Proteinases reduce metastatic dissemination and increase survival time in C57Bl6 mice with the Lewis lung carcinoma.

The effect of combined proteolytic enzymes, administered by the rectal route, on the metastatic process and the time of survival in C57Bl6 mice with the Lewis lung carcinoma inoculated subcutaneously was investigated. In the control group, which received no enzyme treatment, 90% of animals died of the metastatic spread of cancer by day 18 after primary tumor extirpation. In Group A, which received the multi-enzyme solution from the time of primary tumor extirpation, 30% of mice died of disseminated cancer by day 25. In Group B, which was treated with the enzymes from 6 days before primary tumor extirpation, only 10% of animals showed the metastatic process by day 15. In Group C, which received the enzymes from 24 hours after intracutaneous tumor inoculation, no metastatic dissemination was discernible. In these three groups, the enzyme treatment was carried out throughout the study. None of the control animals survived for 100 days when the study was ended. The treated groups A, B and C showed survival rate 60%, 90% and 100% of animals, respectively, by 100 days.