Growth characteristics of the RL-67 lung tumor -- a new model for experimental therapy of metastatic processes

Implantation of the RL-67 tumor in to the limb muscle of C57Bl strain mice resulted in the tumor growth at the site of implantation and the metastatic process became manifest predominantly in the lungs of all animals. A direct correlation was established between the primary tumor and its metastases. The number of metastases on the 20th day after the transplantation amounted to about 60. The mean survival time of the tumor-bearing mice was approximately 24 days. Seven different substances were administered intraperitoneally to tumor-bearing animals and their effect on the tumor and its metastases was established. It was found out that heparin and carboxymethyldextran led approximately to a 50% decrease in the number of lung metastases in comparison with the controls. A certain "prophylactic" effect on metastases was achieved with Bleomycin. The data of the biological and histological studies suggested that the RL-67 lung tumor may be used as a suitable model for investigation of the factors influencing the tumor metastases.