Overview

Chronic myelogenous leukemia (CML) is rare form of cancer that occurs in the bone marrow. Bone marrow is a tissue that has texture of a sponge located inside the bones where blood cells are produced. The development of CML results in an increased number of white blood cells in the blood.

CML is a type of disease that develops gradually. The disease impacts on elders and rarely occurs in children. The advancement of treatments has a high chance for patients with chronic myelogenous leukemia to recover. Majority of the patients have more prospective for remission and prolonged life after being diagnosed.

Chronic myelogenous leukemia is also known as chronic myeloid leukemia and chronic granulocytic leukemia.

Symptoms

Chronic myelogenous leukemia is usually asymptomatic. The disease could be found during a blood test. Once it has been detected, the following symptoms may occur:

  • Fever
  • Bone pain
  • Bruising or easy bleeding
  • Appetite loss
  • Feeling tired
  • Unintentional weight loss
  • Pain or fullness below the ribs on the left side
  • Night sweats

Causes

Chronic myelogenous leukemia develops when there is a malfunction of genes of bone marrow cells.

An abnormal chromosome develops. Normal human cells have 23 pairs of chromosomes. These chromosomes have DNA that consists of genes which control the cells in the body. When chronic myelogenous leukemia occurs, the chromosomes switch their sections with each other. When one section of chromosome 9 swaps its place with a section of chromosome 22, an extra-short chromosome 22 (Philadelphia chromosome) and extra-long chromosome 9 are produced. The extra-short chromosome 22 exists in the blood cells of 90% of patients with chronic myelogenous leukemia.

Chromosome abnormality creates a new gene. The swapping of DNA between the chromosomes creates an oncogene named BCR-ABL. The BCR-ABL gene contains instructions telling the abnormal blood cell to produce too much of tyrosine kinase, which is the protein promotes certain blood cells to grow out of control.

New gene allows too many diseased blood cells. Blood cells arise in a sponge-like material contained inside the bones, called bone marrow. When bone marrow is functioning in a normal way, immature cells or blood stem cells are created within a control. These immature cells are then mature and transform into numerous types of blood cells throughout the body known as, red blood cells, white blood cells and platelets.

When chronic myelogenous leukemia occurs the BCR-ABL gene results in the tyrosine kinase that enables the growth of excessive number of white blood cells. The abnormal Philadelphia chromosome exists in almost of the cells. Unlike normal cells, white blood cells that are diseased are not produced and die. They accumulate by in mass and decrease the growth of healthy blood cells, destroying the bone marrow.  

Risk factors

  • Advanced age
  • Gender: Male
  • Exposure to radiation from radiation therapy

Having a family history of chronic myelogenous leukemia is not considered as a risk factor. The mutations that results in the development of the disease are not passed genetically. The mutation occurs after the child has born.

Chronic myelogenous leukemia (CML)