Karyotypic change between diagnosis and relapse as a predictor of salvage therapy outcome in AML patients

BACKGROUND: Only a few patients who experience AML relapse derive lasting benefit from re-induction therapy. The utility of reassessing the disease karyotype at relapse is unclear. The main goals of this study were to identify prognostic factors for AML relapse and to determine the prognostic utility of karyotypic change between diagnosis and relapse as a variable for predicting response to salvage therapy for relapsed AML. METHODS: This retrospective study included 58 patients with relapsed AML treated at the Yonsei University College of Medicine between 2005 and 2010. Karyotypes at both diagnosis and relapse were available for 45 patients (77%). A change in karyotype at relapse was observed in 17 of 45 cases (37%), and no change was noted in 28 of 45 cases (62%). RESULTS: Karyotypic changes between diagnosis and relapse were associated with the response rate (RR) to salvage therapy (P=0.016). Overall survival (OS) and event-free survival (EFS) in the group with karyotypic changes between diagnosis and relapse were significantly different from those with no karyotypic changes (P=0.004 and P=0.010, respectively). We applied multiple multivariate Cox regression analyses to identify independent prognostic factors for overall response (OR), OS, and EFS. A change in karyotype between diagnosis and relapse was significantly associated with OS (P=0.023; RR=2.655) and EFS (P=0.033; RR=2.831). CONCLUSION: Karyotypic changes between the diagnosis and relapse of AML could be used to predict outcomes and tailor clinical and biological therapeutic strategies for relapsed AML patients.