Who is affected by HCL and what causes it?

Freephone helpline 0808 808 5555 information@lymphomas.org.uk www.lymphomas.org.uk Hairy cell leukaemia Hairy cell leukaemia (HCL) is a rare and very distinctive cancer of blood cells called B lymphocytes (B cells). These B cells are specialised white blood cells that are involved in the body s immune system. HCL was given its unusual name because the malignant cells were observed to have tiny hair-like projections on their surface when they were examined under the microscope. Although its name includes the word leukaemia (because these malignant white blood cells are found in the bone marrow and circulating in the bloodstream) HCL is officially classified by the World Health Organisation as a low-grade (slow-growing) non-hodgkin lymphoma. It has some similarities to chronic lymphocytic leukaemia (CLL), which is a much more common non-hodgkin lymphoma. This article is aiming to answer the main questions that people with newly diagnosed HCL might ask: Who is affected by HCL and what causes it? How does HCL develop? What are the symptoms? How is HCL diagnosed? How is HCL treated? What happens next? Who is affected by HCL and what causes it? Fewer than 200 people are diagnosed with HCL each year in the UK. It usually occurs in people between the ages of 40 and 60 and it is about five times more common in men than it is in women. The cause of HCL is not known. It is not infectious and is not passed down through the family. How does HCL develop? Like all cancers, HCL begins as a single cell that goes wrong in a way that makes it divide and survive inappropriately past its normal lifespan one cell divides into two, two into four, four into eight, and so on. Eventually the body ends up with billions of these abnormal cells, though the cause of the changes that take place in the B cells to make them malignant is not known. In HCL the malignant B cells that have started to grow out of control mainly accumulate in the bone marrow (the spongy central part of some of our larger bones) and in the spleen, an organ which lies in the upper left-hand side of the abdomen. They are not usually found in lymph nodes (glands) or in the bloodstream in large numbers. 1/6

What are the symptoms of HCL? HCL is a lymphoma that develops slowly and some people will have no symptoms for quite a long time or will have non-specific symptoms that might have suggested other, more common illnesses. If the HCL cells accumulate in your bone marrow they can stop the marrow from working properly. Because the bone marrow is the factory that makes normal blood cells that circulate round the body in the bloodstream, you can develop shortages of healthy red blood cells, white blood cells and platelets. HCL cells can also accumulate in the spleen and about two-thirds of people with HCL will be found to have an enlarged spleen when they are examined by the doctor. As more and more HCL cells accumulate, they sometimes release chemicals which cause tiredness, weight loss and sweating. The accumulating HCL cells can therefore lead to symptoms such as: tiredness and breathlessness due to anaemia, a shortage of red blood cells frequent infections because the numbers of infection-fighting white blood cells is low unexplained bruising or bleeding due to low numbers of platelets, which are normally involved in blood clotting abdominal discomfort or swelling due to enlargement of the spleen unexplained weight loss or sweating. How is HCL diagnosed? Apart from the clues provided by your symptoms and any signs of an enlarged spleen, doctors diagnose HCL by examining the blood and the bone marrow. The blood sample usually shows the HCL cells and it might also show low numbers of healthy blood cells. A bone marrow sample is usually needed to find HCL cells and confirm the diagnosis. This sample is taken from your hip bone after the skin has been numbed with a local anaesthetic. A needle is used to take some bone marrow cells through a syringe (a bone marrow aspirate) and then a larger sample of marrow with a tiny piece of bone is taken (a trephine biopsy). This larger sample is taken because the hairy cells can be difficult to find in the aspirate sample alone. Other tests: You will have a full examination and other tests to assess your general health. You might have an ultrasound or computed tomography (a CT scan) to assess your spleen and your other abdominal organs. Occasionally people with HCL will be found have enlarged lymph nodes in the abdomen. If these are detected by the tests, some of the lymph node tissue is often removed and examined because this can be a sign that the disease has turned into a faster-growing (or high-grade ) kind of lymphoma, which would need a different form of treatment from the teatments used for classic HCL. 2/6

How is HCL treated? A few people do not need treatment straightaway and if your medical team decides that this would be the best approach you will be regularly monitored in the clinic with blood tests. You would not be treated until your symptoms become troublesome or your blood counts fall. You might hear this active monitoring approach called watch and wait. This can be a difficult period to go through because you might feel that nothing is being done, but research has shown it to be the best approach in some people. Most people with HCL, however, will need to be treated once the diagnosis has been made. The treatments for HCL are very effective and for most people the disease will not shorten their life expectancy. The treatments for HCL are aiming to reduce the numbers of malignant cells in the bone marrow and blood and restore the levels of healthy blood cells. The mainstay of treatment is chemotherapy. Chemotherapy The main treatment for HCL is chemotherapy, which means treatment with anti-cancer drugs, and it is very effective. The most commonly used drug is cladribine, which can be given into a vein or as an injection just beneath the skin. It is given every day for 5 7 days. Almost 95% of patients respond to this drug, many people achieving a complete remission (where the disease cannot be detected in the bone marrow using the standard tests) and this can last for many years. Another drug that might be used is pentostatin, which is given into a vein every other week for 3 4 months. Pentostatin and cladribine are equally effective. The main side effect of both drugs is a temporary lowering of blood counts, which increases the risk of infection and bruising or bleeding. Pentostatin can also sensitise the skin to sunlight so it is important to stay out of the sun while receiving this drug. Your medical team will advise you of any other special precautions you should take while you are on these drugs or afterwards. One precaution that you will be given information on is the need for you to receive irradiated blood if you need blood transfusions in future. This is blood that has been treated with radiation in order to prevent a rare complication of transfusion called graft-versus-host disease or GVHD (cladribine and pentostatin make people more prone to develop GVHD). There is an NHS patient information leaflet available about irradiated blood (http://hospital.blood.co.uk/library/pdf/english_irradiated_blood.pdf). You will usually have another bone marrow biopsy taken after your course of treatment is finished to check how well the HCL has responded. Splenectomy Splenectomy (an operation to remove the spleen) is rarely needed nowadays because chemotherapy is such an effective treatment for HCL, but a few people with a very enlarged spleen will have this operation to relieve abdominal discomfort or boost their blood counts. We have an information sheet on splenectomy. Please contact the helpline team if you would like a copy (0808 808 5555) or you can read it on our website (www.lymphomas.org.uk). 3/6

