结直肠癌原发灶与肝转移灶K-ras基因状态的研究

目的观察K-ras基因在结直肠癌原发灶及肝转移灶的突变状态。方法采用富集PCR配对测序法检测46例（男35例,女11例）结直肠癌肝转移患者原发灶及肝转移灶K-ras基因突变状态,其中结肠癌肝转移21例（45.7%）,直肠癌肝转移25例（54.3%）。结果46例中有18例（39.1%）原发灶K-ras基因为突变型,其中17例对应的肝转移灶K-ras基因为突变型,1例对应的肝转移灶K-ras基因为野生型。28例（60.9%）原发灶K-ras基因为野生型者中,26例对应的肝转移灶K-ras基因为野生型,2例对应的肝转移灶K-ras基因为突变型。统计分析表明,原发灶与肝转移灶K-ras基因突变状况差异无统计学意义（P=1.00）。结论转移性结直肠癌原发灶与肝转移灶的K-ras基因突变状态差异无统计学意义。

K-Ras Status in Primary Colorectal Cancers and Liver Metastatic Sites

Objective More and more studies have shown that K-ras mutations predict resistance to antiepidermal growth factor receptor therapy in metastatic colorectal cancer（mCRC） patients.Nevertheless,most researches were conducted on samples from primaries.Considering the heterogeneity of tumor cells,we aimed to evaluate the degree of concordance of K-ras status between primaries and liver metastatic sites.Methods Forty six cases（35 male,11 female） of metastatic colorectal cancer were collected.And the site of primary tumors was in colon in 21 patients（45.7%） and in rectum in 25 patients（54.3%）.We detected K-ras codon 12 and 13 mutations from primaries and related liver metastatic sites by enriched PCR coupled sequencing method.Results K-ras mutation was found in 18（39.1%） primary tumors in which the corresponding liver metastatic site was wild-type in only one patient.Mutation was found in two metastases cases out 28 cases of K-ras wild-type primary cancers.There is no statistic significant difference between the primary tumors and metastatic sites（P=1.00）.Conclusion Our results indicate that the detection of K-ras mutations in either primary or metastatic tumors from patients with mCRC was concordant,and this assessment could be used to predict response to EGFR-targeted therapies.