Staging of chronic myeloid leukaemia.
The prognostic value of nine clinical and haematological features, recorded at diagnosis in chronic myeloid leukaemia (CML), was analysed in two distinct series of patients. One series (116 cases) was collected at a single hospital over a 12-year period. The second series (139 cases) was collected from a multicentre trial over a 20-month period. Six features were associated with a poor prognosis: splenomegaly (more than 15 cm below the costal margin), hepatomegaly (more than 6 cm below the costal margin), thrombocytopenia (< 150 X 10(9)/l) or thrombocytosis (> 500 X 10(9)/l), a leucocyte count above 100 X 10(9)/l, peripheral blood non-granulated precursors (blast cells) above 1%, and peripheral blood granulated precursors (promyelocytes and myelocytes) above 20%. Depending on the number of negative prognostic factors, patients were divided into three categories: group I (0 or 1 factor), group II (2 or 3 factors) and group III (4,5 or 6 factors). Survival was significantly different in the three groups (P < 0.0005), and this was independent of age (below and above 50). The prognostic value of the classification was confirmed in a third series of 153 patients. We suggest that this classification provides a useful tool to identify prognostic categories in CML, and thus allows a proper allocation of patients to different therapies.