中文摘要：

目的：观察结直肠癌组织中k-ras基因突变情况，探讨k-ras基因突变与结直肠癌生物学行为的关系。方法：采用实时荧光定量PCR法检测123例结直肠癌组织中k-ras邯基因1号外显子12、13密码子突变情况，结合其临床病理资料分析。结果：123例结直肠癌组织中k-ras基因突变者53例（40．8％），其中12密码子突变42例（34．1％），13密码子突变者11例（8．9％）。基因突变率与肿瘤大小、肿瘤侵润深度、分化程度无明显相关性，与淋巴结转移、肝脏转移及TNM分期有相关性（P〈0．05）。淋巴结转移多者k-ras基因突变率高，有肝脏转移者基因突变率高，TNM分期越晚基因突变率越高。结论：K-ras基因突变可能在结直肠癌的发生、发展中起重要作用，而且与淋巴结转移和肝脏转移有密切相关，可作为判断结直肠癌恶性程度的一个分子生物学指标。

英文摘要：

AIM ： To investigate mutations of oncogene k - ras in colorectal cancer tissues and the relationship between mutations of k - ras and biological behavior of colorectal carcinoma. METHODS ： The specimens of 123 patients with colorectal cancer were collected. Real - time fluorescence quantitative PCR were performed to detect k - ras mutations at codon 12 and codon 13 of exon 1, and the results were analyzed with the corresponding clinical pathological data. RESULTS： Among 123 colorectal cancer cases, point mutations were detected in 53 cases （40. 8% ）, point mutations at codon 12 were found in 42 （34. 1% ） cases, and 11 （8.9%） cases at codon 13. No closely relationship between mutations of k - ras and tumor size, location, invasive depth and differentiation extent was observed. The rate of k - ras mutation in the cases with more invaded lymph nodes was higher than that in the cases without invaded lymph nodes （ P 〈 0. 05 ）, and the rate of k - ras gene mutation in the cases with hepatic metastases was higher than that in no hepatic metastases （ P 〈 0. 05 ）. The rate of k - ras gene mutation was higher in TNM staging HI/1V than that in I/H（ P 〈 0. 05 ）. CONCLUSION ： Mutation of oncogene k - ras plays an important role in the carcinogenesis and development of colorectal cancer, and it is closely associated with invaded lymph notes and hepatic metastases, suggesting that mutation of k - ras indicates a poor prognosis.