[The influencing of rat-tail tumors with and without irradiation]

In a collective of 200 Wistar rats, the influence of anticoagulants upon the rat tail tumor (Walker 256 carcinosarcoma) was checked with and without irradiation. After implantation of the tumor and development of a certain definite tumor volume, the animals were divided into four different groups of 50 rats each. The first one was the control group without any manipulation, the second received an one-stage X-irradiation with 2500 R SD directed to the tail tumor, the third was treated with an oral dose of Phenprocoumon which was added to the daily drinking quantity (0.1 mg/kg body weight), and the fourth group was given an one-stage X-irradiation together with the oral Phenprocoumon treatment. The influence of these different treatments on the growth of the primary tumor, on the incidence of metastases and on the death rate was checked up. The best therapeutical effect was observed with combined radiation and Phenprocoumon treatment. The therapy resulted in an almost complete growth rate depression of the primary tumor, in an early tendency of remission of the primary tumor, a 42 per cent decrease of the incidence of metastases to the lung, and a 42 per cent increase of the survival rate. With regard to the frequency of metastases and to the survival rate, treatment with Phenprocoumon alone showed significantly better results as sole radiation treatment.