Leukaemia is a group of cancers that affect blood-forming cells. Treatment depends on which cells are affected, whether the leukaemia is acute or chronic, and what genetic changes are found. Acute leukaemias generally need urgent specialist assessment, while some chronic leukaemias can be monitored or controlled with tablets. The exact subtype can change both how quickly treatment needs to start and which treatment is most appropriate. [1–6]
By Dr Raman Narang, Consultant Medical & Hemato-Oncologist, New Delhi
A raised white blood cell count can start an investigation, but it cannot tell you on its own which type of leukaemia you have or whether you need treatment. A person with chronic lymphocytic leukaemia may be monitored for years, while someone with suspected acute promyelocytic leukaemia needs emergency care that day. If you are seeking leukaemia treatment in Delhi, ask your team for the exact subtype, which results are pending, and whether any decision needs to be made before those results return.
1. What are the symptoms of leukaemia?
Leukaemia can interfere with the bone marrow’s ability to make healthy blood cells. Anaemia can cause fatigue, breathlessness, or pallor. Low platelets can cause easy bruising, tiny red or purple spots, or bleeding from the gums or nose. A shortage of healthy infection-fighting cells can lead to fever or repeated infections. Some people also develop enlarged lymph nodes, bone pain, or a feeling of fullness under the left ribs from an enlarged spleen. Chronic leukaemia is sometimes found on a routine blood test before symptoms develop. [1, 2, 4, 6]
These symptoms have several possible causes. Fever in someone with known or suspected low neutrophils needs urgent assessment. Heavy bleeding, sudden breathlessness, or new confusion also requires emergency care. Bring the latest blood count and tell the treating team if a blood film has reported immature cells called blasts. [1–3]
2. How are leukaemias classified?
The first distinction is between acute and chronic leukaemia. Acute leukaemias generally progress quickly and involve immature cells. Chronic leukaemias often have a slower course, although they can progress and sometimes need prompt treatment. The second distinction is myeloid versus lymphoid, which describes the blood-cell lineage involved. [1–6]
| Main type | What distinguishes it |
|---|---|
| Acute myeloid leukaemia (AML) | A cancer of immature myeloid cells. Chromosome and gene findings can define the subtype, estimate relapse risk, and identify treatment options. Acute promyelocytic leukaemia (APL) is a distinct form of AML that needs an emergency treatment pathway. |
| Acute lymphoblastic leukaemia (ALL) | A cancer of immature lymphoid cells. It is classified into B-cell ALL and T-cell ALL, with further groups based on genetic findings. In B-cell ALL, finding BCR::ABL1, also called Philadelphia chromosome–positive ALL, changes treatment. |
| Chronic myeloid leukaemia (CML) | Defined by the BCR::ABL1 gene fusion. Most patients are diagnosed in chronic phase. Advanced disease can enter blast phase and needs a different approach. |
| Chronic lymphocytic leukaemia (CLL) | A cancer of mature B lymphocytes. Its tissue-based counterpart is called small lymphocytic lymphoma (SLL). Many patients who feel well and have stable disease can start with active monitoring. |
These are the four major types. Less common forms include hairy cell leukaemia and mixed-phenotype acute leukaemia. Modern classifications use the cells’ appearance, their markers, and their genetic findings together. That is why a final report may give a more specific name than the initial blood film. [1, 5, 6]
3. How is leukaemia diagnosed, and what does the risk classification mean?
A complete blood count (CBC) and peripheral blood film are often the first tests. The white blood cell count can be high, normal, or low, particularly in acute leukaemia. Depending on the suspected type, the team may also need a bone marrow sample, flow cytometry, and genetic tests. CLL can often be diagnosed from blood using flow cytometry, while AML and ALL commonly need bone marrow assessment to complete the work-up. [1, 2, 6]
| Test | What it helps the team decide |
|---|---|
| Flow cytometry | Identifies the markers on abnormal cells and helps distinguish AML, B-cell ALL, T-cell ALL, and mature lymphoid diseases such as CLL. |
| Chromosome and molecular testing | Can find changes that define a subtype or affect treatment. Examples include PML::RARA in APL, BCR::ABL1 in CML or some ALL, and FLT3 or NPM1 alterations in AML. |
| Measurable residual disease (MRD) testing | After treatment for certain acute leukaemias, sensitive tests can look for small amounts of leukaemia that routine microscopy may miss. Results can influence the next phase of treatment. |
| BCR::ABL1monitoring in CML | Regular molecular blood tests show how well treatment is controlling the disease, even after the blood count has returned to normal. |
Risk assessment is specific to the subtype. In AML, genetic risk and the response to treatment help estimate the chance of relapse and guide discussion about transplant. In ALL, lineage, genetic findings, and MRD are important. In CLL, tests such as TP53 mutation, deletion 17p, and IGHV status can help guide treatment selection when therapy is needed. An unfavourable genetic result alone does not mean that asymptomatic CLL needs immediate treatment. [1, 2, 4–6]
