A Medical Mystery of the Best Kind: Major Diseases Are in Decline – The New York Times

Read article - Cites a paper by H. Gilbert Welch, professor of medicine, community and family medicine, and of the Dartmouth Institute for Health Policy and Clinical Practice, and Douglas Robertson, associate professor of medicine and of the Dartmouth Institute for Health Policy and Clinical Practice, which found that the rate of colon cancer deaths has fallen by nearly 50 percent since its peak in the 1980s. "The magnitude of the changes alone suggests that other factors must be involved," say Welch and Robertson. "None of the studies showing the effect of increased screening for colon cancer have indicated a 50 percent reduction in mortality, they wrote, "nor have trials for screening for any type of cancer."