目的 探讨聚乙二醇化重组人粒细胞刺激因子（pegylated recombinant human granulocyte col⁃ony⁃stimunating factor，PEG⁃rhG⁃CSF）预防老年消化道肿瘤患者化疗后中性粒细胞（absolute neutrophil count，ANC）减少的临床效果。方法 本研究共纳入47 例消化道肿瘤患者，在化疗第一周期的第3 天给予6 mgPEG⁃rhG⁃CSF 皮下注射，若出现ANC减少，则在化疗第二个周期继续给予6 mg PEG⁃rhG⁃CSF 皮下注射，若未出现ANC 减少，则在化疗第二个周期给予3 mg PEG⁃rhG⁃CSF 皮下注射。结果 化疗第一周期、化疗第二周期3 mg PEG⁃rhG⁃CSF、化疗第二周期6 mg PEG⁃rhG⁃CSF后ANC减少症的发生率分别为19.1%、31.6%、55.6%（P＜0.05）；三者之间的ANC减少症持续时间比较差异无统计学意义（P＞0.05）。化疗第一周期、化疗第二周期3 mg PEG⁃rhG⁃CSF、化疗第二周期6 mg PEG⁃rhG⁃CSF 的FN 发生率分别为4.3%、7.9%、11.1%，差异无统计学意义（P＞0.05）。研究期间有2例出现骨痛、1例出现乏力、1例出现肌肉疼痛，不良反应总发生率为8.5%。结论 化疗期间使用PEG⁃rhG⁃CSF 可有效预防老年消化道肿瘤患者化疗后中性粒细胞减少的发生，且安全性较好。

Objective To explore the clinical effect of pegylated recombinant human granulocyte stimulat⁃ing factor（PEG⁃rhG⁃CSF）in the prevention of neutropenia after chemotherapy in elderly patients with gastrointesti⁃nal cancer. Methods A total of 47 patients with digestive tract tumors were included in this study. They weregiven a subcutaneous injection of 6 mg PEG⁃rhG⁃CSF on the third day of the first cycle of chemotherapy. If ANCdecreased，they were given subcutaneous injection of 6 mg PEG⁃rhG⁃CSF on the second cycle of chemotherapy. IfANC did not decrease，they were given a subcutaneous injection of 3 mg PEG⁃rhG⁃CSF on the second cycle of che⁃motherapy. Results In the first cycle of chemotherapy，the second cycles of chemotherapy with 3 mg PEG⁃rhG⁃CSFand the second cycles of chemotherapy with 6 mg PEG⁃rhG⁃CSF，the incidence of FN was 19.1%，31.6% and 55.6%（P＜0.05）. There was no significant difference in duration of ANC reduction in the three groups（P > 0.05）. In thefirst cycle of chemotherapy，the second cycles of chemotherapy with 3 mg PEG⁃rhG⁃CSF and the second cycles ofchemotherapy with 6 mg PEG⁃rhG⁃CSF，the incidence of FN was 4.3%，7.9% and 11.1%，which was no significantdifference（P > 0.05）. During the study period，there were 2 cases with bone pain，1 case with asthenia and 1 casewith muscle pain. The total incidence of adverse reactions was 8.5%. Conclusion PEG⁃rhG⁃CSF can effectivelyprevent neutropenia in elderly patients with gastrointestinal cancer，and it has high safety.