4. How are AML, APL, and ALL treated?
Acute myeloid leukaemia
For AML, the first treatment depends on the genetic subtype, how urgently the disease needs controlling, and how well the patient is likely to tolerate treatment. Some patients receive intensive chemotherapy, with a targeted drug added when an appropriate marker is present. Others may receive a lower-intensity regimen such as azacitidine plus venetoclax. After remission, further treatment is usually needed to reduce relapse risk. Options include consolidation treatment or a donor stem cell transplant for eligible patients, depending on genetic risk, response, and overall health. [1]
Acute promyelocytic leukaemia
Suspected APL is a medical emergency because severe bleeding can occur early. The hospital team generally starts all-trans retinoic acid (ATRA) as soon as APL is suspected, alongside measures to manage the clotting problem, while urgent testing for PML::RARA is underway. Once confirmed, treatment often includes ATRA and arsenic trioxide, with additional medicines in some higher-risk cases. [3]
Acute lymphoblastic leukaemia
ALL treatment is usually delivered in phases to achieve remission and reduce the risk of relapse. It includes treatment to protect the brain and spinal fluid. Age, fitness, and whether the disease is B-cell or T-cell ALL affect the regimen. A tyrosine kinase inhibitor (TKI) is part of treatment for Philadelphia chromosome–positive ALL. In certain cases of B-cell ALL, blinatumomab can be used. MRD results help guide further treatment, including whether transplant should be considered. [2]
Supportive care is part of acute leukaemia treatment from the start. It may include blood or platelet transfusions, infection treatment, and measures to prevent tumour lysis syndrome, which can occur when many leukaemia cells break down quickly. [1–3]
5. How are CML and CLL treated?
CML in chronic phase is usually treated with an oral TKI that blocks the activity of BCR::ABL1. The choice depends on the disease, other health conditions, side effects, and access. Regular BCR::ABL1 blood tests show whether the treatment is meeting its milestones. Selected patients with a sustained deep molecular response may eventually discuss a supervised attempt to stop treatment. This requires frequent testing and a clear plan for when to restart. [4]
CLL may be monitored when it is stable and causing no significant problems. Treatment may become appropriate if the disease causes worsening anaemia or low platelets, troublesome lymph node or spleen enlargement, or other signs of active disease. When treatment is needed, options often include a BTK inhibitor or a venetoclax-based regimen. The choice depends on TP53 findings, other medical conditions, previous therapy, and whether a fixed-duration or continuous regimen is suitable. [6]
What I look for clinically before recommending treatment
I review the blood film and the flow cytometry report together. If acute leukaemia is suspected, I first check for bleeding, infection, or another complication that needs attention that day. Then I identify which genetic results could change the first treatment and which will guide decisions later. For someone with chronic leukaemia, I explain whether the next step is monitoring or treatment, and which test will tell us whether that plan is working.
How the next step is decided
| If the reports show… | The next discussion is about… |
|---|---|
| Blasts suggesting acute leukaemia | Urgent specialist assessment, subtype testing, and immediate supportive care |
| Findings suspicious for APL | Emergency treatment while rapid genetic confirmation is underway |
| Confirmed AML or ALL | Which induction treatment fits the subtype and how response will be measured |
| CML in chronic phase | Which oral TKI is appropriate and when to check molecular response |
| CLL without symptoms or other treatment indications | The monitoring schedule and which changes would trigger treatment |
What to bring to a leukaemia consultation in Delhi
- Recent and previous CBC results and peripheral blood film reports.
- Bone marrow aspiration and biopsy reports, if performed.
- Flow cytometry, chromosome, FISH, PCR, or molecular testing reports.
- Dated MRD or BCR::ABL1 results, if available.
- Records of previous chemotherapy, targeted treatment, transplant, or transfusions.
- A list of current medicines, recent infections or bleeding, and other relevant medical conditions.
Frequently asked questions
Does a high white blood cell count mean I have leukaemia?
Infections, inflammation, medicines, and other conditions can also raise the count. The types of cells present, the blood film, and any further tests help establish the cause. [1, 4, 6]
Can leukaemia be cured?
Some acute leukaemias are treated with the aim of cure. Other types are commonly managed with long-term monitoring or treatment to control the disease. The exact subtype, genetics, and response are more informative than the diagnosis of leukaemia alone. [1–4, 6]
Does everyone with acute leukaemia need a stem cell transplant?
Transplant is considered in specific situations. The team reviews relapse risk, MRD, response to initial treatment, overall fitness, and the potential complications of transplant. [1, 2]
Why do I still need molecular tests if my blood count is normal?
A normal blood count shows that the numbers of circulating cells have recovered. Molecular testing can answer a different question. In CML, for example, it measures how much BCR::ABL1 remains and helps assess whether treatment is meeting its milestones. [4]
At your consultation, ask for the exact subtype, the urgency of treatment, and the result that will determine the next step. If a test is still pending, ask which decisions can be made now and which depend on that result.
This page is for general education. Individual treatment decisions require review of your blood counts, pathology, genetic results, symptoms, and overall health by your treating team.
Clinical references
- National Cancer Institute. Acute Myeloid Leukemia Treatment (PDQ). Health Professional Version.
- National Cancer Institute. Adult Acute Lymphoblastic Leukemia Treatment (PDQ). Health Professional Version.
- European LeukemiaNet. Management of Acute Promyelocytic Leukemia: Updated Recommendations From an Expert Panel of the European LeukemiaNet.
- European LeukemiaNet. 2025 European LeukemiaNet Recommendations for the Management of Chronic Myeloid Leukemia.
- World Health Organization. WHO Classification of Haematolymphoid Tumours. Fifth edition.
- National Cancer Institute. Chronic Lymphocytic Leukemia Treatment (PDQ). Health Professional Version.