Clinical characteristics of Japanese patients with t(8;21) acute myeloid leukemia (AML) have not been well described. From January 2000 to December 2005, a total of 147 Japanese adult de novo AML (FAB: M2) patients were newly diagnosed with t(8;21) AML (n=46) or without t(8;21) AML (n=101) in collaborating hospitals. Patients with t(8;21) (median age, 49.5 years; range, 18–86 years) were significantly younger than AML(M2) patients without t(8;21) (median age, 60 years; range 17–90 years) (p<0.001). Three-year overall survival rate in patients with t(8;21) was 70% (95% confidence interval (CI), 51–83%), significantly better than that in AML (M2) patients without t(8;21) (log-rank test, p=0.005) (Figure). Among patients <60-years-old, overall survival rates of patients with t(8;21) AML and patients with non-t(8;21) AML(M2) were 71% (95%CI, 47–86%) and 58% (95%CI, 41–72%), respectively (log-rank test, p=0.28). Of the 40 patients who achieved complete remission, 21 patients received high-dose cytarabine-containing consolidation therapy. Event-free survival rates at 3 years after diagnosis in patients with and without high-dose cytarabine were 60% (95%CI, 36–78%) and 57% (95%CI, 26–79%), respectively (log-rank, p=0.87). In multivariate analysis, age and white blood cell count at diagnosis represented significant predictors of overall survival. For the 147 AML(M2) patients, presence of t(8;21) was not a significant predictor of overall survival after adjusting for age (hazard ratio, 0.65; 95%CI, 0.34–1.24; p=0.19). Japanese patients with t(8;21) AML display more favorable survival rates than those in Western countries. Efficacy of high-dose cytarabine might differ between Japanese and Western patients. Clinicians must be aware of potential differences among different ethnicities.

Author notes

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