2. Extent of disease: remission (partial or complete) or smouldering course. Complete remission (CR) is defined as no blasts in the peripheral blood and no more than 5% blasts in the bone marrow. This definition is related to the hematological remission if it is not specified. Partial remission (PR) is defined as a decrease of at least 50% in the percentage of blasts to 5 to 25% in the bone marrow aspirate. Smouldering course is defined as a relatively low marrow blast count and slowly progressive disease.