This information is about a specific type of non-Hodgkin lymphoma (NHL), known as small lymphocytic lymphoma. It should ideally be read with our general information about non-Hodgkin lymphoma.

Small lymphocytic lymphoma is a cancer of the B-lymphocytes. It is very similar to a form of leukaemia called chronic lymphocytic leukaemia (CLL), which is also a cancer of B-lymphocytes. In small lymphocytic lymphoma, the abnormal lymphocytes mainly affect the lymph nodes, whereas in chronic lymphocytic leukaemia the abnormal lymphocytes mainly affect the blood and the bone marrow. The spleen may be affected in both conditions.

Small lymphocytic lymphoma accounts for about one in 25 of all cases of non-Hodgkin lymphoma. It can occur at any time from young adulthood to old age, but is rare under the age of 50. It is twice as common in men as in women.

The causes of small lymphocytic lymphoma are unknown. Small lymphocytic lymphoma, like other cancers, is not infectious and cannot be passed on to other people.

The first sign of the condition is often a painless swelling in the neck, armpit, or groin, caused by enlarged lymph nodes. Sometimes more than one group of nodes is affected. The lymphoma may spread to involve various organs in the body, such as the spleen, the lung and the bone marrow. Some people experience a loss of appetite and tiredness.

Other symptoms may include sweating at night, unexplained high temperatures, and weight loss. These are known as B symptoms.

A diagnosis is made by removing an enlarged lymph node, or part of it, and examining the cells under a microscope (biopsy). You will be referred to a surgeon for this procedure. It is a very small operation and may be done under local or general anaesthetic. Biopsies may also be taken from other body tissues.

Additional tests, including blood tests, x-rays, scans, and bone marrow samples, are then used to get more information about the type of lymphoma and how far it has spread in the body. This information is used to help decide which treatment is most appropriate for you.

Staging

The stage of NHL describes how many groups of lymph nodes are affected, where they are in the body, and whether other organs such as the bone marrow or liver are involved.

• Stage 1 The lymphoma is only in one group of lymph nodes, in one particular area of the body.
• Stage 2 More than one group of lymph nodes is affected, but all the affected nodes are contained within either the upper half or lower half of the body. The upper half of the body is above the sheet of muscle underneath the lungs (the diaphragm), and the lower half is below the diaphragm.
• Stage 3 Lymphoma is present in lymph nodes in both the upper and the lower parts of the body (ie in lymph nodes both above and below the diaphragm). Your spleen is considered as a lymph node in this staging system.
• Stage 4 The lymphoma has spread beyond lymph nodes to other lymphatic organs – for example, to sites such as the bone marrow, liver or lungs.

The stage usually includes the letter A or B, which describes whether the B symptoms are present or not (eg stage 2B). Sometimes the lymphoma can start in areas outside the lymph nodes, and this is represented by the letter E, which stands for extranodal (eg stage 3AE).

Grading

For practical reasons, non-Hodgkin lymphomas are also divided into two groups: low- and high-grade. Low-grade lymphomas are usually slow-growing, and high-grade lymphomas tend to grow more quickly.

Small lymphocytic lymphoma is a low-grade lymphoma and usually develops very slowly. However, sometimes it can change (transform) into a higher-grade lymphoma and become faster-growing.

Active surveillance (active monitoring)

If the lymphoma is causing no symptoms, it may not be necessary to give treatment immediately. You will be seen regularly by your cancer specialist/doctor and treatment will be given when you start to get symptoms. It may be some time before this happens.

Chemotherapy

If treatment is necessary, this type of lymphoma is usually treated with chemotherapy. Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. Small lymphocytic lymphoma is very sensitive to chemotherapy and often disappears with simple drug treatment. When there is no sign of the lymphoma, this is known as a remission. The chemotherapy is often given in tablet form, using a drug called chlorambucil, or with a drug called fludarabine, which is given by injection into a vein or as a tablet.

Although small lymphocytic lymphoma usually responds well to chemotherapy, it is likely to come back in the future. However, further chemotherapy can be given and the lymphoma may disappear again. This pattern may repeat itself. This means that many people can have their lymphoma controlled, and lead a relatively normal life, often for many years.

High-dose treatment with stem cell support

High-dose chemotherapy with a bone-marrow or stem-cell transplant has been used to treat a small number of people with small lymphocytic lymphoma. This type of treatment involves having very intensive chemotherapy and sometimes radiotherapy.

As side effects can be severe, some types of high-dose treatment are not given to people over the age of 45–50, while others can be given to people of up to 65 years who are fit enough. The intensity of the treatment increases the risks of serious side effects for people over this age.

Radiotherapy

Radiotherapy is the use of high-energy rays to destroy cancer cells, while doing as little harm as possible to the healthy cells. It may be used when the lymphoma cells are contained in one or two areas of lymph nodes in the same part of the body (Stage 1 or 2). It may also be given in addition to chemotherapy.

Steroid therapy

Steroids are drugs which are often given with chemotherapy to help treat lymphomas. They also help you feel better and can reduce feelings of sickness.

Monoclonal antibody therapy

Other treatments that have been used to treat small lymphocytic lymphoma are the monoclonal antibodies alemtuzumab, which is also known as MabCampath®, and sometimes, rituximab, known as Mabthera®. Monoclonal antibodies are drugs that recognise, target, and stick to particular proteins on the surface of cancer cells, and can stimulate the body’s immune system to destroy the cell.

More monoclonal antibody treatments are being researched. Some are attached to a small dose of radioactivity to see whether this will make them more effective. The most commonly used radioactive monoclonal antibody treatments for this type of lymphoma are 90Y ibritumomab tiuxetan (Zevalin®), and 131 tositumomab (Bexxar®).

New treatments for small lymphocytic lymphoma are being researched all the time, and you might be invited by your doctor to take part in a clinical trial to compare a new treatment against the best available standard treatment. Your doctor must discuss the treatment with you, and have your informed consent before entering you into any clinical trial.

The need for practical and emotional support will of course be individual. For some people with small lymphocytic lymphoma, life may seem largely unaffected; for others the diagnosis of cancer may be a cause of great fear and distress. If you would like to discuss the condition, its treatment, or the practical and emotional problems of living with small lymphocytic lymphoma, please contact our cancer support service.

This section has been compiled using information from a number of reliable sources, including:

• Oxford Textbook of Oncology (2nd edition). Eds Souhami et al, Oxford University Press, 2002.
• Wintrobe’s Clinical Haematology (11th edition). Eds Lee et al, Williams and Wilkins, 2004.
• Improving Outcomes in Haemato-Oncology. National Institute of Clinical Excellence, November 2003.

For further references, please see the general bibliography.