The use of epidemiology, scientific data, and regulatory authority to determine risk factors in cancers of some organs of the digestive system. 5. Stomach cancer.

In 1930, stomach cancer was the leading cause of death due to cancer among men in the United States. Among women it was the third leading cause of cancer deaths. Although it is well known that death rates for stomach cancer have diminished dramatically over the past 50 years, stomach cancer still has the third poorest 5-year relative survival rate of the different cancers, after pancreatic and lung cancer. Most evidence indicates that environmental factors play an important role in the development of stomach cancer. The remarkable decrease in stomach cancer mortality over the past 50 years and the results of a variety of migrant studies support this review. Several published case-control studies have shown positive associations with preserved meat and salted and pickled food in general. However, there are negative associations with vegetables, fruits and milk; vitamin C is implicated. Milk has both positive and negative associations. This points to the possibility of a carcinogen produced by traditional preservation methods such as salting and suggests that fresh vegetables and fruits and high intakes of vitamin C may reduce the risk. What specific role/s the diet plays in the incidence of stomach cancer remains to be seen. There is a need to elaborate the relationship of such factors as age, sex, migration, geography, environmental factors, and diet to the carcinogenic process that produces cancer of the stomach.