Breakpoint localization within the M-bcr and clinical course do not correlate in patients with chronic myelogenous leukemia undergoing alfa interferon therapy.

The breakpoint localization was analyzed in 61 patients with Philadelphia chromoeome (Ph) positive chronic myelogenous leukemia to compare the breakpoint localization and clinical course. All patients were treated with interferon alfa (IFNα) or IFNα plus IFNγ at the time of the study. Thirty-three of the patients had been pretreated with other cytoetatic drugs. Sixty-nine per cent of the breakpoints were located in the 5'region of the major breakpoint clueter region (M-bcr), 29% in the 3'part