Abstract

To study the effect of the environments shared by spouses on the development of cancer and some chronic diseases, we analyzed the correspondence of disease history in 21,592 fathers and mothers using the baseline data of a population-based cohort study. The observed number of cases (O) whose parents had the same disease history was statistically significantly greater than the expected (E); the O/E ratio was 1.53 (95% confidence interval (CI): 1.43-1.63) for all malignant neoplasms, 5.22 (95% CI: 2.81-9.70) for esophageal cancer, 1.63 (95% CI: 1.37-1.93) for stomach cancer, 3.01 (95% CI: 1.89-4.79) for colorectal cancer, 3.90 (95% CI: 2.75-5.53) for liver cancer, 3.14 (95% CI: 1.95-5.08) for lung cancer, 6.73 (95% CI: 2.53-17.87) for bladder cancer, 1.66 (95% CI: 1.54-1.78) for apoplexy and 1.67 (95% CI: 1.51-1.86) for heart disease. The results of the present study suggest that the environmental factors shared by family members for a long time may contribute to familial aggregation of cancer and some chronic diseases.