Testing Sokal's and the new prognostic score for chronic myeloid leukaemiatreated with alpha-interferon

As it has been shown that alpha -interferon (alpha IFN) treatment modifies the survival of chronic myeloid leukaemia (CML) patients in comparison with conventional chemotherapy, a new prognostic score was devised with the aim of providing a treatment-adapted risk evaluation. We have tested the new p rognostic score (the Euro score) in an independent series of 272 patients l ess than 56 years old with previously untreated, chronic phase, Philadelphi a (Ph)-positive CML who had been assigned prospectively to alpha IFN treatm ent between 1989 and 1991. The Sokal score system was used as a reference. The new Euro score predicted the response to alpha IFN as the Sokal score. The median survival of low-risk, intermediate-risk and high-risk patients w as similar using the Euro score (105, 65 and 45 months) and Sokal score (10 5, 76 and 45 months) but, by multivariate analysis, the Euro was more poten t than Sokal for predicting survival time. The new Euro score identified mo re low-risk cases (59% vs. 48%) and fewer high-risk cases (9% vs. 23%) than the Sokal score. The main differences between the Euro and Sokal scores co ncerned age (it is more important in the Euro than in Sokal), spleen size a nd the percentage of myeloblasts in peripheral blood (more important in Sok al than in Euro). We conclude that the new Euro score marks an improvement in the prognostic evaluation of CML treated with alpha IFN. By comparison w ith the Sokal score, the Euro was more potent and identified more low-risk patients but left only a small number of cases in the high-risk group.