Cocarcinogenesis studies on mouse skin and inhibition of

SUMMARY-Various tobacco leaf and tobacco smoke components and related synthetic compounds were tested for cocarcinogenic activity on mouse skin by simultaneous and repeated application with benzo[a]pyrene. The potent tumor-promoting agent, phorbol myristate acetate, was also tested and showed pronounced cocarcinogenic activify. Linalyl oleate and linalyl acetate showed weak cocarcinogenic activity. Linalyl laurate and the three corresponding esters of borneol showed no cocarcinogenic activity. Administration of phenol, rutin, and morin resulted in a decreased tumor yield and/or delayed tumor appearance when compared to benzo[a]-pyrene administered alone.-J Nat Cancer Inst 46: 1039-1044,1971. ALTHOUGH the terms "tumor promotion " and "cocarcinogenesis " are at times interchangeably used, a distinct operational difference and, pos-sibly, mechanistic differences exist which various authors have attempted to clarify (1-3). Perhap