As a medical student in St. Louis, Wynder became interested in the link between cigarette smoking and cancer. The link had been noticed clinically, but there were no studies which proved it.
In 1950, he co-wrote an article in the Journal of American Medicine which clearly linked smoking to cancer, which the American Medical Association later called “landmark research.” In 1953, he found the culprit: “tar.” He also looked at other links to cancer, such as chemicals and diet, and founded the cancer research journal Preventive Medicine in 1976. Wynder died July 14 — of thyroid cancer. He was 77.