Research on esophageal cancer in China: a review.

Research on esophageal cancer in the People's Republic of China is reviewed. Massive epidemiological studies revealed the prevalence of this disease in China, especially in the Taihang Mountain range areas in the north. Gullet cancer in chickens was also observed in the high-incidence area of Linxian in Henan, suggesting the presence of cancer-causing substances in the environment. Research on the etiology of this cancer has been pursued extensively. Moldy food and pickled vegetables were shown to contain carcinogens. In chemical etiology, nitrosamines and their precursors have received the most attention. The possible roles of trace element deficiencies in the soil, nutritional deficiencies, fungal infection, polycyclic hydrocarbons, and other factors in contributing to the high cancer incidence have been studied. The esophageal cancer problem has also been investigated at the cellular and immunological levels. Mass cytological surveys allowed many cases of early cancer to be detected and treated. Precancerous changes and the use of interventive therapy have been studied in animal models and patients. Prevention, early detection, and early treatment of this cancer have been pursued vigorously in many areas of China.