Incidence Trends of Gastroenteropancreatic Neuroendocrine Tumors in the United States.

BACKGROUND & AIMS: Although multiple studies have reported an increasing incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) over the past decades, there are limited national data on recent trends. Using a population-based registry, we evaluated GEP-NET incidence trends in the United States population from 1975 through 2012, based on age, calendar year at diagnosis, and year of birth.

METHODS: GEP-NET cases from 1975 through 2012 were identified from the most recent version of the Surveillance, Epidemiology, and End Results registry using histologic and site codes. We calculated overall annual incidence, age-adjusted incidence (number of cases per 100,000), annual percent change (APC), and average APC by 5-year age intervals. We also evaluated the incidence rates by age, period, and birth year cohorts.

RESULTS: We identified 22,744 patients with GEP-NETs. In adults 25-39 years old, GEP-NET incidence rates decreased from the mid-1970s to the early 1980s, then increased until 2012. In adults ages 40 years and older or young adults ages 15-24 years, incidence rates generally increased continuously from 1975 through 2012. Adults ages 40-69 years had the most rapid increases in average APC (approximately 4%-6% per year). Overall incidence rates were highest in adults 70-84 years old. Since the inception of the Surveillance, Epidemiology, and End Results registry, GEP-NET incidence has increased in consecutive birth cohorts.

CONCLUSION: The incidence of GEP-NET continues to increase-particularly in older adults. More recent generations have had higher GEP-NET incidence rates than more distant generations.