Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
Cancer. 2014 Oct 1;120(19):3040-8. doi: 10.1002/cncr.28792. Epub 2014 Jun 24.
Hispanics are the largest nonwhite ethnic group in the US population, and they have higher incidence and mortality rates for gastric cancer (GC) than whites and Asians. Studies have identified several genetic susceptibility loci and intermediate phenotypic biomarkers for GC in whites and Asians. No studies have evaluated genetic susceptibility and intermediate phenotypic biomarkers in Hispanics.
In a case-control study of 132 Hispanic patients with GC (cases) and a control group of 125 Hispanics (controls), the authors evaluated the association of 5 single nucleotide polymorphisms (SNPs) that predispose whites and/or Asians to GC and of 2 intermediate phenotypic markers in peripheral blood leukocytes, ie, telomere length and mitochondrial DNA (mtDNA) copy number, with the GC risk.
The variant C allele of the reference SNP rs2294008 in the PSCA gene was associated with a significantly reduced risk of GC (per allele-adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.33-0.77; P = .002). Leukocyte mtDNA copy numbers were significantly lower in GC cases (mean ± standard deviation, 0.91 ± 0.28) than in controls (1.29 ± 0.42; P < .001). When individuals were dichotomized into high and low mtDNA copy number groups based on the median mtDNA copy number value in the controls, those who had a low mtDNA copy number had a significantly increased risk of GC (aOR, 11.00; 95% CI, 4.79-25.23; P < .001) compared with those who had a high mtDNA copy number. Telomere length was not associated significantly with the risk of GC (aOR, 1.21; 95% CI, 0.65-2.27; P = .551).
Hispanics share certain genetic susceptibility loci and intermediate phenotypic GC biomarkers with whites and Asians and may also have distinct genetic susceptibility factors.
西班牙裔是美国人口中最大的非白人群体，他们患胃癌（GC）的发病率和死亡率高于白人和亚洲人。研究已经确定了几个与白人和亚洲人 GC 相关的遗传易感性和中间表型生物标志物。尚未研究西班牙裔人群中的遗传易感性和中间表型生物标志物。
在一项对 132 名西班牙裔 GC 患者（病例）和 125 名西班牙裔对照组（对照）的病例对照研究中，作者评估了 5 个易导致白人/亚洲人 GC 的单核苷酸多态性（SNP）和外周血白细胞中的 2 个中间表型标志物（端粒长度和线粒体 DNA（mtDNA）拷贝数）与 GC 风险的关联。
PSCA 基因参考 SNP rs2294008 的变异 C 等位基因与 GC 风险显著降低相关（等位基因调整后的比值比[aOR]，0.51；95%置信区间[CI]，0.33-0.77；P = 0.002）。GC 病例的白细胞 mtDNA 拷贝数明显低于对照组（平均值±标准差，0.91±0.28）（1.29±0.42；P<0.001）。当根据对照组 mtDNA 拷贝数中位数将个体分为高和低 mtDNA 拷贝数组时，与高 mtDNA 拷贝数组相比，低 mtDNA 拷贝数组的 GC 风险显著增加（aOR，11.00；95%CI，4.79-25.23；P<0.001）。端粒长度与 GC 风险无显著相关性（aOR，1.21；95%CI，0.65-2.27；P = 0.551）。
西班牙裔人与白人和亚洲人共享某些遗传易感性和中间表型 GC 生物标志物，也可能具有独特的遗传易感性因素。
