Etiologic and epidemiologic factors of carcinoma of the esophagus.

Carcinoma of the esophagus is one of the most interesting tumors due to the great diversity with regard to its regional incidence worldwide. The areas of especially high incidence include the Caspian provinces of Iran and certain regions of the People's Republic of China, South America and Africa. The precise cause of these major regional differences with regard to the incidence of carcinoma of the esophagus are still not fully clarified. The results of the present study explain conceptions with regard to the etiopathogenesis and shows that the factors with a promotive role in various individual regions differ, in some instances, considerably from one another.