Statistics of Esophageal Cancer Progression in Man

Abstract

Cancer of the esophagus, generally, is seldom diagnosed prior to the manifestation of symptoms indicating that the disease has progressed to an advanced stage. For this reason, the processes of growth and spread are difficult to characterize clinically. A number of studies from around the world (2, 6–8, 11) have focused on the variable epidemiology of this disease and the incidence of “precancerous” lesions, some of which are related to identified carcinogenic exposures. Screening programs in China, which are discussed in another section of this monograph, and Japan have effectively used exfoliative cytology for early detection in populations where carcinoma of the esophagus is one of the most common malignancies. From these reports cancer of the esophagus is described as beginning “when malignant change takes place in the basal layers and gradually extends upward displacing the dysplastic cells in the superficial portion of the epithelium. A carcinoma in situ is thus formed. The early infiltrative carcinoma develops from carcinoma in situ of a large area and the microfoci of infiltration, as a rule, develop first from the central zone of the carcinoma in situ. ”