A method for the experimental induction of bronchogenic carcinoma.

A methodology for the experimental induction of bronchogenie carcinoma in conditions related to those of human expo sure to respiratory carcinogens is described. Animal of choice is the hamster. Polynuclear hydrocarbon carcinogens are pre pared as suspensions of fine crystalline particles and attached to a finely particulated inert dust which acts as a carrier; the mixed dust is suspended in saline and administered by intratracheal instillation. Penetration and distribution patterns are described. No necrosis and no chronic inflammatory reactions other than phagocytosis are induced. Repeated intratracheal in stillations of benzo[a]pyrene with hematite dust induce up to 100% incidences of respiratory tract tumors, mostly bronchogenie carcinomas. The morphology of these tumors appears very close to that of human lung cancer; squamous cell car cinomas are the most frequent type followed by anaplastia car cinomas and by a few adenocarcinomas. The experimental model presented here appears adequate for studies on factors involved in the pathogenesis of cancer of the lung.