Treatment of hairy cell leukemia
Hairy cell leukemia (HCL) is a rare, slow-growing B-cell leukemia. It is named after the fine "hairs" seen on the cells under a microscope. Treatment is usually very effective.
01Short answer
02Simple explanation
The "hairy" cell. The leukemia cell has fine projections on its surface.
The spleen. Often enlarged; it can cause heaviness on the left.
Short treatment. Cladribine is often given as a course of a few days.
Long remission. Many people live for years without treatment.
03Scientific explanation
Purine analogues: cladribine and pentostatin disrupt DNA synthesis in lymphocytes; according to the NCI and consensus guidelines, complete remission rates are high. Adding rituximab can reduce measurable residual disease.
BRAF V600E: present in almost all classic HCL, it helps distinguish it from a similar disease, HCL-variant. Vemurafenib or dabrafenib (with trametinib) are used at relapse.
Other options: moxetumomab pasudotox was used in some countries; the BTK inhibitor ibrutinib in selected cases. Removing the spleen is now rare.
04What happens in the body?
When is treatment needed?
The main reasons are low blood counts, discomfort from an enlarged spleen and infections. Without these, the doctor may suggest monitoring.
How does treatment go?
Cladribine is usually given over 5–7 days by drip or under the skin. In the following weeks, blood counts may first fall and then slowly recover. During this time, infection prevention and vigilance matter.
If it comes back
HCL can return years later. Fortunately, the earlier treatment often works again, and targeted drugs (BRAF inhibitors) are an option.
05The HCL treatment path
A simplified outline.
06Treatment options in HCL
| Option | When? | Note |
|---|---|---|
| Monitoring | No symptoms | Regular blood tests |
| Cladribine ± rituximab | First line | Short course |
| Pentostatin ± rituximab | First line or relapse | Over several months |
| BRAF inhibitor ± rituximab | Relapse, unsuitable for purine analogues | By mouth |
| Ibrutinib | Selected relapses | By mouth |
| Splenectomy | Very rarely | Special cases |
* Simplified table; your doctor sets your plan.
07Key terms
- HCL
- Hairy cell leukemia.
- Purine analogue
- A drug group that disrupts DNA synthesis.
- Cladribine
- The main purine analogue in HCL.
- BRAF V600E
- The genetic hallmark of classic HCL.
- Splenomegaly
- An enlarged spleen.
- HCL-variant
- A disease similar to, but distinct from, HCL.
08Key points
- HCL is rare and slow-growing.
- Not everyone needs treatment straight away.
- Cladribine is short and effective.
- Remission is often long.
- Watch for infections after treatment.
- Targeted options exist at relapse.
09Frequently asked questions
How rare is HCL?
About 2% of all leukemias, more often in middle-aged men.
Does cladribine cause hair loss?
Usually not, or only a little.
How long does remission last?
Often many years; for some, more than ten.
Can I go back to work?
Many do once their blood counts recover.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
How rare is HCL?
Does cladribine cause hair loss?
How long does remission last?
Can I go back to work?
12Sources
- National Cancer Institute (NCI). Hairy Cell Leukemia Treatment (PDQ) – Patient Version
- Cancer Research UK. Treatment for hairy cell leukaemia
- MedlinePlus. Hairy cell leukemia
- Cancer Research UK. Hairy cell leukaemia
- Leukemia & Lymphoma Society. Hairy cell leukemia
- Blood (American Society of Hematology). Consensus guidelines for the diagnosis and management of patients with classic hairy cell leukemia (Grever et al., 2017)
- American Cancer Society. Types of Stem Cell or Bone Marrow Transplant
- American Cancer Society. Donating Stem Cells or Bone Marrow
- American Cancer Society. Stem Cell Transplant for Acute Lymphocytic Leukemia
- NHS (UK). Stem cell or bone marrow transplants