M-BCR breakpoint location does not predict survival in Philadelphia chromosome-positive chronic myeloid leukemia

Some reports in the recent literature have shown that the site of molecular rearrangement within the M-BCR area may have a prognostic value in Ph1 + CML patients. A number of studies have, however, failed to demonstrate this finding. Here we report the molecular rearrangements of 107 patients and their clinical follow-up.

Localization of the breakpoints was determined according to conventional criteria, after digestion with 2 to 4 restriction endonucleases and hybridization with 1 or 2 molecular probes.

Sixty two patients were rearranged in the 5' area and 45 in the 3' area: there was no difference between the survival curves of the two groups, at least not after 3 years of follow-up.

The site of the breakpoint within the M-BCR has no prognostic significance in our series.