Objective: Little is known about the etiology of small bowel carcinoid tumor (SBC), but a few studies have pointed to certain medical and lifestyle factors as potential risk factors. This study aims to evaluate these findings and to identify new associations.
Methods: A population-based European multicenter case-control study was conducted from 1995 through 1997. Incident histologically verified 35-69 year-old SBC cases (n = 99) and 3335 controls were recruited; 84 cases and 2070 controls were interviewed.
Results: Ever being a smoker was associated with SBC (odds ratio = 1.9; 95% confidence interval 1.1-3.2) and increased risk estimates were seen for all smoking categories. SBC was associated with previous gallstone disease and ovariectomy, but only when these conditions occurred within two years prior to the SBC diagnosis. No association was seen for a history of cholecystitis, liver cirrhosis, ulcerative disease, or Crohn's disease. Intake of alcoholic beverages--as well as medical treatments with radioactive substances, hormones, or corticosteroid tablets--were not associated with SBC.
Conclusions: This study indicates that tobacco smoking is a risk factor for SBC. The associations with gallstone and ovarian diseases may be due to enhanced medical surveillance during the early phase of the cancer disease.