New toxicology: Carcinogenesis I

“Aude Sapere” “Dare to Know—Horace

Summary

The first part of this three-part series deals with the history of the recognition of the origins of cancer in specific, mainly chemical, environmental factors; and the rapid advances made this century in identifying carcinogens and elucidating their modes of action. I will then go on to review, briefly, the most important groups of carcinogenic chemicals, their in-vivo activation and common mode of action.

The second article will start with the cytotoxic drugs and demonstrate that the distinction between them and chemical carcinogens is arbitrary. I will also consider co-carcinogens and the carcinogenic action of UV light and the importance of these phenomena in understanding the genesis of cancer.

Finally, I will look at the linked processes of resistance to cytotoxic drugs, defences against carcinogens and DNA repair processes which it may be possible to turn to therapeutic advantage.