As soon as the diagnosis is confirmed, treatment is started.
Risk assessments tied to the expected disease outcome, treatment, and probability for reaching the treatment goal with the treatment alternatives, is central to handling of the patient.
The disease phase, age, thrombocyte count, spleen size, and number of blasts in peripheral blood are risk factors forming the basis for separating patients into the following prognosis groups:
- high risk of progression
- intermediary risk for progression
- low risk for progression
Individual treatment plans should be made. Good objective information and patient involvement in decisions where uncertainty is the greatest is very important.
Cytogenetic changes such as deletions on the derivative chromosome 9 and other cytogenetic changes in the Ph+ clone are negative prognostic indicators. This data is important for what strategy is chosen at the time of diagnosis and for sub-optimal response to treatment.
Monitoring the disease
Chronic myeloid leukemia and its treatment effect can be monitored on three levels:
- Leukocytes < 10 x 109/l
- Thrombocytes < 450 x 109/l
- < 5 % myelocytes in blood
- No blasts or promyelocytes in blood
- < 20 % basophile granulocytes in blood
- No extramedullary manifestations
- Complete cytogenetic response (CCyR) – 0 % Ph+
- Partial cytogentic reponse (PCYR) – 1-35 % Ph+
- Major cytogenetic response (MCyR) – PCyR + CCyR (0-35 % Ph+)
- Minor cytogenetic response – 36-65 % Ph+
- Minimal cytogenetic response – 66-95 % Ph+
Cytogenetic response and the amount of bone marrow cells which are Ph+ are examined by freezing mitogen-stimulated cells in metaphase. At least 20 metaphases (cell divisions) should be examined.
- Complete – BCR-ABL transcript not detectable
- Major – BCR-ABL transcript ≤ 0,1%
PCR techniques measure BCR-ABL in the blood as a percent of the total ABL transcript. One hundred percent is the average of BCR-ABL transcript divided by the total ABL transcript x 100 in a reference population on 30 newly diagnosed CML patients. A result of 0.1% equals a 1000 fold reduction (3 log) of the transcript amount in relation to the reference population's average value and is expressed as "major molecular response." The concept "complete molecular response" in practice means the level is below the method's level of detection, which is usually reached by a 4-5 fold reduction of the BCR-ABL transcript.
The degree of cytogenetic and molecular response at a given point in time has shown to be a very good surrogate marker for progression-free survival.