结直肠癌患者手术前后循环DNA水平的变化及其意义

Alteration of pre- and postoperative circulating DNA level in colorectal cancer patients and its significance

目的:探讨结直肠癌患者手术前后循环DNA水平的变化及其临床意义。方法:检测42例结直肠癌患者术前、术后3,14,30 d循环DNA水平,并检测同期14例健康体检者循环DNA水平作为对照。结果:结直肠癌患者术前循环DNA水平明显高于健康人[(92.25±46.88)ng/mL vs.(22.14±16.16)ng/mL](P<0.01);结直肠癌术前循环DNA水平在不同年龄、性别、肿瘤部位分组间差异无统计学意义(P=0.293,P=0.244,P=0.135)。结直肠癌患者术后3 d循环DNA水平达(114.95±62.41)ng/mL,较术前明显升高(P<0.01),但在术后14,30 d分别为(38.50±37.71)ng/mL与(31.69±41.48)ng/mL,明显低于术前(均P<0.01)。结论:循环DNA水平在结直肠癌患者中升高,且术后早期一过性进一步升高,随后明显下降。循环DNA水平有望成为结直肠癌术后监测肿瘤状态和评价疗效的标志物。

Objective： To investigate the alteration of circulating DNA level in colorectal cancer patients before and after surgery and its clinical significance. Methods： The circulating DNA levels in 42 patients with colorectal cancer were detected before and on 3, 14 and 30 d after surger）5 and the circulating DNA levels in 14 healthy subjects undergoing health maintenance examination during the same period were determined as control.Results： The preoperative circulating DNA level in colorectal cancer patients was significantly higher than that in healthy subjects [（92.25±46.88） ng/mL vs. （22.14±16.16） ng/mL] （P〈0.01）, and the preoperative circulating DNA level in colorectal cancer patients showed no significant difference between or among the groups stratified by age, sex and tumor location （P=0.293, P=0.244 and P=0.135）. In colorectal cancer patients, the circulating DNA level on postoperative day （POD） 3 reached （114.95±62.41） ng/mL, which was significantly higher than that before surgery （P〈0.01）, but on POD 14 and 30 it was （38.50±37.71） ng/mL and （31.69±41.48） ng/mL respectively, and both were significantly lower than that before surgery （both P〈0.01）. Conclusion： The circulating DNA level is elevated in colorectal cancer patients, and it is further increased transiently in early postoperative stage and then markedly decreased. It may probably be used as an indicator for postoperative tumor status and efficacy evaluation in these patients.