All about hairy cell leukaemia (HCL)

Hairy cell leukaemia (HCL) is a slow growing blood cancer that affects B cells, a type of white blood cell that helps fight infection. In HCL, these B cells grow out of control and do not work properly. They can build up in the bone marrow, spleen, and sometimes the liver, which can affect how these organs work.

Symptoms of HCL

Many people with HCL have no symptoms, and it is often found during a routine blood test. When you have symptoms, they are usually from a buildup of abnormal cells and less healthy blood cells.

Common symptoms of hairy cell leukaemia include:

fatigue
dizziness
pale skin
shortness of breath
frequent infections
bruising
bleeding
pain or fullness under the left ribs
swollen lymph nodes.

Causes of HCL

The exact cause of HCL is unknown. Changes to your genes affect how blood cells grow and develop. More than 95% of people with hairy cell leukaemia have a change to their BRAF gene, called BRAF V600E mutation.

Some factors that can increase your risk of developing HCL include:

gender as it is more common in men than women
age as most people diagnosed are over 50
ethnicity as it is more common in those of European descent
exposure to high-risk chemicals like pesticides, benzene, and solvents.

Stages of HCL

There is no standard staging system for HCL. Your doctor will use your test results to see how the leukaemia is affecting your body and decide on the best treatment.

Diagnosis of HCL

HCL is diagnosed with a number of tests.

Your haematologist will check:

how you’ve been feeling
your symptoms and how long you’ve had them
your health and your family’s health history.

You will have a physical exam to check for any swelling or pain. Tell your haematologist if you’ve noticed any changes in your body.

A baseline blood test is taken at diagnosis. This result is compared with future blood tests to check your response to treatment.

A blood test for HCL is looking for:

low red cells (anaemia)
low platelets (thrombocytopenia)
abnormal white cells (leukaemic cells).

These blood tests help identify the exact type and possible course of disease. They are often taken with your baseline blood test.

Immunophenotyping identifies the type of cells involved.
Cytogenetic testing looks for changes in chromosomes.
Immunoglobulin levels measure important proteins in the blood.
Polymerase chain reaction (PCR) testing checks for specific gene changes, like the BRAF V600E mutation which is present in 95% of people with HCL.

A bone marrow biopsy helps diagnose HCL. A needle is used to take a sample of bone marrow, usually from the back of the hip. A small amount of liquid bone marrow is removed and sent to the lab for testing. Often, a tiny piece of the bone itself is also taken to be examined.

Imaging scans may be done to check if HCL is affecting parts of your body, such as your spleen or lymph nodes.

These may include:

chest x-ray
computed tomography (CT) scan
magnetic resonance imaging (MRI) scan.

These tests are not always needed.

Fertility and HCL

Treatments for MPAL can affect fertility.

For women some treatments can cause damage to the ovaries.

For men it is possible to have low or abnormal sperm production.

For children and adolescents, the effect on future fertility depends on factors such as age, stage of puberty, and the type and intensity of treatment.

It is possible for your fertility to become normal again in the future, but it is difficult to predict.

It is important to ask your doctor about your risk of infertility as early as possible. There are some options for preserving fertility. Decisions about what options might be right for you usually need to be made before you start treatment.

You can read more about fertility on our webpage.

Treatments for hairy cell leukaemia

Your haematologist will consider many factors when discussing a treatment plan with you, including:

your overall health
your age
whether HCL is in other parts of your body
your wishes.

Active monitoring

Active monitoring (watch and wait) involves regular blood tests and health checks. No intervention is needed unless you have signs and symptoms which show the HCL is progressing.

Chemotherapy (chemo) is a common treatment for HCL. Chemo kills cancer cells and stops them from growing. It also damages healthy cells and causes side effects. There is information on chemotherapy side effects and how to manage them on our chemotherapy webpage.

The type of chemo recommended will depend on the treatment goal, your age, and medical history. Chemo can be given in combination with immunotherapy.

Your haematologist will provide you with information on your plan, including when and how often you will have it.

Treatment plans for HCL can be found on the Cancer Institute NSW website.

Immunotherapy is a type of biological therapy. It uses the immune system to recognise cancer cells and destroy them. Your treatment team will give this to you via a drip into a vein (intravenous).

Immunotherapy works by:

stimulating the immune system to find and attack cancer cells
removing barriers that are stopping the immune system killing cancer cells.

Rituximab is a monoclonal antibody used to treat HCL. It damages cancer cells and causes them to die by attaching to a protein called CD20 on the blood cancer cell. It is given as an intravenous infusion, usually in an outpatient unit.

Targeted therapy is a cancer treatment that finds and blocks parts of cancer cells that help them grow and spread.

BRAF inhibitors are an oral targeted therapy used to treat HCL when it relapses or is refractory. These medicines are not listed on the Pharmaceutical Benefits Scheme (PBS) for HCL, so you may have some out-of-pocket costs. Even so, your doctor may recommend them because research has shown they can be effective.

Two of these medicines are vemurafenib and dabrafenib. They work by blocking the BRAF V600E gene which is found in about 95% of people with HCL. This causes the cancer cells to die.

A splenectomy is the surgical removal of the spleen. It often becomes enlarged in HCL causing pressure and pain in the abdomen. It also destroys blood cells too quickly, which can cause low blood cell counts found in HCL. A splenectomy is sometimes recommended to:

relieve pressure and pain
manage persistent low blood cell counts.

A splenectomy doesn’t treat HCL but relieves symptoms.

Clinical trials may be available for HCL. They often compare new or combination therapies with current treatments, including side effects.

Many are randomised, meaning some patients receive the new treatment, and others receive standard care. Trials help improve future treatments and may offer access to costly new therapies not on the Pharmaceutical Benefits Scheme (PBS) in Australia.

If you are considering a clinical trial, your doctor will explain:

the possible risks and benefits
how it compares to standard treatment
what is involved.

You will need to give informed consent before taking part. Read more on our clinical trials webpage.

Survival rate for HCL

The survival rate of HCL is approximately 90% five years from diagnosis. Survival rate is a population based measure. Whereas your individual prognosis takes into account factors that can impact survival rate.

Your prognosis is estimated by your haematologist. It is a prediction of the likely course and outcome of your disease. The factors considered when discussing your prognosis include:

your subtype and stage
your overall health
your age.

Your prognosis might change if your HCL comes back or does not respond to treatment. There is no cure for hairy cell leukaemia (HCL), but treatment can lead to long periods of remission.

Follow-up care

Follow up care for HCL includes regular checkups with your treatment team. This is to check for long term side effects. You will also have tests and scans to make sure the HCL hasn’t come back (relapsed/recurred). You will likely need more treatment if the HCL returns.

Living with HCL

How HCL affects your everyday life will depend on many factors. It could be that you are returning or managing work, trying to exercise or managing your nutrition. There are some helpful resources and information to guide you on our living well with blood cancer webpage.

Caring for someone with HCL

We have a range of information and resources that may help when you are caring for someone with hairy cell leukaemia.

Information for carers and friends

Resources for carers

Resources for hairy cell leukaemia

Booklets to download:

Although no specific booklet is available for hairy cell leukaemia, the following booklet may have relevant information.

Non-Hodgkin lymphoma (NHL) information booklet

Read More

The CLL booklet has been translated into the following languages:

Optimal Care Pathway for lymphoma

An Optimal Care Pathway for lymphoma has been developed in association with the Cancer Council, Australia and you can access it below.

Your Guide to Best Cancer Care – lymphoma patients

A guide to help you, your family, and friends as you navigate through the healthcare system

Hairy cell leukaemia