BIOLOGICAL PROPERTIES AND RADIATION RESPONSES OF THE HAMSTER UTERINE CERVICAL SQUAMOUS-CELL CARCINOMA

Results of initial studies of the growth characteristics, immunogenicity, histopathology, and radiation response of a uterine cervical squamous cell carcinoma of the Syrian hamster are presented. The cervical carcinoma is a relatively loosely knit, undifferentiated, highly cellular tumor without a recognizable architectural pattern but with a gradation in cellular density decreasing from the perimeter to the center of the tumor. The vascular network corresponds with the histologic features such that radially arranged capillaries join a dilated, tortuous network at the perimeter and with a sparse network in the center of the tumor. Tests of the immunogenicity of the cervical carcinoma by either suppressing the immune mechanism(s) or sensitizing the animal to the tumor, indicate that this tumor provides little or no stimulus to the host immunologic system. After radiation exposures ranging from 1000 to 7000 R, tumor volume in persisting tumors shows a pattern of retardation and/or regression followed by regrowth which correlates with exposure. Increasing tumor control occurs with exposures of 3000 R and higher producing a TCD 50/120 days of 5800 ± 1100 R. The cause of death in animals containing persisting tumors could be attributed to extensive pulmonary metastases and/or intercurrent infection relative to ulceration and necrosis of the tumor. The major advantages of the use of the Syrian hamster and the cervical carcinoma as a model system and as an interface for the comparison of data from other established tumor models with that from transplantable xenogenic tumor systems is also presented.