Epidemiology of pancreatic cancer in Japan.

Pancreatic cancer has been on the sharp increase in Japan in recent years, the rate of increase being as high as for lung and liver cancers. A large scale cohort study on pancreatic cancer in Japan revealed close associations with cigarette smoking and daily meat consumption among the many life-style associated risk factors studied. The risk was observed to be highest when both habits were combined. Their effect was practically multiplicative. A five year accelerated aging was observed in daily cigarette smokers and, when daily meat consumption was combined with daily smoking, the accelerated aging had extended to approximately 10 years. This somewhat non-specific background was considered relevant when evaluating the reasons for such an elevated risk of developing pancreatic cancer from smoking and meat consumption when looked at together with more specific biological mechanisms. The sharp increase in the consumption of animal fats in Japan in recent years was considered the most probable reasons for the recent increase in mortality from pancreatic cancer, in addition to an increase in other identified risk factors such as cigarette consumption. Further, possible exposure to hitherto unidentified chemicals must also be considered, as suggested by the elevated risk of developing pancreatic cancer in certain occupations such as chemical production.