Incidence of Right and Left Sided Colon Cancer in Arkansas (1998-2007)

Abstract

Purpose: To understand the factors that account for rising incidence of right sided colon cancer in the state of Arkansas over the past decade. Methods: Cancer registry of Arkansas Department of Health was queried for age-adjusted incidence of colon cancer over two five year intervals (1998-2002 and 2003-2007). The data was further sorted based on right and left sided cancers and rural and urban distribution of cases. Results: Age-adjusted incidence of right sided colon cancer increased from 17.1* between 1998-2002 to 17.3 between 2003-2007. While incidence in urban Arkansas fell from 18.6 to 17.1, incidence in rural Arkansas increased from 15.6 to 17.7. Age-adjusted incidence of left sided colon cancer declined from 24.6 to 20.4. While incidence rates in urban Arkansas fell from 23.6 to 19.1, incidence rates in rural Arkansas declined from 25.5 to 21.8. Overall incidence of right and left sided colon cancer declined from 41.7 to 37.7. * All figures are reported as per 100,000 and are adjusted for U.S. 2000 Standard Million Population. Conclusion: Incidence of colon cancer has reduced significantly in Arkansas between 1999-2002 and 2003-2007. However, there is significant variation between incidence of right and left sided cancers especially in rural Arkansas. This difference may be attributed to reduced number of screening colonoscopies compared to sigmoidoscopies in rural compared to urban Arkansas. Also, this may reflect dearth of physicians adequately trained in performing adequate exam of the colon in rural Arkansas where often primary care physicians and family practice physicians perform a sizeable percentage of colonoscopies. Our findings suggest differences that may be considered in formulating targeted screening and other public health strategies to reduce disparities in colon cancer incidence.Table: Age-adjusted site-specific incidence of colorectal cancer in Arkansas 1998-2007