目的：测定中国汉族与蒙古族结肠癌患者KRAS, NRAS, PI3KCA, BRAF基因突变频率及分布情况，进而评估基因突变与临床病理特征的关联。 方法：在内蒙古自治区人民医院收集需手术治疗的汉族及蒙古族结肠癌患者。术中切取肿瘤组织，石蜡包埋，DNA提取。基因突变检测试剂盒测定KRAS, NRAS, PI3KCA, BRAF基因突变情况。 结果：汉族右半结肠癌KRAS及PI3KCA基因突变频率显著高于左半结肠癌（P<0.05）。T3+T4组蒙古族结肠癌患者KRAS基因突变显著高于T1+T2组（P= 0.029）。此外，汉族右半结肠KRAS基因突变频率明显高于蒙古族突变频率（P= 0.025）。 结论：汉族与蒙古族结肠癌患者KRAS, NRAS, PI3KCA, BRAF基因突变频率相似，然而，汉族右半结肠KRAS基因突变率明显高于蒙古族突变率。后续的研究应着重于评估这种差别对右半结肠癌靶向治疗有效率及预后情况的影响。 关键词：结肠癌, 基因突变，汉族，蒙古族

Objective: The aim of this study was to assess mutation frequencies and distributions in the Chinese Han and Mongolian CRC patients and determine their correlations with certain clinicopathological features. Methods: Han and age- and sex-matched Mongolian CRC patients from Hohhot were identified and retrospectively reviewed. All the tumor tissue was cut in operation, then tissue was embedded in paraffin. After that, DNA extraction was preformed. The genetic testing kit (Fluorometric real-time PCR) was used to detect the condition of KRAS, NRAS, PI3KCA, BRAF mutations. Results: Associations between KRAS mutations and locations of primary tumor were found statistically significant (P= 0.004). And significant correlation was also observed between PI3KCA mutations and locations of primary tumor (P= 0.032). In Chinese Mongolian CRC patients, significant association was only found between KRAS mutations and invasion depth (P= 0.029). Besides, we found prevalence rates of KRAS in Chinese Han right-sided CRC was higher than in Mongolian (P= 0.025). Conclusion: The frequency of KRAS, NRAS, PI3KCA, BRAF mutations in Chinese Han CRC patients were similar to corresponding frequency in Mongolian expect the prevalence rates of KRAS in Chinese Han right-sided CRC was higher than in Mongolian. Further studies are warranted to examine their impact on prognosis and response to targeted treatment.