分子标记物预测直肠癌新辅助放化疗效果初步评价

目的：寻找预测直肠癌新辅助治疗效果的分子标志物。方法：对26例行新辅助治疗的进展期中低位直肠癌的治疗前活检标本的K-ras基因进行测序，同时通过免疫组织化学方法对分子标志物增殖细胞核抗体（Ki-67）、核转录因子（NF-KB）、细胞周期蛋白依赖性激酶1（CDK1）进行检测。对手术标本行病理分析和肿瘤消退分级评估。结果：本组病例新辅助治疗后获得病理完全缓解（pCR）的患者7例（26．9％）均为K-ras基因野生型，治疗后降期患者17例（65．4％）。K-ras基因是否突变同新辅助放化疗（CRT）能否达到pCR密切相关（P=0．048）。K-ras基因野生型患者的降期率和肿瘤消退率均为77．8％（14／18），同突变型的降期率和肿瘤消退率比较P=0．063。结论：中低位直肠癌患者新辅助治疗前K-ras基因野生型可能预示着较好的新辅助治疗效果。

Biomarkers for response to preoperative chemoradiotherapy in patients with rectal carcinoma

Objective： To identify biomarkers for response to preoperative chemoradiotherapy in patients with rectal carcinoma. Methods： Twenty-six patients with mid-low rectal cancer underwent neoadjuvant before surgery were included in this study. For pretreatment tumor biopsies, K-ras was detected by Gene sequencing, Ki-67,NF-κB,CDK1 were detected by immunohistochemistry using specific antibodies. Pathology analysis and Tumor-regression grading were done after operation. Results： In this group, 7 cases （26.9%）got pCR after the neoadjuvant therapy and their K-ras were all wild type. Down-staging was achieved in 17 cases （65.4%）, K-ras gene muta- tion was relevant to pCR rate （P=0.048）. Down-staging rate and tumor-regression rate of patients with wild type K-ras gene were both 77.8% （14/18）, which were better than down-staging rate and tumor-regression rate of patients with mutated type K-ras gene （P = 0.063）. Conclusions： Our results demonstrate that wild type K-ras gene in pretreatment mid-low rectal carcinoma may be predictive of good tumor response to neoadjuvant therapy.