Experimental Tumor Induction in a Circumscribed Region of the Hamster Trachea: Correlation of Histology and Exfoliative Cytology2

Abstract

A method for the induction of carcinomas in a circumscribed region of the hamster trachea is reported. By means of a special catheter, a solution of N-nitroso-N-methylurea was applied twice a week to about a 6-mm length of the trachea 10- to 16-mm distal from teh vocal cords. Slight alteration of this catheter allowed sampling of cytologic specimens directly from the surface of the carcinogen0exposed epithelium. This procedure permitted the simple and accurate correlation of sequential histologic and cytologic changes observed during tumor development in the hamsters. Noninvasive dysplastic and metaplastic lesions were seen in animals killed after 5 and 10 weeks of carcinogen application. These epithelial changes could be readily correlated with abnormal exfoliated cells abundantly present in cytologic specimens from these animals. Exposure to carcinogen for 15 weeks induced a 100% tumor incidence exclusively at the application site. More than 75% of the malignancies appeared within 15-20 weeks after the start of carcinogen administration. Most tumors were epidermoid carcinomas but some anaplastic large-cell carcinomas were also observed. Cytologic specimens of tumor-bearing animals had many cells conclusive of malignancy. The new experimental system lends itself to study of the effect of topically applied anticarcinogenic or cocarcinogenic agents on different carcinogen-induced epithelial lesions whose regression or progression can be followed by exfoliative cytology.

A Practical Model of Bronchogenic Carcinoma in Camm-Harley Guinea Pigs and Golden Syrian Hamsters

“…In order to gain access to the preneoplastic lesions, Schreiber (et al, 1975) devised a method to induce carcinomas in a circumscribed region of the hamster trachea. He did this by using a special catheter to apply N-nitroso-N-methylurea to the trachea, twice weekly.…”

A Method of Producing Carcinoma in Upper Aerodigestive Tree and Esophagus of the Syrian Golden Hamster Using Wounding and Instillation of N-Methylnitrosourea

“…Carcinoma of the larynx (9,510), pharynx (8,950), and esophagus (7,250) affected f25,700 patients in the United States in 2005 (1). Cancers with an epicenter within the laryngeal framework itself comprised f10,000 of these aerodigestive malignancies (1).…”

A step section method for full histopathological assessment of carcinogen‐affected target tissue during respiratory carcinogenesis

“…In three other varieties of small animal NSCLC models that have been frequently utilized, the carcinogenaffected sites in the respiratory epithelium are predetermined. One model employs repetitive perfusion of a short distal tracheal segment with carcinogen-containing solution (Schreiber et al, 1975). Although complete histopathological examination of the perfused tracheal segment is feasible, the method requires 1) multiple manipulations of the animal and 2) a complex, costly perfusion apparatus for limiting the extent of tracheal mucosal exposure to carcinogen.…”