The Decline in Cancer Incidence at Advanced Ages: Evidence from Cancer Registry Data for the Greater San Francisco Bay Area

Tim Miller, University of California, Berkeley

Armitage and Doll (1954) demonstrated that a multi-stage model of cancer origin (in which 5 or 6 mutational changes transformed normal cells to cancer cells) was consistent with their data showing a steep rise in cancer mortality with age. They restricted their analysis to the age groups 25 to 74 because data for older ages was considered unreliable. Subsequently, analysis of cancer data has been extended to older ages. In most published reports on cancer, the oldest-old are aggregated together in a single age group: ages 85 and older. The contribution of this study is to analyze cancer incidence data by single year of age, up to age 100, using cancer registry data for the Greater San Francisco Bay Area. A sharp linear decline in overall cancer risk for women and for men is observed from ages 85 to 100. Implications of this decline for human cancer biology are explored.