中文摘要：

目的：探索提高难治性白血病患者的缓解率及生存率的改良方案。方法：运用延长的CHAG方案治疗4例难治性急性髓系白血病，观察疗效及不良反应。结果：4例难治急性髓系白血病患者经延长的CHAG方案治疗后，均获完全缓解，2例死亡，2例存活，其中1例生存时间大于1年。未出现严重感染、脏器功能受损及治疗相关死亡。结论：延长的CHAG方案能够提高难治性急性髓系白血病患者的缓解率，对于难治白血病患者可作为一个有效的选择。

英文摘要：

Objective： To explore a modified regimen which may improve complete remission rate and survival rate of patients with refractory leukemia. Methods ： The prolonged CHAG regimen was used to cure 4 patients with refractory acute myeloid leukemia in order to observe curative effects and adverse reactions. Results： Four patients with refractory acute myeloid leukemia undergoing prolonged CHAG regimen achieved complete remission. Two of them died, but the rest survived, and one of them has survived for more than one year. Severe infection was not observed. There were no chemotherapy-related mortality or organ dysfunction. Conclusion： Prolonged CHAG regi- men predicts a favorable curative effect with a high complete remission rate, and may be as an ef- fective choice to patients with refractory leukemia.