４‐ｎｉｔｒｏｑｕｉｎｏｌｉｎｅ １‐ｏｘｉｄｅ（４ＮＱＯ）誘発ラット舌癌に対するｐｅｐｌｏｍｙｃｉｎの抗腫よう効果に関する実験的研究

Abstract

We examined the antitumor effect of peplomycin morphologically using a rat model of tongue carcinoma induced by the carcinogenic agent, 4-nitroquinoline 1-oxide. We also studied the survival status of reproliferative tumor cells and the reproliferative movement of the tumor after the completion of peplomycin treatment.The effective rate of peplomycin was 25.5% if tumors showing a reduction of 1/2 or greater are designated as a positive response or 5.9% if histological evidence of Grade III or above is regarded as a positive response.We noted a correlation between clinical macroscopic type and the mode of invasion. The frequency of ingrowing growth patterns such as ulcer type was statistically hingher in types 4 C and 4 D, while outgrowing growth patterns were more commonly noted in types 1 to 3.We also noted that the higher the tumor invasion, the lesser was the antitumor effect both macroscopically and histologically. Therefore, when carrying out neo-adjuvant chemotherapy with peplomycin, the mode of tumor invasion can be an important factor in forecasting the effect of treatment.Even after the macroscopic eradication of the lesion by peplomycin treatment, we sporadically noted some sections with histological evidence of surviving tumor cells. Although the antitumor effect of peplomycin remained up to 20 days after completing treatment, it was most remarkable 10 days after treatment histologically.Macroscopically, tumors of ulcer type showing A type 4 C or 4 D mode of invasion were characterized by rapid reproliferation of surviving tumor cells and strongly tended to be heteromorphic.It was concluded that peplomycin preoperative chemotherapy is most effective when treatment is planned so that surgery can be carried out within 10 days after completing chemotherapy.