RESUMEN
Objective Studies on cardia-cancer caused by hereditary factors. Methods Case-control method was adopted,with information including name,sex,date of birth,date of death of all the Ⅰ,Ⅱ,Ⅲ relatives of the patients,diagnosis and the treatment collected. The hereditary probability of cardia cancer and the separation degree were calculated by Falconer and Li-Mentel-Gart. Results (1) Prevalence rates of cardia-cancer on relative Ⅰ,relative Ⅱ,relative Ⅲ of cardia-cancer patients appeared to be 0.54%,0.04%,and 0.05% respectively. Prevalence rates of upper-digestive-tract-cancer of relative Ⅰ,relative Ⅱ,relative Ⅲ of cardia-cancer patients showed as: 2.50%,0.36% and 0.13% respectively. Data showed that relative Ⅰ> relative Ⅱ> relative Ⅲ and family cluster existed in both males and females. (2) Cardia-cancer hereditary probability of the relative Ⅰ cardia-cancer probands was 11.71%,with males as 14.01% and females as 14.72%. The upper-digestive-tract-cancer hereditary probability of the relative Ⅰ cardia-cancer probands was 13.87%,with males as 11.49% and females as 23.08%,both below 25%,indicating this was a low hereditary cancer. (3) The upper-digestive-tract-cancer separation of the blood compatriots of cardia-cancer patients was 0.0452,with males as 0.0441 and females as 0.0507,both below 0.25,indicating the nature of a multi-gene but not single-gene hereditary way. Conclusion Hereditary factor is recognized as one of the high risk cardia cancer,but not the most risky factor causing the high morbidity of cardia cancer in Shanxi province.