The rôle of chemical stimulation in the development of mammary tumors postulated clearly by Loeb1 in 1919 has been demonstrated experimentally by several investigators.2 The present report summarizes additional experiments on the effect of several different chemical stimulants (estrogenic hormones3) on the development of mammary carcinomas and of subcutaneous sarcomas in three different strains of mice.
As new features may be listed (1) the development of sarcomas at the sites of injections in nongenital tissues following treatment with estrogenic hormones4 which have formerly been considered specific stimulants to the genital tissues; (2) the production of mammary cancers in mice by four different estrogenic chemicals (theelin, keto-estrin benzoate, hydroxyestrin benzoate and equilin benzoate); (3) the production of mammary carcinomas in an inbred strain of mice which had previously been considered relatively cancer resistant.
One or two estrogenic chemicals have been injected for periods exceeding 125 days into
GARDNER WU, SMITH GM, STRONG LC, ALLEN E. EXPERIMENTAL PRODUCTION OF MALIGNANT GROWTHS IN MICE BY ESTROGENIC CHEMICALS. JAMA. 1936;107(9):656-657. doi:10.1001/jama.1936.02770350024009