Polycythemia vera: the natural history of 1213 XXXX followed for 20 years. Gruppo Italiano Studio Policitemia.

@entity1 @entity6582 @entity64 @entity5 @entity6961 @entity1150 @entity1583 @entity583 @entity204 @entity715
OBJECTIVE: To reassess the natural history of @entity6582 vera and to obtain reliable estimates of both incidence of @entity715 and survival for use in defining the sample size for therapeutic clinical trials. STUDY DESIGN: Retrospective cohort study of @entity1 with @entity6582 who had been followed for 20 years. SETTING: 11 Italian hematology institutions. @entity1 : 1213 @entity1 with @entity6582 vera, which was diagnosed according to criteria established by the Polycythemia Vera Study Group and commonly used in clinical practice. MAIN OUTCOME MEASURES: All-cause mortality, venous and arterial @entity715 , and hematologic and nonhematologic @entity5 . @entity583 and @entity64 were classified as major @entity715 events, and venous and peripheral arterial @entity715 were considered minor @entity715 events. The number of @entity1 who died and the number of those who had major @entity715 events (combined end point) were used as a comprehensive measure of the benefit-risk ratio associated with the use of myelosuppressive agents. RESULTS: 634 fatal and nonfatal arterial and @entity1150 were recorded in 485 @entity1 (41%); 36% of these episodes occurred during follow-up in 230 @entity1 (19%), and 64% occurred either at presentation or before diagnosis. @entity715 events occurred more frequently in the 2 years preceding diagnosis, suggesting a causal relation between the latent @entity6961 and the vascular event. The incidence of @entity715 during follow-up was 3.4%/y; older @entity1 or those with a history of @entity715 had a higher risk for @entity715 . Overall mortality was 2.9/100 @entity1 per year; @entity715 events and @entity1583 had similar effects on mortality. @entity1 receiving chemotherapy died three to four times more frequently than those not receiving chemotherapy. The increased risk for @entity5 in @entity1 receiving myelosuppressive agents was seen approximately 6 years after diagnosis. In addition, the combined end point, computed as the sum of the hardest available events ( @entity204 , nonfatal @entity583 , or @entity64 ), suggests that myelosuppressive agents have an overall unfavorable effect. CONCLUSIONS: Cytoreduction favorably affects the incidence of @entity715 events, but aggressive treatment seems to be associated with increased risk for @entity5 . These results provide a basis for reevaluating the therapeutic strategy in @entity1 with @entity6582 vera and for estimating the size of clinical trials aimed at testing new therapeutic approaches.
