Risk-adjusted incidence rates for prostate cancer in the United States

Abstract

Background: Risk-adjusted incidence rates (RAIRs) are population-based cancer incidence rates that reflect those who have never had the cancer but are at risk of developing it. This study compares RAIRS with conventionally reported incidence rates for prostate cancer.

Methods: A retrospective cohort design was used, based on data from the Surveillance, Epidemiology, and End Results (SEER) registries, with focus on white and black malignant prostate cancer cases in the years 2000-2007. RAIRs use only the first primary cancer and adjust for cancer prevalence in order to obtain a better population-based measure of cancer risk.

Results: Conventionally reported prostate cancer incidence rates underestimate risk for white males by from 0.1% in the age group 40-49 to 20.1% in the age group 80 years and older. In black males, conventional rates underestimate risk by 0.2% in the age group 30-39 to 26.4% in the age group 80 years and older. Trends in RAIRs from 2000 to 2007 increased in the age group 30-49 (17.0% for whites and 14.8% for blacks), decreased in the age group 50-69 (-4.5% for whites and -5.9% for blacks), and decreased in the age group 70 and older (-15.8% for whites and -26.5% for blacks). Trends in RAIRs were similar or less pronounced than trends in conventional rates. The estimated number of cases in the United States in 2007 based on RAIRS was 9.0% greater for whites and 11.3% greater for blacks than when based on conventional rates.

Conclusion: Prostate cancer incidence rates that include second and later prostate cancer primaries and adjust for prevalence better reflect cancer burden, whereas, prostate cancer incidence rates that only include the first diagnosed case and adjust for prevalence better reflect cancer risk.