What is Non-Hodgkin’s Lymphoma

Non-Hodgkin’s Lymphoma usually arises from the lymphocytes found within the lymph nodes or lymphoid tissue within other organs.
Lymph nodes are groups of lymphatic cells held together by connective tissue, and are distributed throughout the body. Lymph fluid is produced when the blood passes through the tissues. Most of the cellular content of the blood (white cells, red cells and platelets) stays within the blood vessels, some of the liquid content (water, proteins, antibodies, fats) and some white cells pass through and bathe the tissues in nutrients.
The lymphatic fluid is collected by the lymphatic vessels and channeled to the local lymph nodes, where it is filtered and passed onwards to the next set of lymphatic vessels. The direction of drainage is from the periphery to central, with the lymph ultimately emptying into the subclavian vein via the thoracic duct in the chest. The lymph nodes produce lymphocytes which produce antibodies.
There are 2 types of lymphocytes. B-cells are produced by lymph nodes and are responsible for producing antibodies. T-cells attack and kill foreign cells (sometimes cancer cells, sometimes transplanted organs) and are partly responsible for sensitizing B-cells to produce antibodies against foreign substances. When these cells malfunction, they can produce antibodies to normal tissues, causing auto-immune disease.
Most (90%) cases of Non-Hodgkin’s lymphoma derive from B-cells.
The many different types of Non-Hodgkin’s lymphoma. They are usually graded as low grade, intermediate grade and high grade.
The low grade lymphomas are usually slow growing and therefore compatible with a long life expectancy. They are not usually curable, but respond to treatment with long remission periods usually achievable.
High grade lymphomas usually respond rapidly to treatment and a good proportion are curable. Please see our section on ‘What is Cancer?’ in the haematology or oncology suites for further explanation.

Statistics on Non-Hodgkin’s Lymphoma

It is relatively uncommon, occurring in approx 3 per 100 000 and occurs in different age groups. It is generally a disease of adults (the risk increasing with age). It occurs with sex incidence being slightly more common in men.
Geographically, the tumour is found worldwide, with variation depending on the underlying cause. For instance Burkitt’s lymphoma is more common in Africa.

Risk Factors for Non-Hodgkin’s Lymphoma

The cause of most cases of Non-Hodgkin’s lymphoma is unknown although a number of predisposing factors have been identified. These are:
Some types of NHL (Non-Hodgkin’s lymphoma) (e.g. Burkitt’s lymphoma) have been shown to contain particles of the Epstein-Barr Virus.
HIV/AIDS predisposes to NHL, possibly as a result of the immune suppression but the virus itself may be implicated.
Immune suppression from anti-rejection drugs.
Exposure to certain chemicals.
Previous anti-cancer treatment.
Certain genetic and chromosomal abnormalities.

Progression of Non-Hodgkin’s Lymphoma

This type of tumour spreads by passage through the lymphatic channels to adjacent lymph nodes. As the spleen is an important organ of the lymphatic system, it may also be involved. Later in the disease, it may spread via the bloodstream to the liver, other organs and bone.

How is Non-Hodgkin’s Lymphoma Diagnosed?

General investigations may show anaemia or abnormal liver function. If haemolysis is present the serum haptoglobin level may be lowered.

Prognosis of Non-Hodgkin’s Lymphoma

Please read the information above about high grade and low grade lymphomas. The prognosis can vary widely depending on the lymphoma type. For example:
 

  • Follicular small cleaved cell lymphoma has an average survival of 9 years.
  • Low grade lymphomas usually have a first remission lasting approximately 3 years.

    How is Non-Hodgkin’s Lymphoma Treated?

    If the disease is very localised, e.g. Stage 1 disease, involving only the neck lymph nodes, the usual treatment is localised radiotherapy which is very effective. This mode of treatment may also be used to treat groin lymph nodes (using the “inverted Y field”). Otherwise, radiotherapy is reserved for treating specific problems that require focal therapy, such as bone pain from bone involvement or treating an obstruction of the Superior Vena Cava (the large vein that drains the face and upper body).
    Stage 2, 3 and 4 disease (and some types of Stage 1 disease) are treated with chemotherapy. There are a variety of treatments which are effective for NHL. Some involve both chemotherapy and radiotherapy.
    As a general rule, low-grade non-Hodgkin’s lymphoma is usually treated with chlorambucil and prednisolone. This has the effect of putting people into a remission for a variable period of time. The low-grade non-Hodgkin’s lymphomas usually relapse, but also usually respond to re-treatment.
    High-grade lymphomas are potentially curable with intensive chemotherapy. Some examples are given below:
    Treatment for non-Hodgkin’s lymphoma had not really changed much in 25 years until very recently. Rituximab, a specific monoclonal antibody against a protein found on B lymphocytes, has brought the first major advance in treatment since CHOP was first used in the 1970s.
    Currently only available on the PBS in Australia for low-grade non-Hodgkin’s lymphoma, haematology and oncology specialists are eagerly awaiting the results of trials involving rituximab plus chemotherapy for high-grade lymphoma. It is expected that rituximab will increase the effectiveness of chemotherapy for this disease.
    As every patient is different, your treating specialist will be able to advise you on which treatment is best for you.
    The symptoms that may require attention are fatigue from anaemia, and on occasion pain from organ or bone involvement.
    Improvement in symptoms is an important measurement. Specific monitoring may be by measurement of the size of the involved lymph nodes. This may often be done with a simple ruler of tape measure if the nodes are easily felt e.g. in tne neck. If the lymph nodes are deep inside, e.g. in the chest or abdomen, then imaging such as CT can show the response to treatment.

    Non-Hodgkin’s Lymphoma References

    1. Mayo Clinic
    2. MEDLINE Plus
    3. The Sidney Kimmel Comprehensive Cancer Center John Hopkins University

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