目的:研究DNA双链断裂（DNA double-strand breaks，DSB）修复能力的影响因素及其与分化型甲状腺癌（DTC）发生风险的关系。方法:回顾性分析河南省肿瘤医院2020年1月至3月收治的140例甲状腺疾病患者，其中男性26例，女性114例，年龄18~78岁。依据病理结果将患者分为DTC组（90例）与对照组即甲状腺良性结节（benign thyroid nodules，BTN）组（50例），应用流式细胞仪测定所有患者外周血T淋巴细胞的DSB修复能力，通过Wilcoxon秩和检验对2组数据进行比较，评估DSB修复能力与DTC发生风险的关系。并根据BTN组DSB修复能力中位数将DSB修复能力分为高和低2组，采用Logistic 回归法对可能影响DSB修复能力的因素进行分析。采用SPSS 22.0软件对数据进行统计学分析。结果:DTC组的DSB修复能力中位数为27.87%，BTN组中位数为36.75%，DTC组的DSB修复能力低于BTN组，差异有统计学意义（n Z=-3.999，n P<0.05）；通过Logistic 回归分析发现DTC患者比BTN患者的DSB修复能力低（n OR=2.245，95%n CI：1.067~4.725，n P=0.033），有辐射暴露史的人群DSB修复能力降低（n OR=2.698，95%n CI：1.271~5.725，n P=0.010）。n 结论:DSB修复能力较低的人患DTC的风险可能增加，辐射暴露可能是DSB修复能力降低的危险因素。“,”Objective:To study the influencing factors of DNA double-strand breaks (DSB) repair capacity and relationship with differentiated thyroid cancer (DTC).Methods:A total of 140 patients with thyroid diseases admitted to the Henan Cancer Hospital from January 2020 to March 2020 were retrospectively analyzed, including 26 males and 114 females, aged from 18 to 78 years old. According to the pathological results, the patients were divided into DTC group (90 cases) and control group or benign thyroid nodules (BTN) group (50 cases). The DSB repair ability of peripheral blood T lymphocytes was measured by flow cytometry. The data of two groups were compared by Wilcoxon rank sum test to evaluate the relationship between DSB repair ability and the risk of DTC. According to the median repair ability of DSB in BTN group, the repair ability of DSB was divided into high and low categories, and the factors influencing the repair ability of DSB were analyzed by Logistic regression method. SPSS 22.0 software was used to analyze the data.Results:The DSB repair capacity was 27.87% in DTC group and 36.75% in BTN group, with significant difference (n Z=-3.999,n P<0.05). Logistic regression analysis suggested that patients with thyroid cancer had lower DSB repair capacity than patients without cancer (n OR=2.245; 95%n CI: 1.067-4.725; n P=0.033), and patients with a history of radiation exposure had a reduced DSB repair capacity (n OR=2.698; 95%n CI: 1.271-5.725, n P=0.010).n Conclusion:The risk of DTC increases in patients with low DSB repair capacity. Radiation exposure is a risk factor for the reduction of DSB repair capacity.