Lymphoma

What are lymphomas?

Lymphoma is cancer of the lymphatic system, a network of vessels that forms part of the body's immune system and carries lymph, a colourless, watery fluid that contains infection-fighting white blood cells called lymphocytes.

Dotted along the lymph vessels are groups of small, bean-shaped lumps called lymph nodes or glands. Clusters of lymph nodes are found under the arms, around the neck, under the chin and throughout the pelvis, groin, abdomen and chest. They make and store infection-fighting cells, especially lymphocytes.

Lymphoma results when a lymphocyte undergoes a malignant change and multiplies, eventually crowding out healthy cells and creating tumours. These tumours enlarge the lymph nodes and/or grow in other sites that are part of the immune system.

There are two principal kinds of lymphoma - Hodgkin and non-Hodgkin lymphoma. Non-Hodgkin is more common in older people, while Hodgkin lymphoma is more common in young adults between 15 and 30, and adults over the age of 50.

Lymphoma symptoms

Some of the symptoms of lymphoma are similar to those of leukaemia, although there may be no symptoms until the lymphoma has spread. It can start in almost any part of the lymphatic system and spread to almost any other part of the body, including the liver, bone marrow (the spongy tissue inside the large bones of the body that makes blood cells) and the spleen (an organ in the upper abdomen that makes lymphocytes and filters old blood cells from the blood).

Hodgkin lymphoma usually presents with painless swelling of the lymph nodes (lymphadenopathy), most frequently in the neck. Often people get a similar swelling if they have a simple cold. However, in Hodgkin lymphoma the swelling is much larger and firmer.

Other symptoms include:

• Fever for which no cause can be found
• Fatigue or extreme tiredness
• Paleness
• Night sweats (usually a sign of Hodgkin lymphoma)
• Weight loss

Often lymphomas have spread all over the body before the person is aware they have a problem.

Lymphoma causes

The causes of lymphoma have not yet been established.

Exposure to certain viruses and bacteria is associated with lymphoma. For example, Epstein-Barr virus may increase the risk of getting lymphoma and people who are HIV positive have an increased risk of lymphoma.

Genetic and environmental factors, such as exposure to pesticides, have also been implicated.

Lymphoma treatments

The two main types of lymphoma involve different types of white blood cell and it's important to get the exact diagnosis, determined mainly by what the cells look like under the microscope.

Each type of lymphoma needs slightly different treatments and has different prognoses or cure rates. Doctors will also work out how far it has spread around the body.

As recently as 1950, lymphoma was almost inevitably fatal, but these days more than 90 per cent of those newly diagnosed with Hodgkin lymphoma can expect to be cured. Non-Hodgkin lymphoma is less easily treated, with an overall cure rate of about 75 per cent.

The first thing a doctor will do to investigate suspicions of lymphoma is carry out a physical examination, feeling the lymph nodes in the neck, under the arms and in the groin, or felt. It can be slightly uncomfortable, but not painful. A doctor can also feel the abdomen for unusual swellings in the liver, which can happen if lymphoma spreads to that organ. Blood tests will also give a strong clue as to both the presence of disease - and what type it is.

The numbers of various types of cell are counted to make sure there are the right number, using automated laboratory machinery, and a small sample also examined directly under the microscope by a consultant haematologist, or blood specialist. Another key test is the x-ray or CT scan, which can look for swellings in the lymph nodes, liver, lungs and spleen.

For lymphoma, a biopsy of lymph nodes, normally from the neck and underarm area is taken to check for disease. All this information will help doctors work out how aggressive the cancer is, and how far it has already spread.

Lymphomas are usually treated by a combination of:

• Chemotherapy, where drugs are used to kill cancer cells and shrink tumours. The aim is to get the cancer into ‘remission', which means no evidence of cancer can be found on scans or blood tests
• Radiotherapy, where high-energy x-rays are used to kill the cancer cells
• Surgery

Bone marrow transplants are also sometimes also needed, particularly if the first chemotherapy treatment fails and more powerful drugs have to be used. The bone marrow is found at the centre of the body's larger bones, such as in the spine and upper leg, producing blood cells and helping the body fight infection. If high-dose chemotherapy is to be used, this may permanently damage the bone marrow, so it has to be replaced afterwards.

Many children with lymphoma will be offered the chance to be treated as part of a clinical trial. While they or their family may be frightened by the idea that they're being used as some sort of guinea pig, they'll be very carefully monitored by doctors during the trial. Trials are the only way to find better treatments.

Drugs can be given to stimulate the production of cells vital to rebuilding the bone marrow, which are then harvested and replaced after the treatment. Or a donor may have to be found whose bone marrow is an exact match for the patient. A close relative may be able to provide a match, but this is far from certain. The Anthony Nolan Bone Marrow Trust keeps a register of 130,000 volunteers who are all prepared to give bone marrow if they prove a match for a patient.

Advice and support

Lymphoma Association

• Helpline: 0808 808 5555
• Website: www.lymphoma.org.uk