Injection of mice bearing transplantable Sarcoma 37 with living and killed Candida species caused sloughing of the tumors in varying degrees (over 80 per cent with Candida guilliermondi). The intravenous route of administration proved the most effective. Heat- and chemically killed cultures, as well as crude filtrates, were active, though to a lesser degree. Several other organisms, e.g., Cryptococcus glabratus, Rhodotorula rubra, Torulopsis candida, Torulopsis utilis, and Pichia fermentans, were also effective. Some organisms were without effect on these tumors: Cryptococcus neoformans, Histoplasma capsulatum, Geotrichum album, Nocardia intracellularis. Response of the spontaneous tumors thus far tested has been very limited.
Following intravenous injection, there was widespread distribution of the organisms in normal tissues, as well as in tumors, but no evidence of destruction of cells other than those of the tumor was noted. No toxic symptoms developed in mice injected with nonpathogenic species in tumor-necrotizing doses.
Supported in part by a grant from the Eli Lilly Co. and in part by an institutional grant from the American Cancer Society.