BACKGROUND: Small-bowel cancer is uncommon and, accordingly, little is known about the epidemiology of this malignancy, especially by race and subtype.
OBJECTIVE: The objective of this analysis was to describe the distribution of small-bowel cancer in the United States by demographic, pathological, and clinical features.
DESIGN: This study was retrospective in design.
SETTING: Data from 26 population-based cancer registries in the United States from 1995 to 2008 were used.
PATIENTS: Patients diagnosed with small-bowel cancer (topography codes C17.0–17.3 and C17.8–17.9) were included.
MAIN OUTCOME MEASURES: The primary outcomes measured were race- and histology-specific incidence (age-adjusted rate trends and age-specific rates) of small-bowel cancer.
RESULTS: A total of 56,223 men and women diagnosed with small-bowel cancer were identified. The overall age-adjusted incidence rates for small-bowel cancer were 26.1 in men and 17.7 in women. Neuroendocrine tumors were the most common histological types of small-bowel cancer in men and women, followed by carcinoma, lymphoma, and sarcoma. In comparison with whites, the rate of small-bowel cancer was 42% greater in black men, 46% greater in black women, 34% lower in Asian-Pacific Islander men, and 37% lower in Asian-Pacific Islander women. Rates of small-bowel cancer were 24% lower in Hispanic men and 15% lower in Hispanic women than rates in non-Hispanics. The excess of small-bowel cancer in blacks and the deficit in Asian-Pacific Islanders were attributable mainly to the incidence of adenocarcinoma and carcinoid tumors. The incidence of GI stromal tumor was significantly higher among Asian-Pacific Islanders.
CONCLUSIONS: This is one of the largest studies of small-bowel cancer to date. These cancer registry data showed substantial racial and ethnic variation in the incidence of histological subtypes of small-bowel malignancy that suggest possible etiologic diversity and/or disparities in detection.