Production of Epithelial Tumours by a Combination of Beta Radiation and Painting with Benzpyrene

Abstract

In a previous paper (1) it has been shown that if mice be painted with 0.5 per cent solution of 3:4-benzpyrene¹ in benzol twice a week for ten weeks, and on the sixtieth day a dose of from 176 to 1584 r gamma radiation be applied, both benign and malignant tumours occur; no tumours follow painting for the same period without irradiation. In the present paper, this observation is extended to beta radiation, and the conditions for the formation of epithelial tumours by this double treatment are now more precisely defined.