Objective: To deter-mine the population-based incidence, anatomic distribution, and survival rates of gastrointestinal carcinoid tumors. Background: Carcinoid tumors arise from neuroendocrine cells and may develop in almost any organ. Many textbooks and articles represent single institution studies and report varying incidence rates, anatomic distribution of tumors, and patient survival rates. Population-based statistics remain largely unknown. Methods: Data was obtained from the National Cancer Institute Surveillance, Epidemiology, and End Results program (1973 to 1997). Incidence rates, distribution, and 5-year survival rates were analyzed. Multivariate Cox regression was used to identify predictors of survival using age, race/ethnicity, gender, and tumor characteristics (size, lymph node status, and stage). Results: Of the 11,427 cases analyzed, the average age was 60.9 years, and 54.2% were female. The overall incidence rates for carcinoid tumors have increased significantly over the past 25 years, although rates for some sites have decreased (eg, appendix). The gastrointestinal tract accounted for 54.5% of the tumors. Within the gastrointestinal tract, the small intestine was the most common site (44.7%), followed by the rectum (19.6%), appendix (16.7%), colon (10.6%), and stomach (7.2%). The 5-year survival rates for the most common gastrointestinal sites were stomach (75.1%), small intestine (76.1%), appendix (76.3%), and rectum (87.5%). Conclusions: Using national, population-based cancer registry data, this study demonstrates that (1) incidence rates for carcinoid tumors have changed, (2) the most common gastrointestinal site is not the appendix (as is often quoted), but the small intestine, followed in frequency by the rectum, and (3) survival rates differ between individual anatomic sites.
