Differential Cumulative Risk of Genetic Polymorphisms in Familial and Nonfamilial Esophageal Squamous Cell Carcinoma.

Abstract

To explore the relationship between family history of esophageal cancer, SNPs, and the risk of esophageal squamous cell carcinoma (ESCC), we performed a population-based case-control study and developed a genetic family history-related risk (GFR) score and non-family history-related risk (GnFR) score to quantify the cumulative number of risk genotypes carried by each individual. We used data of 700 patients with nonfamilial ESCC, 341 patients with familial ESCC, 1,445 controls without a family history of esophageal cancer, and 319 controls with a family history. We genotyped 87 genetic variants associated with the risk for ESCC, and constructed GFR and GnFR scores for cases and controls. Our results show that ESCC risk increased with higher GFR score (P trend = 0.0096). Among the familial subgroup, we observed a nearly 7-fold [95% confidence interval (CI), 1.92-24.77] higher risk of ESCC in the highest GFR score group. The corresponding estimate was only 2-fold (95% CI, 1.41-3.93) higher risk of ESCC, in the stratum without a reported family history of esophageal cancer. Certain cell signaling pathways and immune-related pathways were enriched, specifically in familial ESCC. Results from a reconstructed cohort analysis demonstrated that cumulative risk to get esophageal cancer by age 75 years was 13.3%, 10.2%, 8.2%, and 5.1%, respectively, in four subgroups as defined by first-degree relatives of cases or controls with high or low genetic risk score. In particular, the cohort of relatives of ESCC cases with low genetic risk score exhibit a higher cumulative risk than the cohort of relatives of controls with high genetic risk score. It demonstrates that environmental factors play a major role in esophageal cancer. Further studies are warranted to dissect the mechanisms of shared environmental and genetic susceptibility affecting the risk of getting ESCC. Our study highlights that the need of preventive strategies to screen certain genetic polymorphisms, especially in individuals whose relatives had ESCC.