Chronic myeloid leukemia (CML) (synonyms: Atypical myeloid leukemia; Blast relapse in myeloid leukemia; CML [chronic myeloid leukemia] in complete remission; Chronic myelosis; Chronic granulocytic leukemia; Chronic granulocytic leukemia in complete remission; Chronic myelogenous leukemia; Chronic myeloid leukemia; Chronic myelocytic leukemia; Monocytic Naegeli leukemia; ICD-10-GM C92. 1: Chronic myeloid leukemia [CML], BCR/ABL-positive; incl.: Chronic myeloid leukemia, Philadelphia chromosome (Ph1) positive, Chronic myeloid leukemia, t(9;22) (q34;q11)) is a malignant neoplasm of the hematopoietic system (hemoblastosis) that occurs primarily in middle age.
CML a clonal myeloproliferative disorder characterized by translocation of the long arms of chromosomes 9 and 22, t(9;22)(q34;q11).In addition, myeloproliferative neoplasms (MPNs) (formerly chronic myeloproliferative disorders (CMPE)) include the following diseases:
- Essential thrombocythemia (ET) – chronic myeloproliferative disorder (CMPE, CMPN) characterized by chronic elevation of platelets (thrombocytes).
- Osteomyelofibrosis (OMF; synonym: osteomyelosclerosis, PMS) – myeloproliferative syndrome; represents a progressive disease of the bone marrow.
- Polycythaemia vera (PV, also called polycythemia or polycythemia) – rare myeloproliferative disorder in which all cells in the blood multiply excessively (particularly affected are erythrocytes (red blood cells), and to a lesser extent platelets (thrombocytes) and leukocytes – white blood cells).
Peak incidence: the peak of the disease is between 55 and 60 years of age.
De incidence (frequency of new cases) is 2:100,000 population per year.
CML often progresses with three phases of disease:
- Chronic phase – chronic stable phase (blast percentage at about 10%).
- Accelerated phase (acceleration phase) – transition between chronic phase and blast crisis (increase in the number of blasts, but remains below < 30%).
- Blast crisis – phase of the disease in which there is a crisis occurrence of immature white blood cells (blasts; promyelocytes) in the blood; develops in two-thirds of affected individuals (blast percentage in the blood > 30%).
The German CML Study Group defines blast crisis as follows:
- Proportion of blasts and promyelocytes in peripheral blood and/or bone marrow ≥ 30%, or
- Proportion of blasts and promyelocytes more than 50% of nucleated cells in bone marrow, or
- Cytologically or histologically confirmed blastic infiltrates outside bone marrow, spleen, or lymph nodes. Such infiltrates are also called chloromas.
The 10-year survival rate ranges from 40-88%.
In Sweden, the life expectancy of a CML patient newly diagnosed since 2013 almost reaches that of the normal population. A German study comes to the same conclusion: today, 83% of CML patients are still alive ten years after diagnosis.