Peripheral erythroid precursor and prognosis in chronic granulocytic leukemia.

Seventy-four consecutive patients with nonblastic chronic granulocytic leukemia (CGL) were observed from diagnosis and retrospectively studied. The patients were segregated into three risk groups according to the staging system proposed by Sokal et al. A significant difference in survival was observed only between Stage I and III (P = 0.01). The prognostic role of other variables, different from those considered in the Sokal et al. equation, was then investigated. Multiple regression analysis of data was made, by forcing into the Cox's regression model the Sokal et al. equation, while allowing the remaining variables to move in and out of the model. Only the presence of peripheral nucleated erythrocytes improved the significance (chi-square improvement = 4.565; P value improvement = 0.033). The evaluation of peripheral erythroid precursors is proposed for further implementation of the staging systems in CGL.