Comparative characteristics of models of advanced ovarian carcinoma after orthotopic and intraperitoneal transplantation of a syngeneic tumor

Aim. To reveal the characteristic features of tumor growth after orthotopic (OT) and intraperitoneal transplantation (IT) of high-grade syngeneic ovarian carcinoma. Material and methods. Twenty mature female Wistar rats were randomized into two groups of ten each. The first group – animals underwent OT of ovarian carcinoma (4,3×106 cells) under the membrane of the bursa of the left and right ovaries; the second group – animals underwent IT of the tumor (4,3×107 cells). The endpoints of the study included an assessment of the overall survival (OS) of rats in two groups, determination of the peritoneal cancer index (PCI) on autopsy, and ascites weight. Autopsy material was histologically assessed analysis by light microscopy after standard staining. Cytological examination of ascitic fluid was carried out. Results. Median OS was 29 days and 21 days in the OT and IT groups, respectively (log-rank test, P = 0.0276). Autopsy did not reveal significant differences in total PCI (12.6 vs 13.6 in the OT and IT groups, respectively) and ascites weight (78.0 g in the OT vs 65.8 g in the IT group). The method of transplantation did not affect the tumor grafting, histological characteristics, the nature of intraperitoneal spread and the ascites volume. It should be noted that there was a greater volume of tumor lesions in the organs of the reproductive system of rats (ovaries, uterus with horns, paragonadal fat pad) in the OT group. Conclusion. Both methods of transplantation allow to reproduce the advanced stages (III-IV stages) of epithelial ovarian carcinoma in women. OT requires more time and operating conditions. OT and IT can be used to solve various problems in fundamental and routine preclinical cancer research.