Increased Incidence of Small Bowel Cancer in Females in Southeastern Kentucky

Abstract

Purpose: The annual U.S. incidence of small bowel cancer is 1.7 per 100,000 of the population from the years 1998–2002, with a slight male predominance. The median age at diagnosis is 67 years. The SEER data showed that most small bowel tumors occurred in older adults; over 90% of cases occurred in people over 40 years of age. Approximately 0.3% diagnosed were under 20, 1.9% between the ages of 20 and 34, 6.0% between 35 and 44, 15.6% between 45 and 54, 20.6% between 55 and 64, 24.9% between 65 and 74, 23.0% between 75 and 84 and 7.7% in those 85 years of age and older. The most common histological types of malignant tumors of the small intestine were: Adenocarcinoma- 45%; Carcinoid-29%; Lymphoma-15%; and Sarcoma-10%. Methods: A retrospective analysis of 39 cases of small bowel cancer was performed in the Southeast Appalachian region. Data was taken from the Perry County Tumor Registry for the years 1995–2003. Results: The estimated annual incidence was 14.7 per 100,000. The gender specific estimated annual incidence rates were 4.7 per 100,000 for males and 24.3 per 100,000 for females. The median age of diagnosis was 58 years, with 84.6% females and 15.4% males. Additionally, 15% of cases were 45 years of age or younger and 20% of cases had a history of smoking. The distribution of histological types were: adenocarcinoma 64% (M-66.6%, F-63.6%), carcinoids 18% (M-16.7%, F-18.2%), lymphomas 10% (M-16.7%, F-9%) and leiomyosarcoma 8% (M-0%, F-9%). Conclusions: Our results demonstrate that the median age of diagnosis of small bowel cancer is lower in Southeastern Appalachian Kentucky than that of the US (58 years and 67 years, respectively). Interestingly there was a greater incidence of small bowel tumors in females (24.3 per 100,000) in a region with a predominantly white population (90% of population). Additionally, greater number of bowel cancers attributable to adenocarcinoma among these individuals was observed (64%) compared to the (45%) for the US. Our findings of higher incidence of small bowel tumors particularly adenocarcinomas among females in Southeast Appalachian Kentucky region deserve further investigation.