
- More blood tests
- A lumbar puncture: where fluid is taken from the spine to test whether the lymphoma involves the brain or spine.
- A bone marrow biopsy: where a sample is taken from the hipbone to determine if there are cancer cells in the bone marrow.
- A CT scan: a radiology procedure that uses a combination of X-rays and computer technology to produce detailed images of any part of the body. A special liquid may be given before the test to help outline the abdomen and occasionally injections are given into a vein to outline different organs. People usually lie on their back for about ten minutes during the scan.
- A MRI Scan: uses magnet and radio waves to produce a detailed 3D image of part of your body.
- A PET scan: a specialised CT scan that uses a radioactive tracer and special cameras to detect areas in the body affected by lymphoma.
Treatment
Some types of NHL grow very slowly and do not need treating for a long time, if at all. Treatment for each person is determined by factors such as age, general health, type of lymphoma and where it has spread within your body.
The aim of treatment is to destroy the lymphoma cells and stop any progression and improve quality of life by treating the symptoms and complications associated with lymphoma.
Types of treatment for NHL include:
- Active monitoring (watch and wait): People with indolent lymphomas who don’t have any symptoms may not need to start any treatment but will be monitored by their doctor with regular check-ups and blood tests.
- Chemotherapy: The main form of treatment for NHL is chemotherapy. The type, dose, and timing of chemotherapy will depend on the type of NHL you have and is often given as a combination of drugs what all work in a different way.
- Steroid therapy: Corticosteroids such as prednisone and dexamethasone, are commonly used in NHL treatment. They work alongside chemotherapy drugs to kill lymphoma cells.
- Immunotherapy and targeted treatments: Immunotherapy drugs help a person’s own immune system to recognise lymphoma cells and kill them. There are different types of immunotherapy drugs and targeted drugs that are used for treating lymphomas.
- Radiotherapy: Using high energy X-rays to kill cancer cells and shrink tumours or enlarged lymph nodes.
- Stem cell transplant: A stem cell transplant (also known as a bone marrow transplant) may be recommended for treatment of your lymphoma.
- CAR T-cell therapy: Stands for chimeric antigen receptor T-cell therapy and works by changing a person’s own T-cells so they can recognise and attack cancer cells. For more information about CAR T-cell therapy in New Zealand visit the Malaghan Institute of Medical Research website .
