Differential susceptibility to bronchial carcinogenesis in syngeneic hamsters

Previous studies of chemical carcinogenesis in the lung of Syrian golden hamsters have utilized outbred (nonsyngeneic) animals. Using the endobronchial sustained release implant technique, which causes focally originating cancers in outbred hamsters, we studied the course of bronchial carcinogenesis in two varieties of syngeneic Syrian golden hamsters, the LSH and the F1D strains (BIO 15.16 male X BIO 87.20 female). With either 10% benzo(a)pyrene or 10% methylcholanthrene sustained release implants the time course of epithelial transition from normal to neoplastic was the same for F1D hamsters as previously described for outbred hamsters. Using 10% benzo(a)pyrene sustained release implants the incidence of cancers as a function of time was significantly lower (P less than 0.001) in LSH hamsters as compared to outbred and F1D animals. Of 19 tumors transplanted into syngeneic F1D hamsters, 16 have been successfully propagated by serial transplantation. We conclude that (a) F1D hamsters are comparable to outbred animals in the response of their bronchial epithelium to endobronchial benzo(a)pyrene and methylcholanthrene, (b) there are significant differences in susceptibility to bronchial chemical carcinogenesis among hamster strains, thereby giving opportunity to study potential genetic control mechanisms during bronchial carcinogenesis, and (c) F1D hamsters are suitable for studies of lung cancer biology using tumor transplantation methods.