UNDERESTIMATION OF INVERSION (16) IN ACUTE MYELOID-LEUKEMIA USING STANDARD CYTOGENETICS AS COMPARED WITH POLYMERASE CHAIN-REACTION - RESULTS OF A PROSPECTIVE INVESTIGATION

In order to determine whether the polymerase chain reaction (PCR) is m ore suitable for the detection of inversion (16) as compared with stan dard cytogenetics, we prospectively investigated a total of 132 cases of de novo acute myeloid leukaemia (AML) (n=121) and secondary AML aft er myelodysplastic syndromes (MDS) (n=11) using a sensitive and nested PCR procedure to detect the fusion transcripts CBF beta-MYH11. All pa tients were recruited within 10 months in an ongoing multicentre AML-t rial. In addition, several cases from a retrospective molecular analys is were included, The data were compared with standard cytogenetics pe rformed in a central laboratory. Of the 132 prospective AML cases, fiv e patients (3.7%) harboured inv(16) upon conventional cytogenetics. In all cases fusion transcripts CBF beta-MYH11 were detected using PCR. In addition in two patients fusion transcripts were detected, although cytogenetics revealed a normal karyotype. In the group of patients an alysed retrospectively, four patients harboured fusion transcripts spe cific for CBF beta-MYH11: cytogenetics were normal in one case, and co uld not be evaluated in two cases, These data show that PCR may be a b etter means to detect inv(16) in AML, Since inv(16) may have prognosti c impact in AML, detection of this aberration seems important in the c linical management of AML patients.