[Transplantation of gastrointestinal tumors to immunodeficient nude mice as an in vivo model of tumor biology].

Serial transplantation of ten different types of tumours, both primary tumours and their metastases, to 170 nude mice was conducted for biological analysis of human gastro-intestinal carcinomas, with particular reference being made to the aspect of tumour growth. The types transplanted included seven colorectal carcinomas, one oesophageal carcinoma, one gastric lymphoma, and two gastric carcinomas.--Tumour growth was quantitatively monitored by means of a standardised measuring method and was statistically evaluated. The qualitative aspects of tumour growth were micromorphologically investigated. Tumour transplants were allowed to reach a defined size and were then retransplanted within the nude mouse system, with up to six tumour passages being conducted. The investigations were evaluated, with particular reference being made to comparison between primary tumours, on the one hand, and their metastases, on the other.--The average primary tumour take rate amounted to 83 per cent and was generally higher for metastatic tumours. Statistically significant findings were obtained to the effect of growth of metastases which was faster than that of their own primary tumours (p 0.05), where as no qualitative differentiation between primary tumour and metastases was possible on the basis of the micromorphological aspect. Growth of metastases.