The carcinogenic response in mice to the topical application of propane sultone to the skin.

The carcinogenic effects of limited and repeated skin applications of propane sultone were investigated in three strains of mice, CF1, C3H and CBah (a hairless strain). Propane sultone was shown to be carcinogenic when given as a single application of a 25% w/v solution in toluene and also following twice weekly application of a 2.5% w/v solution for up to 58 weeks. More limited exposure to 2.5% w/v solutions of propane sultone resulted in a few skin tumours, although the incidences were not statistically significant. Most neoplasms were papillomas or carcinomas, although a small number of mesenchymal tumours of dermal origin also developed. No skin neoplasms were found in any control mice. The skin application of propane sultone was associated with a statistically significant increase in the incidence of systematic neoplasia in CFl and C3H mice. The exposed CFl mice had a higher incidence of neoplasms of lymphoreticular and lung origin, while female C3H mice showed a higher incidence of mammary gland and uterine tumours. In mice exposed to beta-propiolactone as a positive control, neoplasms developed at the site of application but, there was no evidence of increased systemic neoplasis in contrast to the findings with ptopane sultone.