Numerous papillomas and two malignant tumors were elicited in 101 strain mice treated once weekly with applications of acetone extracts of latices of ten species of Euphorbia after a single dose of DMBA in acetone. Of the species tested E. tirucalli was the most potent. Three papillomas were seen in 40 mice treated with DMBA only and three among 100 mice treated with latices only. These results indicate the presence of potent tumor-promoting agents in the latices. With one exception, there was good correlation between degree of epidermal hyperplasia and tumor-promoting effect.
The cost of this research was partly defrayed out of a Block Grant from the British Empire Cancer Campaign.