Abstract
Subrenal capsule (SRC) assay was initially developed by Bogden et al. and has been reported to be an effective chemosensitivity test for individual tumor patients. However, there still remain some inherent problem such as the influence of the host immune responses.
Meanwhile, peplomycin (PEP) is an analogue of bleomycin (BLM) with a broader antitumor spectrum and less pulmonary toxicity, and is often applied to the treatment of oral squamous cell carcinomas (SCC), especially highly differentiated SCCs.
However, we have experienced some cases in which PEP is ineffective in the case of highly differentiated SCCs.
Therefore, experimental studies were conducted to examine the possibility of an SRC assay of PEP modified by Kawahara et al.
Mice were pretreated with a minute immunosuppressive dose of X-ray irradiation. When PEP was administered on the Days 1, 3, 5, at the total dose of 60.0mg/kg, the antitumor effect was more pronounced than in the case of any other regimen.
Seventy-two cases were examined and it was possible to evaluate every case of 56 cases. Subjected to tumor differentiation and SRC assays, there was no significant correlationship between highly differentiated SCCs and other types of tumor differentiation. Sixteen correlations were established between the the results of the SRC assays and clinical responses, and 14 cases (87.5%) showed a good correlationship.
As results of the foregoing studies, the modified SRC assay was acceptable as an experimental model for predicting the sensitivity of PEP to highly differentiated SCCs. Since PEP is not always effective in the case of highly differentiated SCCs, it is necessary to apply the modified SRC assay before applying chemotherapy.
