Intrabronchial Implantation: A Method for the Orthotopic Propagation of Human Lung Tumors in Athymic Nude Mice

5S ond study consisted of 70 golden syrian hamsters: 54 experimental and 16 control animals. The implantation of the thread in the trachea induced a regenerative basal cell hyperplasia of the epithelium. We Ibund squamous metaplasia and progressive intraepithelial neoplasia (lEN) prior to the development of squamous cell carcinoma (CA). In the experimental guinea pigs, only one invasive CA was found at 265 days postoperation. In the experimental hamsters, the first CA was seen at 55 days postoperation, and 65% of the animals sacrificed between 120 and 250 days developed CA. Most of the hamsters with CA also developed spindle cell tumors in the tracheal stroma. The control hamsters and guinea pigs did not develop lEN, and the mature respiratory epithelium was reconstituted. We conclude that this method reliably produces localized, readily accessible preneoplastic and neoplastic lesions in the trachea of hamsters and, to a lesser extent, in that of guinea pigs. This model of squamous cell bronchogenic carcinoma should prove useful in the study of tumor ultrastructure, the immunologic response to cancer, and the relationship of diet to cancer.