Utility of interphase FISH to stratify patients into cytogenetic risk categories at diagnosis of AML in an Eastern Cooperative Oncology Group (ECOG) clinical trial (E1900)

We evaluated the efficacy of FISH to detect chromosome anomalies in the evaluation of young (<60 years) patients with AML. Patients were enrolled in E1900, an ECOG clinical trial for AML. The protocol was designed to collect bone marrow or blood for both cytogenetic and FISH studies at study entry (diagnosis). FISH for each patient was performed and utilized eight probe sets to detect t(8;21), t(9;22), t(11;var), t(15;17), inv(16), +8, -5/5q, and -7/7q. We analyzed 237 specimens with complete cytogenetic and FISH results. Results for each specimen were classified by probe set into one of six categories. The concordance rate between cytogenetic and FISH results ranged from 98 to 100% for all probe sets and kappa analysis for concordance had a p-value of <0.0001. The high level of agreement between cytogenetic and FISH results demonstrate the accuracy of a panel of eight FISH probe sets for the detection of significant abnormalities in AML. Data from this investigation support the use of FISH as an adjunct method to increase the yield of useful cytogenetic results in large cooperative trials and demonstrate the potential of FISH as a follow-up study of minimal residual disease in ECOG trials.