An age–period–cohort analysis of cancer incidence among the oldest old, Utah 1973–2002

Abstract

We used age–period–cohort (APC) analyses to describe the simultaneous effects of age, period, and cohort on cancer incidence rates in an attempt to understand the population dynamics underlying their patterns among those aged 85+. Data from the Utah Cancer Registry (UCR), the US Census, the National Center for Health Statistics (NCHS), and the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) programme were used to generate age-specific estimates of cancer incidence at ages 65–99 from 1973 to 2002 for Utah. Our results showed increasing cancer incidence rates up to the 85–89 age group followed by declines at ages 90–99 when not confounded by the separate influences of period and cohort effects. We found significant period and cohort effects, suggesting the role of environmental mechanisms in cancer incidence trends between the ages of 85 and 100.

Keywords:

• age–period–cohort
• cancer
• oldest old
• morbidity deceleration
• ageing

Notes

1 Heidi A. Hanson is at the Department of Family & Preventive Medicine, and Pedigree & Population Resources, Huntsman Cancer Institute, University of Utah, 675 Arapeen, Salt Lake City, UT 84112, USA. E-mail: [email protected]. Ken R. Smith is at Pedigree & Population Resources, and Family & Consumer Studies, University of Utah. Antoinette M. Stroup is at the School of Public Health & Rutgers Cancer Institute of New Jersey, Rutgers University. C. Janna Harrell is at the Utah Cancer Registry, University of Utah.

2 We would like to acknowledge the invaluable assistance received with this project from Ruldoph Rull and Karim Al-Khafaji. The research reported here was supported by the Utah Cancer Registry (Contract No. HHSN261201000026C from the National Cancer Institute's SEER programme) and NIA grant ‘Early Life Conditions, Survival, and Health’ (RO1AG022095, Smith PI). Additional support was received from the Utah State Department of Health and the University of Utah.