Inhibition of tumor growth in a mouse fibrosarcoma after interleukin 2 application

Highly purified natural IL-2, obtained from induced human PBL's, was used to treat tumor-bearing mice. 3 X 10(6) vital cells of chemically induced fibrosarcoma BALB/c female Meth A were transplanted subcutaneously to female mice. Repeated injections of 10,000 U IL-2 into established tumors of 7-8 mm diameter led to complete rejections in 75% of the treated animals. Single intratumoral injections and other routes of the application of IL-2 did not significantly influence the tumor growth rate.