The carcinogenic action of dibenzcarbazoles

Abstract

The known carcinogenic hydrocarbons such as 1:2:5:6-dibenzanthracene usually produce primary malignant changes at the site of application. If they are painted on the skin, papillomata or epitheliomata are produced; if injected subcutaneously sarcomata are formed. The occupational cancers of the skin no doubt depend upon local action of the same kind, but the cancer of the bladder, which is found among chemical workers, arises in an organ which cannot come in direct contact with any external carcinogenic chemical agent. Cancer of the bladder is more frequent among operatives in chemical works than in the general population; those concerned with the manufacture of naphthylamines and benzidine seem to be most liable to this form of cancer (cf. Berenblum 1932; Hueper 1934). Tests of the carcinogenic activity of naphthylamines themselves, however, have given contradictory and unsatisfactory results and they do not produce cancer in animals when applied to the skin.