Hairy cell leukaemia (HCL) is a rare type of chronic leukaemia (chronic or slow-growing cancer of the blood and blood forming tissues) that develops from lymphocytic white blood cells. More specifically, they develop from B lymphocytes, or B-cells, which are responsible for producing the immunoglobins (antibodies) that help our body fight infections.
The naming of HCL comes from their cellular appearance under the microscope, where tiny hair-like projections are seen coming off the surface of leukaemic cells.
HCL has a higher incidence in males and is most commonly diagnosed in people over 50 years of age. However, anyone can develop this disease.
Treatment
If a HCL is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodes) indicates whether the cancer has spread to nearby lymph nodes.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localised cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Grade I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including fertility, age, stage of disease and overall health.
Treatment options for patients with HCL may include:
- Chemotherapy.
- Targeted therapies.
- Surgery, usually a total splenectomy (removal of the spleen).
- Watch and wait.
- Clinical trials.
- Palliative care.
For more information on the treatment options, please refer to the Rare Cancers Australia Treatment Options page.
Risk factors
Because of how rare HCL is, there has been limited research done into the risk factors of this disease. However, a family history of HCL could potentially be a risk factor.
Early symptoms
People with HCL may experience some of the following symptoms:
- Anaemia, which carries its own set of symptoms:
- Tiredness.
- Dizziness.
- Paleness.
- Becoming unusually short of breath when physically active.
- Frequent and/or recurrent infections.
- Abdominal discomfort in the upper left side (spleen enlargement).
- Painless swelling of the lymph nodes.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis/diagnosing
If your doctor suspects you have HCL, they will order a range of diagnostic tests to confirm the diagnosis, and refer you to a specialist for treatment.
Physical examination
Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities.
Blood tests
Your doctor will recommend a blood test for check for signs of HCL. The most common test is a full blood count, which will analyse the levels of red blood cells, white blood cells and platelets in the blood. Low counts in any of these categories could be indicative of disease.
Imaging
The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), and/or positron emission tomography (PET scan), to check for signs of metastasis.
Bone marrow biopsy
Once the location of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. In most cases, this will be done by a bone marrow aspiration and biopsy. This process involves inserting the needle into the hipbone (or the breastbone in some cases) to remove samples of solid and liquid bone marrow. These samples will then be analysed for cancer cells.
Prognosis (Certain factors affect the prognosis and treatment options)
While it is not possible to predict the exact course of the disease, your doctor may be able to give you a general idea based on the rate and depth of tumour growth, susceptibility to treatment, age, overall fitness, and medical history. Generally, early-stage HCLs have a better prognosis and survival rates. However, if the cancer is advanced and has spread, the prognosis may not be as good and there may be a higher risk of cancer recurrence. It is very important to discuss your individual circumstances with your doctor to better understand your prognosis.
References
Some references are to overseas websites. There may be references to drugs and clinical trials that are not available here in Australia.