Tumor Induction in Tracheal Grafts: A New Experimental Model for Respiratory Carcinogenesis Studies

Abstract

We described long-term survival of subcutaneous tracheal transplants in rats, mice, and hamsters. Instillation of carcinogenic polycyclic hydrocarbons into established rat tracheal grafts resulted in the development of hyperplasia, dysplasia, and squamous metaplasia within 4–7 days. Similar epithelial changes were also induced with cigarette smoke condensate. In one study, which is still in progress, invasive squamous cell carcinomas developed in 7 of 13 tracheal grafts between 26 and 35 weeks after instillation of 5 mg of either 3-methyl-cholanthrene or benzo[a]pyrene. No tumors have as yet appeared in grafts receiving 1 mg of N-nitroso-methylurea. We discussed the usefulness of this experimental model for morphogenesis and cocarcinogenesis studies.