Risk factors associated with gastroenteropancreatic neuroendocrine tumors in a cohort of 2.3 million Israeli adolescents.

We investigated whether obesity and sociodemographic factors at adolescence are associated with incident gastroenteropancreatic neuroendocrine tumors (GEP-NET).Our cohort included 2.3 million Israeli adolescents examined at ages 16 to 19 years between 1967 and 2010. The baseline database included sex, country of birth, residential socioeconomic status (SES), body-mass index (BMI) and height. Participants were followed through linkage with the National Cancer Registry up to 2012. We identified 221 cases of GEP-NET (66 pancreatic, 52 gastric, 39 rectal, 27 appendiceal, 23 small bowel and 14 colonic). Immigration from the Former Soviet Union (FSU) was associated with the risk of small bowel and rectal NET's, [Hazard Ratio (HR) 4.79, 95% Confidence Interval (CI) 1.37-16.76 and 3.43, 95% CI 1.20-9.83, respectively].Height >75th percentile and BMI ≥ 85th percentile were associated with increased risk of gastric NET (HR 2.25 95% CI 1.14-4.42 and HR 2.38, 95% CI 1.19-4.75, respectively). Female sex was associated with appendiceal NET (HR 2.30, 95% CI 1.06-4.96) while male gender was associated with an increased risk for NET of the small bowel [HR 4.72 (95% CI 1.10-20.41)].In conclusion, our findings suggest different risk factor associations with the various GEP-NETS: immigrants from the FSU were at increased risk for small bowel and rectal NET; increased height and weight were associated with the risk of gastric NET and females were at increased risk for appendiceal NET. Further focus on the FSU population is indicated in addition to studies verifying the association of BMI and height with gastric NET.