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Questions and answers

Questions about CML

Chronic myeloid leukemia (CML) is one of the leukemias that has changed most in recent decades: many people now live with it for many years.

Last updated: ~1 min read
How the Philadelphia chromosome forms
Figure 1.How the Philadelphia chromosome forms

01Short answer

CML is a chronic leukemia in which myeloid cells multiply slowly. It is caused by the Philadelphia chromosome and a fused gene called BCR::ABL1, which constantly tells the cell to divide. Targeted drugs called tyrosine kinase inhibitors (TKIs) block this signal. Most patients are diagnosed in the chronic phase, and with regular medicine the disease stays under control for a long time. The effect of treatment is tracked with a PCR test that measures BCR::ABL1 in the blood.

02Simple explanation

In CML the cells have a “broken switch” called BCR::ABL1, so they keep dividing.

TKI medicines turn this switch off.

03Scientific explanation

CML is described in three phases: chronic, accelerated and blast phase (newer classifications have reduced the role of the accelerated phase). With modern treatment most patients stay in the chronic phase.

Molecular response is measured on the International Scale (IS); some patients with a deep, lasting response can stop treatment under strict monitoring (treatment-free remission).

04What happens in the body?

How it is diagnosed

Often a routine blood test shows a high white cell count. Bone marrow and genetic tests (cytogenetics, FISH, PCR) then confirm the Philadelphia chromosome.

How treatment works

TKIs are usually tablets taken every day. Side effects differ between drugs and are often manageable. Never stop the medicine or change the dose on your own.

A daily medicine routine
Figure 2.A daily medicine routine

Monitoring

PCR tests are done regularly. If targets are not met, the doctor may switch drugs or test for mutations.

Molecular response: the level falls
Figure 3.Molecular response: the level falls

05The path in CML

The main stages.

BCR::ABL1 found — Genetic tests confirm the diagnosis.1BCR::ABL1 foundGenetic tests confirm the diagnosis.
A daily TKI — The targeted drug is taken every day.2A daily TKIThe targeted drug is taken every day.
PCR monitoring — The depth of response is measured.3PCR monitoringThe depth of response is measured.
Long-term control — The disease is managed for years.4Long-term controlThe disease is managed for years.
ConsistencyNo missed doses protects the result.
Regular PCRTests track the response.

06Key points at a glance

TopicIn brief
How it is diagnosedOften a routine blood test shows a high white cell count. Bone marrow and genetic tests (cytogenetics, FISH, PCR) then confirm the Philadelphia chromosome.
How treatment worksTKIs are usually tablets taken every day. Side effects differ between drugs and are often manageable. Never stop the medicine or change the dose on your own.
MonitoringPCR tests are done regularly. If targets are not met, the doctor may switch drugs or test for mutations.

07Key terms

Philadelphia chromosome
A change caused by chromosomes 9 and 22 swapping pieces.
TKI
Tyrosine kinase inhibitor, a drug that blocks BCR::ABL1.
Molecular response
A fall in BCR::ABL1 levels on PCR.

08Key points

  • CML is caused by BCR::ABL1.
  • TKIs keep the disease under control.
  • PCR tracks treatment.
  • Taking the medicine without gaps matters.

09Frequently asked questions

What if I miss a day of my TKI?

Tell your team; frequent missed doses can worsen the result.

Can I stop treatment?

Only on your doctor’s decision and with strict PCR monitoring.

Can I work with CML?

Many people work and live ordinary lives.

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.

  1. What if I miss a day of my TKI?

  2. Can I stop treatment?

  3. Can I work with CML?

My questions

12Sources

  1. National Cancer Institute (NCI). Chronic Myeloid Leukemia Treatment (PDQ®) – Patient Version
  2. NHS. Chronic myeloid leukaemia
  3. MedlinePlus (U.S. National Library of Medicine). Leukemia
  4. National Cancer Institute (NCI). Leukemia—Patient Version
  5. Anthony Nolan. Understanding stem cell transplants
  6. National Cancer Institute (NCI). Questions to Ask about Cancer Treatment
  7. American Cancer Society. Typical Treatment of Acute Lymphocytic Leukemia
  8. National Cancer Institute (NCI). Side Effects of Cancer Treatment
  9. National Cancer Institute (NCI). Bleeding and Bruising (Thrombocytopenia) and Cancer Treatment
  10. NHS (UK). Acute myeloid leukaemia
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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