Treatment for hairy cell leukaemia

In some cases, doctors use a process called “staging” to determine how developed the cancer is, and what treatments to use. However, in hairy cell leukaemia, there is no widely agreed upon staging system. Your treatment will be based on your symptoms, general health and blood counts.

It might take some time to understand your condition, and getting diagnosed can feel overwhelming.

Take your time to process the information, and when you are ready, your team will be there to support you with any questions you might have.

If you are not showing any symptoms, your team may decide to take an approach, where you will be actively monitored but without any treatment.

There is no evidence to suggest that having treatment earlier will improve the outcome in this case, and it’s thought to be best to save treatment until you need it.

You will have regular tests to check whether the leukaemia is progressing. About 10% of people (1 in 10) don’t have treatment straight away but are likely to have treatment at some point in the future.

For those who don’t have treatment straight away, it can be challenging coming to terms with the uncertainty, and knowing you are likely to experience treatment in the future.

You might find it helpful to connect with others in a similar position through our online community forum.

For most people who have been diagnosed with hairy cell leukaemia, chemotherapy is the main treatment option. Chemotherapy has a very high success rate at controlling hairy cell leukaemia.

Chemotherapy uses cytotoxic (anti-cancer) drugs to destroy cancer cells. In hairy cell leukaemia, the main drugs used are cladribine and pentostatin.

Both cladribine and pentostatin are types of purine nucleoside analogues. You normally have one or the other, but they both work in a similar way.

Chemotherapy is the main treatment for most people with hairy cell leukaemia. You might also have some other drugs as well, which increase the effectiveness of treatment, including targeted or immunotherapy drugs.

Targeted drugs work by targeting the differences that cancer cells have compared with healthy cells – this means they are good at seeking out cancer cells without targeting your healthy cells. Immunotherapy drugs work by harnessing your own immune system to find and attack the cancer cells.

You might be given a targeted immunotherapy drug called rituximab, alongside your chemotherapy. Rituximab works by recognising and sticking to the CD20 protein which is on the surface of the cancer cells. The immune system can then easily identify, target, and destroy the cancer cells.

Rituximab is usually given by intravenous (IV) infusion, which means through a drip into a vein. It’s often given just before the chemotherapy. When rituximab is combined with chemotherapy, it’s very effective at treating hairy cell leukaemia.

Rituximab is less effective when used by itself, but if you are unable to have any chemotherapy, it can be used in this way.

Chemotherapy is normally very effective at treating hairy cell leukaemia that has built up in the spleen.

However, sometimes the spleen can remain enlarged, which might cause pain or other problems. In these cases, some people might have surgery to remove their spleen. This is called a splenectomy.

Interferon alpha is a substance that the body produces naturally to help fight viruses. In hairy cell leukaemia treatment, it can be made and given as an injection, helping to attack cancer cells and slow down the production of abnormal B lymphocytes.

Interferon alpha is not used very often in hairy cell leukaemia, as more effective chemotherapy drugs have been developed. However, it may be used in some cases, for example, if someone cannot have chemotherapy.

Throughout your treatment plan, you might have other treatments to help reduce symptoms or prevent infections. For example, if you get an infection during treatment, you might have antibiotics, or a growth factor injection (G-CSF) which boosts your immunity.

Some people need blood transfusions during their treatment if they have low blood counts. A blood transfusion can give you a boost of red blood cells for example, if you have anaemia.

We have more information about blood transfusions.

After your treatment, you’ll have regular blood tests every few weeks to see how well your body has responded. Most people will also have another bone marrow biopsy 4 to 6 months after cladribine, or when they have finished pentostatin.

Most people with hairy cell leukaemia have a “complete response” to treatment. This means there are no detectable signs of leukaemia cells in your blood, bone marrow, spleen, or liver. Your blood counts will have returned to normal.

A “partial response” means that your blood counts are at normal levels, and the number of leukaemia cells in your bone marrow has reduced by at least 50% (by half). Your spleen and liver will have also shrunk by at least half.

If you have a partial response to treatment, you will probably need another round of chemotherapy combined with rituximab.

Sometimes, people may not respond well to their first treatment, meaning more than 50% (more than half) of the leukaemia cells still remain. This is called refractory hairy cell leukaemia – treatment for refractory hairy cell leukaemia is explained below.

If you have a complete response to your treatment, you are in remission.

In hairy cell leukaemia, remission means that you have no detectable signs of leukaemia in the body. Lots of people remain in remission for many years and can live a relatively normal life. However, most people are likely to need some treatment again at some point in the future.

After your treatment you will have regular follow-up appointments every 3-12 months, depending on how long you have been in remission for. Follow-up appointments are an opportunity for doctors to check:

• how well you are recovering from treatment and coping with having a chronic condition, both mentally and physically
• whether you might have developed any long-term side effects from treatment
• if you are showing any symptoms of the hairy cell leukaemia coming back.

A follow-up appointment will involve a blood test and the doctor will also ask about your general health and how you are feeling.

You do not have to wait until a follow-up appointment to raise any questions with a doctor though – if you have any concerns in between appointments, it’s important to get in touch with your hospital team.

People often stay in remission for years. However, if hairy cell leukaemia comes back - which is known as relapse - it will need more treatment. This is called second-line treatment, and your treatment plan will depend on how long you have been in remission.

If you relapse after being in remission for over two years, you are likely to have the same chemotherapy treatment you had the first time, with the addition of the targeted immunotherapy drug rituximab.

If you relapse after being in remission for less than two years, or have a poor response to your first treatment, there are different treatment options. Your team will talk to you about what’s best for you based on your general health and fitness, what treatment you’ve had in the past, and your own wishes.

You might have the same type of chemotherapy you originally had again, or you might have a different type of chemotherapy. You will either have chemotherapy on its own, or chemotherapy combined with rituximab. Your hospital team might also talk to you about clinical trials – these give you the opportunity to have a newer treatment that may or may not be better than existing treatments.

Treatment is often still very successful in people who relapse.