[Effects of thermal burns of the esophagus on carcinogenesis induced by ethyl ethers of N-nitrososarcosine in rats].

The study was concerned with the effect of electro-thermocoagulation burn of the rat gullet on carcinogenesis induced by esophagotropic carcinogen--ethyl ester of N-nitrososarcosine (50 mg/kg, five times a week, four months). Treatment was started on day 15 postburn, and at 8 months tumors of the esophagus occurred in 71.8% including tumors in the burn area (46.8%). Forestomach neoplasms were observed in 15.6%. Animals treated with the carcinogen alone showed a significant decrease in both overall frequency of esophageal tumors (42.4%) and that for the burn area (18.1%) while frequency of forestomach neoplasia remained nearly the same (21.2%). Most tumors were benign papillomas. It was concluded that burn--induced cicatricial changes in the esophageal mucosa predispose to development and growth of tumors of this site.