到目前為止在胃癌方面人體的感受性基因仍尚未被証實，因此本研究以八十三對胃癌病例與性別、年齡配對的健康受試者為對象，探討具有基因多形性的前致癌基因L-myc；參與代謝與引發胃癌有關的異種物質代謝第一期與第二期反應的CYPIA1、CYPIIE1、GSTT1和GSTM1基因，以及參與DNA修復的AGT基因，其不同基因型與胃癌發生的相關性。本研究發現，抽菸對胃癌的發生可使相對危險性提升3.3倍(95%CI=1.3～8.4, P=0.01)。L-myc L對偶基因的危險性，在胃癌的致癌過程中並不是一個主要的危險因子。CYPIA1 Ile-Val基因型與GSTM1非無效基因型都是具有保護作用的基因型， 分別可使相對危險性降至0.5(95% CI分別為0.3～1.1, 0.2～1.1；P分別為0.08及0.10)。CYPIIE1 c2對偶基因則具有顯著的危險性，且相對危險性會隨著c2對偶基因的增加而增加。GSTT1非無效基因型亦是屬於具有危險性的基因型，可增加1.9倍的風險(95%CI=0.9～3.9, P=0.07)。

　　　　　The aims of this case-control study involving 83 pairs of gastric cancer patients and sex, and age-matched healthy controls are to elucidate the relationship between the genotypes of cancer susceptibility genes (such as L-myc, CYPIA1, CYPIIE1, GSTT1, GSTM1, and AGT) and the development of gastric cancer. The results and conclusions obtained are as follows. (1)In gastric cancer, the odds ratio of smoking was 3.3 (95% CI=1.3-8.4, P=0.01); indicating that smoking was a major risk factor for gastric cancer. (2)The odds ratio of L-myc L allele was close to one, suggesting little association with gastric cancer. (3)The odds ratios for CYPIA1 Ile-Val and GSTM1 non-null genotype were 0.5(95% CI=0.3-1.1 and 0.2-1.1; P=0.08 and 0.10, respectively); therefore, they seemed to show protective effects. (4)The odds ratio of CYPIIE1 c2/c2 genotype was found to be 6.5 (95% CI=1.1-38.1, P=0.04); thus, CYPIIE1 c2 allele was a susceptible allele for gastric cancer. (5)GSTT1 non-null genotype was also a susceptible genotyp e for gastric cancer, because its odds ratio was 1.9 (95% CI=0.9-3.9, P=0.07).