Abstract A113: Regional variations in esophageal cancer incidence rates by census region in the United States, 1999-2008

Background: U.S. national cancer incidence estimates show a dramatic increase in esophageal adenocarcinoma (EA) and a simultaneous steady decrease in esophageal squamous cell carcinoma (ESCC). However, it is unknown whether substantial regional variations exist due to previous data limitations. Using the combined resource of NPCR and SEER, which covered 89% of the U.S. population, we assessed whether regional rates and trends significantly deviated from national estimates.

Methods: From NPCR-SEER, we extracted cancer case counts and populations for whites aged 45-84 years by calendar year, histology, sex, and census region for the period 1999-2008. We calculated age-standardized incidence rates (ASRs), annual percent changes (APCs), and male-to-female incidence rate ratios (MFIRRs).

Results: This analysis included 65,823 EAs and 27,094 ESCCs diagnosed during 778 million person-years. We observed significant geographic variability in EA and ESCC incidence rates and trends by census region, especially in men diagnosed with EA. The highest male ASRs for EA were observed in the Northeast (17.7 per 100,000) and Midwest (18.1 per 100,000), both of which were significantly higher (p<0.001) than the national estimate (16.0 per 100,000). The APC for men with EA in the Northeast was 62% higher than the national estimate (3.19% vs. 1.97%, P<0.001). The MFIRR for each histology remained fairly constant across calendar time, despite changes in incidence rates.

Conclusion: National estimates of esophageal cancer are not generalizable to specific census regions of the US. The stable MFIRRs may indicate predominant factors affecting esophageal cancer incidence rates are similar in men and women. These results underscore the importance of examining geographic and sex disparities in esophageal cancer.

Citation Format: Jennifer Drahos, Manxia Wu, William F. Anderson, Katrina F. Trivers, Jessica King, Philip S. Rosenberg, Christie R. Eheman, Michael B. Cook. Regional variations in esophageal cancer incidence rates by census region in the United States, 1999-2008. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr A113.