Experimental production of carcinoma with cigarette tar. IV. Successful experiments with rabbits.

Abstract

Summary 1.Cigarette tar is carcinogenic to rabbit epithelium. Five of 41 rabbits painted with cigarette tar on the inner ear developed cancer. Two out of ten rabbits receiving an additional painting with croton oil once a week developed cancer. Four of these cancers were shown histologically to be squamous-cell carcinomas, one a carcinosarcoma, and two sarcomas. 2.Removing the basic portions of the tar does not seem to interfere with the carcinogenic activity of cigarette tar on rabbits. 3.Additional application of croton oil seems to have no significant influence on the development of cancer among rabbits receiving cigarette tar.