Unsuccessful diagnostic cytogenetic analysis is a poor prognostic feature in acute myeloid leukaemia

Abstract

Chromosome banding analysis is the gold standard method for the identification of recurrent cytogenetic abnormalities in acute myeloid leukaemia (AML). It allows stratification of AML patients into subgroups with distinct responses to therapy and survival. Unfortunately, a variety of issues hamper cytogenetic evaluation in c. 10% of cases [unsuccessful cytogenetics (UC)] and the outcome of these patients is poorly understood. To better define the significance of UC in patients with AML, we compared the baseline characteristics and the prognostic impact of 94 (6%) patients, whose standard metaphase analysis yielded unacceptable results, to the remaining 1403 AML patients with successful cytogenetic analysis treated on successive Southwestern Oncology Group protocols. The incidence of UC increased with age, with peak incidence in patients older than 60 years. These patients had a lower response rate to induction chemotherapy (complete remission rate of 43%) and dismal 5-year survival rates (16%), which was especially poor in patients older than 60 years (<5%). The complete remission and survival rates were similar to those seen in patients with unfavourable karyotype. The early death rate was not increased. These results suggest that UC increases with age and predict for poor outcomes, similar to the outcomes of patients with unfavourable karyotype.

Trial registration: ClinicalTrials.gov NCT00004217 NCT00023777 NCT00085709 NCT00899171 NCT00899743 NCT01059734 NCT01338974 NCT01360125.

Keywords: acute myeloid leukaemia; karyotype; overall survival; unfavourable karyotype; unsuccessful metaphase analysis.

© 2013 John Wiley & Sons Ltd.

Figures

Figure 1

Five-year overall survival Kaplan-Meier plots according to revised cytogenetic risk category definition Legend: The cytogenetic risk classification has been previously described by SWOG.5 In brief, it compares the survival outcomes of patients with unsuccessful cytogenetics (magenta dashed) with those in previously described subgroups, including favorable (black solid), intermediate (orange dashed), unknown (green dashed), unfavorable (navy dashed), very unfavorable (light blue dashed).