A few people do not require further treatment at all for their HCL after a splenectomy, but most people will go on to need chemotherapy. The chemotherapy is not usually started until at least 6 months have passed since the operation. Interferon Interferon is a biological or targeted therapy that boosts the body s own immune system to destroy malignant cells. It was given more commonly in the past for HCL but it has largely been replaced nowadays by cladribine and pentostatin. It is sometimes given before you have these chemotherapy drugs if your blood counts are very low, especially if you have been having repeated infections. It is given by injection just beneath the skin, three times a week and its main side effect is flu-like symptoms. Later treatments for HCL HCL is a chronic (long-lasting) disease that is prone to come back and need further treatment. This is called a relapse and if this happens a further course of treatment can be given and, once again, this is often very successful. Cladribine or pentostatin are often used to treat relapsed HCL if these drugs were effective the first time. Which one you will have will depend on how quickly the relapse has happened after the initial treatment and on which drug you had initially. Rituximab Rituximab is a monoclonal antibody, which is another form of biological therapy. Monoclonal antibodies are specially manufactured to recognise and target a protein on the surface of cancer cells. This stimulates the body s own immune system to destroy the malignant cells. Rituximab is sometimes given if the HCL responds poorly to the initial chemotherapy treatments (this is described as being refractory to treatment) or if HCL relapses. It can be given on its own but it is usually given together with cladribine or pentostatin. Follow-up Although people with HCL are usually very successfully treated and have long periods of being disease-free, it can come back years later, as we have described above. You will therefore be seen for periodic check-ups in the outpatients clinic, where you will have blood tests and an opportunity to discuss any worries about your health. If you have any new symptoms between these appointments you can be seen at the clinic early. Because HCL is a disease that people often live with for many years you might find our booklet, Living with lymphoma helpful. It covers the more day-to-day aspects of living with a chronic malignant condition like HCL, such as how to cope with tiredness and other symptoms, your feelings and relationships, diet and exercise and other practical things like managing medical appointments, your finances, travel and vaccinations. 4/6

More information The Lymphoma Association produces a wide range of booklets and information sheets on all aspects of lymphoma, including information about tests and investigations, chemotherapy and coping with the side effects of chemotherapy. We also have information on how to cope with the difficulties of living with an illness that can extend over many years. Visit our website at www.lymphomas.org.uk or phone our freephone helpline on 0808 808 5555 if you would like to receive any of this information or if you would like to talk to someone about your experiences or anxieties. Feedback We continually strive to improve our information resources for people affected by lymphoma and we would be interested in any feedback you might have on this article. Please visit www.lymphomas.org.uk/feedback or email publications@lymphomas.org.uk if you have any comments. Alternatively, please phone our freephone helpline on 0800 808 5555. Acknowledgement The Lymphoma Association is grateful to Professor Andrew Pettitt, consultant haematologist at the Royal Liverpool University Hospital and Chairman of the UK CLL Forum, for his help with the writing of this article. Useful organisations CLL Support Association c/o 39 40 Eagle Street London WC1R 4TH 0800 977 4396 via website www.cllsupport.org.uk CancerHelp UK (Cancer Research UK) 0808 800 4040 (Monday Friday, 9am 5pm) via website http://cancerhelp.cancerresearchuk.org/ Leukaemia & Lymphoma Research 39 40 Eagle Street London WC1R 4TH 020 7405 0101 (Monday Friday, 9am 5pm) info@beatingbloodcancers.org.uk www.leukaemialymphomaresearch.org.uk 5/6

References Clinical Task Force of the British Committee for Standards in Haematology (British Society for Haematology). Revised guidelines for the diagnosis and management of hairy cell leukaemia and hairy cell leukaemia variant. 2012. BCSH, London, UK. British Committee for Standards in Haematology (for NHS Blood and Transplant). Information for patients needing irradiated blood (leaflet). 2011. Available at: http://hospital.blood.co.uk/ library/pdf/english_irradiated_blood.pdf Swerdlow SH, et al. (eds) WHO Classification of tumours of haematopoietic and lymphoid tissues, 2008. International Agency for Research on Cancer. Lyon, France. Else M, et al. Long-term follow-up of 233 patients with hairy cell leukaemia, treated initially with pentostatin or cladribine, at a median of 16 years from diagnosis. British Journal of Haematology, 2009. 145: 733 740. Goodman GR, et al. Extended follow-up of patients with hairy cell leukemia after treatment with cladribine. Journal of Clinical Oncology, 2003. 21: 891 896. Goodman GR, et al. Hairy cell leukaemia: an update. Current Opinion in Hematology, 2003. 10: 258 266. We make every effort to ensure that the information we provide is accurate but it should not be relied upon to reflect the current state of medical research, which is constantly changing. If you are concerned about your health, you should consult your doctor. The Lymphoma Association cannot accept liability for any loss or damage resulting from any inaccuracy in this information or third party information such as information on websites which we link to. Please see our website (www.lymphomas.org.uk) for more information about how we produce our information. Lymphoma Association PO Box 386, Aylesbury, Bucks, HP20 2GA Registered charity no. 1068395 Produced 03.02.2012 Next revision due 03.02.2014 6/6