Background: Owing to its rarity, the published evidence on gastrointestinal (GI) carcinoid is often based on small series of patients or population-based studies regarding all neuroendocrine tumors. Here, we present a comprehensive epidemiological and survival analysis of the largest cohort of patients with GI carcinoid ever reported.
Patients and methods: Patients with histological diagnosis of GI carcinoid (n = 25 531) were identified from the Surveillance Epidemiology End Results (SEER) database (including 18 USA cancer registries and spanning the 1973-2009 time frame). Demographic and disease data were used for epidemiological and survival analyses.
Results: The incidence of GI carcinoid is steadily increasing over the past three decades at a rate higher than any other cancer [annual percentage change (APC) = 4.4, 95% confidence interval (CI) 4.0-4.8]. These patients have a higher risk of further primary tumor (standardized incidence ratio, SIR = 1.15, 95% CI 1.10-1.21), but also a reduced risk of skin melanoma (SIR = 0.64, 95% CI 0.41-0.95). Despite the overall favorable prognosis (5-year disease-specific and relative survival rate: 91.3% and 87.4%, respectively), the mortality rate is increasing over time (APC = 3.5, 95% CI 3.0-4.0) and the 5-year survival rate of patients dying of GI carcinoid (28.5%), though better than that reported for GI cancers in general (8.4%), cannot be considered satisfactory. Finally, a nomogram is provided to predict patient survival on the basis of clinico-pathological factors independently associated with prognosis at multivariate analysis.
Conclusions: These findings can be clinically useful for the management of patients with GI carcinoid and eagerly prompt the continuous effort to develop more effective therapeutic strategies against this slow-growing but chemoresistant tumor.
Keywords: SEER; carcinoid; epidemiology; gastrointestinal; population-based study; survival analysis.