Determinants of prognosis in late chronic-phase chronic myelogenous leukemia

Purpose: Since interferon alfa (IFN-A) became an established treatment in c hronic myelogenous leukemia (CML), more patients are referred to tertiary c enters in late chronic phase (ie, > 12 months after diagnosis). Trials cond ucted in this phase cannot be evaluated precisely unless the features that determine prognosis in late chronic-phase CML are identified. The purpose o f this study is to define the prognostic determinants of late chronic-phase CML. Patients and Methods: From 1980 to 1997, 257 consecutive CML patients refer red in late chronic phase were studied. Their clinical characteristics at t he time of referral and their association with survival were investigated. A staging model was designed. Results: The median survival from time of referral was 43 months. Pretreatm ent characteristics associated with worse outcome included older age, poor performance status, splenomegaly, low albumin level, high percentage of bla sts or basophils in peripheral blood (PB) or bone marrow, longer duration o f chronic phase, and poor-risk group as defined by the Synthesis model. out come. By multivariate analysis, characteristics associated with shorter sur vival were age of 60 years or older, time from diagnosis of 3 years or grea ter, performance status of 1 or greater, PB basophils of 7% or greater, spl een 10 cm or greater, PB blasts 3% or greater, and albumin level less than 4 g/dL, A model that included age, duration of: chronic phase, performance status, and PB basophils was generated. Patients with no, one, two, or thre e or greater adverse factors had median survivals of 71, 49, 26, and 19 mon ths, respectively. Conclusion: A staging model for late chronic-phase CML can stratify patient s in four groups with significantly different outcomes. If confirmed in ind ependent populations, such a model could be considered in the analysis of f uture trials of treatment strategies in late chronic-phase CML. (C) 1998 by American Society of Clinical Oncology.