Dr. Sandeep Ramawat
Cancer Insights

What Is CML?

Chronic myeloid leukaemia behaves differently from most cancers, and from most other leukaemias. Understanding why starts with a single genetic change.

In summary

Short answer: CML is a chronic blood cancer caused by a genetic change that creates the BCR-ABL fusion gene, which drives overproduction of white blood cells. Because that single driver is well understood, CML is usually treated with oral targeted therapy rather than chemotherapy.

What happens in CML

Short answer: In CML, a piece of chromosome 9 and a piece of chromosome 22 swap places. The result, often called the Philadelphia chromosome, creates a fusion gene named BCR-ABL that produces an abnormal protein. That protein behaves like a switch stuck in the on position, telling the bone marrow to keep producing white blood cells. The cells that accumulate are relatively mature, which is part of why the disease is called chronic and why many people feel well at diagnosis.

How CML differs from acute leukaemia

Acute leukaemias develop quickly and usually need treatment to begin within days. CML typically develops slowly, and a substantial number of patients are diagnosed incidentally on a blood count done for another reason. The treatment approach differs just as sharply: acute leukaemia generally requires intensive chemotherapy, whereas chronic phase CML is usually managed with a daily oral tablet taken at home.

Why one genetic change made such a difference

Because CML is driven by a single, identifiable abnormality, it became one of the first cancers where a drug could be designed to block the specific faulty protein rather than attacking dividing cells in general. That is the reason CML is often used as the textbook example of targeted therapy, and it is why the day-to-day experience of treatment looks so unlike what most people picture when they hear the word leukaemia.

What symptoms can occur

Many people have no symptoms at all. Where symptoms do occur they tend to be non-specific and gradual: tiredness, unintended weight loss, night sweats, a feeling of fullness or discomfort under the left ribs from an enlarged spleen, or easy bruising. Because these overlap with many ordinary conditions, CML is frequently picked up first as an unexplained high white cell count on a routine blood test.

Where this fits in treatment

For the full clinical overview, see CML treatment in Gurugram. If you are weighing a treatment decision, a second opinion reviews the diagnosis and the plan together.

Questions

Related questions

CML accounts for a minority of adult leukaemias. It is uncommon, but it is one of the better understood blood cancers because it is driven by a single identifiable genetic change.

The BCR-ABL change in CML is acquired during a person’s lifetime rather than inherited from a parent, and it is not passed on to children.

About this article. Written by Dr. Sandeep Ramawat, Medical & Hemato-Oncology Specialist. General information consistent with guidance from the European Society for Medical Oncology and the US National Cancer Institute. This article is general information and cannot replace a consultation. See the full disclaimer.

Speak to Dr. Ramawat

Dr. Ramawat currently consults at the American Oncology Institute, Gurugram. Call directly or send your details on WhatsApp.