ABSTRACT
Introduction Since the beginning of the twentieth century, worldwide collective contributions have led to considerable progress in the prevention of cancer. In the first half of the past century, cancer mortality rose from the ninth to the second most frequent cause of death in the United States. In part this rise could be explained by a population-aging effect, but it also became clear that a changing lifestyle contributed to a great extent to the cancer epidemic. Most striking was the dramatic increase in lung cancer incidence as a consequence of massive adoption of cigarette smoking, first by men and later by women. In the same period, leading clinicians recognized the importance of early diagnosis and treatment to reduce case fatality and improve cancer survival rates. The first early detection method, a cytological test on a cervical smear for the preclinical diagnosis of (precursor lesions of) cervical cancer was reported in 1943 by Papanicolaou and Traut and it has since been known worldwide as the Pap test. However, it took almost 30 years before the test was generally adopted in population screening programs. In the second part of the 20th century, the emphasis in cancer control shifted from a curative towards a preventive approach. It became clear that the marked decline in death rates observed in the Western world during the 19th century was mainly due to general improvements in standards of living. As a consequence, it was hoped that specific preventive measures would also influence cancer incidence and mortality rates, as the role of specific medical therapies in cancer control was rather limited. A milestone was the publication by Doll and Peto in 1981 of a table estimating the contribution of different agents to the risk of death by cancer as an indication for the potential of preventive action.
