Study On The Population Genetic Characteristics Of Esophageal Cancer

Esophageal cancer is the fourth cause of cancer death in China and the 70% esophageal cancer cases are found in China in the whole world. Previous studies on genetic epidemiology showed that the genetic susceptibility to EC was one of the important causes for the high prevalence and familial gathering of this malignancy in some areas of China. So it is of great significance to reveal the mechanisms of the genetic susceptibility and establish effective ways of screening susceptible individuals for mass prevention of EC in high-incidence areas. One of the major goals of the genetic studies on EC is to identify the susceptibility genes in population.Xin-an and Xin-Xiang county, which are lie in the southwest of Henan, have a population of 480 thousands .More than 40% of cancer death was due to EC. A genetic epidemiology surrey had been done, 79 EC families had been studied. EC cases from 2003,8—2005,8 has been collected. Data from their spouses, parents, grand parents, uncles ants and their children have also been collected, including clinic and pathologic diagnosis, ages of birth, onset of EC, death, household living time harmful habits, etc.(1) The distribution of EC in families did not fit well the binomial distribution, despite familial aggregation. (2) The results showed that the heritability of EC among first grade blood relatives was 67.02%±7.31%, that among second grade blood relatives was 43.08%±9.80%, the summing up powered heritability was 53.16%±6.74%. (3) the segregation ratio was 0.042, far less than 0.25, suggesting a mufti-gene effect. (4) Complex segregate ion analysis was performed by using statistical analysis for genetic epidemiology SEGREG (SAGE- SEGREG). The genetic model and gene frequency were estimated. 79 pedigrees with EC were collected. The complex segregation analysis found the genetic model of EC to be additive. The possibility of some different models may co-exist under different circumstances. This study suggests that the genetic mode of EC could be the major gene trait, and additive mode is the best fitted one.