Role of Polyoxyethylene Sorbitan Monostearate in Skin Carcinogenesis in Mice23

Abstract

A detailed record of tumors induced in mouse skin by repeated applications of polyoxyethylene sorbitan monostearate (Tween 60) with and without a prior single application of a carcinogenic hydrocarbon is reported. Most tumors induced subsequently regressed. Only a small proportion, approximately 3 percent, progressed to carcinomas. Tween 60, at a dose of 60 mg. administered twice weekly or daily, was effective as a promoting agent. When given alone at the same dosage, Tween 60 gave rise to an appreciable number of tumors, with a far longer latent period. The effects of dosage, different initiating agents, the interval between initiation and the Tween applications, and the individual caging of animals are described. The nature of the activity of Tween 60 is compared with croton oil and discussed.