中国人食管癌及肺癌发病风险与p53基因多态性

目的　比较中国北方人对食管癌及肺癌的易感性与p5 3基因第 72密码子多态性的关系。方法　应用序列特异性引物 ,以PCR方法检测 173例食管鳞状上皮癌、98例非小细胞肺癌患者及 136例健康对照者的p5 3基因第 72密码子的基因型。结果　食管癌与肺癌组p5 3等位基因及基因型分布无明显差异。食管癌和肺癌组的Pro等位基因频率明显高于对照组 (P值分别为 0 .0 2 4及0 .0 2 7)。Pro/Arg及Arg/Arg基因型频率在两肿瘤组及对照组差异无显著性 (P >0 .0 5 ) ,而食管癌和肺癌组的Pro/Pro基因型频率明显高于对照组 (P值分别为 0 .0 4 1及 0 .0 2 6 )。Pro纯合子患食管癌与肺癌的风险较Arg纯合子高 2倍左右 校正比值比分别为 2 .12 (95 %CI=1.13～ 4 .0 1)和 2 .30 (95 %CI =1.13～ 4 .93) ],且与吸烟无协同作用。结论　Pro/Pro基因型为中国北方人患食管癌及肺癌的独立易感因素 ,两种肿瘤的发病可能有共同的遗传基础。

p53 gene polymorphism with susceptibility to esophageal cancer and lung cancer in Chinese population

OBJECTIVE: To investigate the association of p53 codon 72 polymorphism with susceptibility to esophageal cancer and lung cancer in the northern Chinese population. METHODS: p53 codon 72 genotyping was performed by amplifying DNA fragments with sequence specific primers among 173 patients with esophageal squamous cell carcinoma, 98 with non-small cell lung carcinoma as well as 136 healthy controls. RESULTS: No significant difference of p53 allelotype and genotype distribution was observed between esophageal cancer and lung cancer patients. The Pro allele frequency was significantly higher among esophageal cancer and lung cancer patients than among healthy controls (P value was 0.024 and 0.027 respectively). There were no significant differences in Pro/Arg and Arg/Arg genotype frequency among cancer patients and healthy controls (P > 0.05). However, the Pro/Pro genotype frequency was significantly higher among esophageal cancer and lung cancer patients than among healthy controls (P value was 0.041 and 0.026 respectively). The risk of Pro homozygotes for both esophageal cancer and lung cancer was about 2 times against Arg homozygotes with adjusted odds ratio of 2.12 (95% CI = 1.13 - 4.01) and 2.30 (95% CI = 1.13 - 4.93), respectively. There was no interaction between p53 Pro/Pro genotype and smoking status to the risk for esophageal cancer and lung cancer. CONCLUSION: In the northern Chinese population, p53 Pro/Pro genotype is an independent risk factor for both esophageal cancer and lung cancer. The possible common genetic basis of the development of these two cancers is suggested by this study.