Abstrakt
We read with interest an updated analysis of TEL/AML1 incidencein relapsed ALL patients by Seegeret al.Several reports have been published recently concerning the issue of prognostic impact of TEL/AML1. However, none of the major studies disputed better out-come of TEL/AML1-positive patients.2-4In this respect, disturbing phenomenon emerged in retrospective studies on relapsed ALL.
Not only do the TEL/AML1-positive leukaemias relapse but in some studies their relapse rate appears to be unexpectedly high. Prospective studies based on large cohorts of patients will contribute to disclosure of a real clinical significance of TEL/AML1 fusiongene.
The major drawback of retrospective studies resides in a possible selection bias due to low availability of samples from a defined population.