Correlation Between BCR-ABL Expression and Tumor Burden is Restricted to the Transition from Minor to Major Cytogenetic Response in Interferon Treated CML Patients

A pre-Gleevec study

László KERESKAI, János A VASS, Mária KNEIF, László PAJOR

Department of Pathology, University of Pécs, Faculty of Medicine, Pécs, Hungary


The interferon treatment of chronic myeloid leukaemia has been monitored by investigating the tumour burden as revealed by fluorescence in situ hybridization and the expression of BCR-ABL chimera determined by quantitative reverse transcription polymerase chain reaction. These parameters were obtained from the peripheral blood of 51 untreated and 104 follow-up patient samples. Poor corrrelation (r=0.31) was found between BCR-ABL expression and tumor load in all samples as well as in untreated patients, and this correlation was even less in all follow-up cases (r=0.28). Regarding chimera expression five order of magnitude difference existed in the untreated patients and this value dropped to two in those with complete cytogenetic response. Only the major and the complete cytogenetic response groups differed significantly (p<0.001) in the BCR-ABL expression from that of patients at diagnosis. Among the different cytogenetic response groups the only significant difference (p<0.01) in the BCRABL expression was obtained between the major and the minor responders. In the individual patients not only correlated changes of residual tumour mass and chimera expression, but mainly independent changes of these two parameters were observed. This indicates that the BCR-ABL expression and the tumor burden are largely independent variables. Pathology & Oncology Research, Vol 9, Nr 3, 174-179, 2003

Key words: chronic myeloid leukaemia; molecular monitoring; quantitative polymerase chain reaction; fluorescence in situ hybridisation

Received: Aug 1, 2003; accepted: Sep 15, 2003
Correspondence: László PAJOR, Department of Pathology, University of Pécs, Faculty of Medicine, 12 Szigeti Str Pécs H-7624, Hungary; Tel: +36 72 536-282, Fax: +36 72 536-281; E-mail:

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