变性高效液相色谱法分析中国人非小细胞肺癌、结直肠癌中表皮生长因子受体突变情况和临床意义

Detection of EGFR mutation by DHPLC analysis in Chinese NSCLC and colorectal carcinoma patients and its clinical implication

目的初步了解我国NSCLC和结直肠癌患者EGFR突变的发生率及与此相关的临床特征。方法利用含有野生型和突变型EGFR基因的质粒DNA,摸索条件,建立DHPLC最佳检测方法;收集北京协和医院近期NSCLC手术标本和结直肠癌的石蜡标本,通过PCR和DHPLC筛查突变,测序验证,并对结果进行统计学分析。结果在29例NSCLC标本中,8例发生突变,突变率为27·6%,其中6例为缺失突变、1例为点突变、1例为混合突变;8例女性中有7例发现突变,突变率为87·5%,而21例男性病人中只有1例发生突变,突变发生率为4·8%(P<0·001);8例无吸烟史的病人全部突变,突变发生率为100%,21例有吸烟史的病人无1例突变(P<0·001);20例腺癌病人中有8例突变,突变率为40·0%;9例鳞癌病人无一突变(P=0·026);肿瘤家族史和肿瘤分期则与突变无关。在37例结直肠癌标本中,未发现突变。结论中国人NSCLC的EGFR突变发生率明显高于欧美国家,且以19外显子上的缺失突变为主。突变发生与女性、无吸烟史和腺癌有相关性,与肿瘤家族史和肿瘤分期没有相关性。结直肠癌EGFR未发现突变。DHPLC可作为EGFR突变筛查方法。

Objective To investigate the incidence of EGFR mutations in Chinese NSCLC and colorectal carcinoma patients and related clinical features. Methods Decide the proper setup for DHPLC assay with plasmid DNA containing the wild - .type and mutant- type EGFR DNA. Collect 29 frozen NSCLC samples and 37 colorectal carcinoma samples in paraffin. Detect their EGFR mutations by PCR and DHPLC. Then confirm the mutations by sequencing. And analyse the results with SPSS. Results 29 NSCLC samples were checked with a total mutation rate of 27.6% （8/29）, in which 75.0% （6/8） is in- frame deletion at exon 19, 12.5% （1/8） is point mutation at exon 21 and 12.5% （1/8） is mixed mutation. Among them, seven mutations were found in eight females （87.5%） and one in 21 males （4.8%）. All the eight mutations were found in 20 adenoearcinomas （40.0%）. And all the mutations were found in eight never- smoking patients （100%）. No relations were found between the mutation rate and family history and cancer staging. No mutation was found in 37 colorectal samples. Conclusion The EGFR mutation rate in Chinese NSCLC patients is distinctly higher than in European and Americans. Most of these mutations were in - frame deletions at exon 19. High mutation rate correlates with females, adenocarcinoma and never- smoking. There is no EGFR mutation detected in colorectal patients.