The effect of chemotherapeutic agents on human oral squamous cell carcinoma transplanted to nude mice: a histologic study.

Clearly differentiated squamous cell carcinomas were transplanted to the backs of nude mice; tumor cells of a human tongue carcinoma cell line were used. Animals bearing tumors that measured at least 4 mm in diameter were treated with either methotrexate (MTX), cis-diamminedichloroplatinum II (CDDP) or bleomycin intraperitoneally for 5 days. Histologic evaluation of tumors obtained 24 hours after the last injection revealed degenerative and necrotic morphology in all treatment groups. The histologic alterations were observed prior to any clinical evidence of tumor shrinkage. The most impressive changes were found in CDDP-treated tumors, with creation of large pseudocysts containing necrotic material and cell debris. Pseudocyst formation was less obvious in MTX-treated animals and was absent in bleomycin-treated tumors. Drug treatment had no obvious influence on the keratinization in tumors. The findings suggest that the nude mouse model may be useful for the histologic determination of drug-induced effects on tumors in human beings.