The Etymology of Carcinogen
Carcinogen is a scientific compound coined in English around 1926 from two Greek elements: karkinos (crab) and -gen (producer, from genēs, born of, producing). The Greek karkinos was the standard medical term for malignant tumours, used by Hippocrates and Galen, who compared the swollen radiating veins around a tumour to the legs of a crab. Latin translated karkinos as cancer (which also means crab in Latin), and the same image still names the constellation and zodiac sign Cancer. So a carcinogen is, etymologically, a crab-maker — a producer of cancer. The word entered medical and toxicological vocabulary as researchers in the early 20th century began to identify specific environmental and chemical agents capable of inducing tumours in laboratory animals. The same Greek karkinos lies behind carcinoma (cancer of epithelial tissues), carcinology (the study of crustaceans), and the medical adjective carcinogenic. The Greek productive suffix -gen has been remarkably useful in scientific English, giving us oxygen, hydrogen, allergen, mutagen, antigen, and many more.