结直肠癌KRAS基因突变与临床病理特征的关系

Correlation between KRAS mutations and clinicopathologic features in colorectal carcinomas

目的探讨结直肠癌患者KRAS基因突变与临床病理特征之间的关系。方法应用显微切割技术及蝎形探针扩增阻滞突变系统（Scorpions ARMS）检测167例经手术或活检证实的结直肠癌患者石蜡包埋的肿瘤组织中KRAS基因第12、13位密码子突变，应用统计学方法分析KRAS基因突变与临床病理特征的相关性。结果167例结直肠癌患者中男性109例，女性58例。66例患者存在KRAS基因突变，突变检出率为39．5％（66／167）。第13位密码子检出1种突变类型，21例为G13D点突变，突变检出率为12．6％（21／167）。第12位密码子检出6种突变类型，15例为G12D点突变，突变检出率为9．0％（15／167）；13例为G12V点突变，突变检出率为7．8％（13／167）；6例为G12C点突变，突变检出率为3．6％（6／167）；5例为G12A点突变，突变检出率为3．0％（5／167）；4例为G12S点突变，突变检出率为2．4％（4／167）；还有2例为G12R点突变，突变检出率为1．2％（2／167）。余101例结直肠癌患者均为KRAS基因野生型。女性患者KRAS基因突变率（50．0％，29／58）高于男性（33．9％，37／109），两者差异具有统计学意义（P〈0．05）。18例为转移性结直肠癌患者，其KRAS基因突变检出比例为7／18，与149例原发性结直肠癌患者的突变检出率差异无统计学意义（P〉0．05）。结论结直肠癌女性患者的KRAS基因突变检出率高于男性患者，而与年龄、肿瘤部位、分化程度、组织学类型无相关性。原发性与转移性结直肠癌患者KRAS基因突变检出率元明显著异。

Objective To investigate mutations of KRAS characteristics of colorectal carcinomas （CRC） in Chinese. Methods gene and clinicopathological Tumor ceils were collected by microdissection from paraffin-embedded tumor specimens and adjacent normal colon tissues from 167 CRC patients. Genomic DNA was extracted and mutations of KRAS gene （ codons 12 and 13 ） were detected by scorpions amplification refractory mutation system （Scorpions ARMS ）. Results KRAS mutations were identified in 66 patients （39. 5% ） , including G13D （21 cases, 12. 6% ） , G12D （ 15 cases, 9. 0% ）, G12V （13 cases, 7.8%）, G12C （6 cases, 3.6%）, G12A （5 cases, 3.0%）, G12S （4 cases, 2.4%） and G12R （2 cases, 1.2% ）. Female patients had a higher KRAS mutation rate than male （50. 0% , 29/58 vs. 33.9%, 37/109, P 〈0. 05）. However, KRAS mutations did not correlate with the patient age, tumor sites, histological types and grades （ P 〉 0. 05 ）. Additionally, 7 of 18 patients with metastatic CRC had KRAS gene mutations. Overall, KRAS gene mutation was identified in 59 patients among 149 primary CRC （39. 6% ）. There was no significant difference in KRAS mutation between primary and metastatic tumors （P 〉 0. 05 ）. Conclusions The detection rate of KRAS mutation is higher in female CRC patients than the males. The presence of KRAS mutation does not significantly correlate with the patients＇ age, tumor site, differentiation grades and histological types. There was no significant difference in KRAS mutation between the primary and metastatic tumors.