title: Does the Frequency of Cholecystectomy Affect the Ensuing   Incidence of Gallbladder Cancer in Sweden? A Population-Based   Study with a 16-Year Coverage.
abstract: BACKGROUND
  Gallbladder cancer (GBC) is rare among the different gastrointestinal cancers with a significant global variation in incidence. High cholecystectomy rates on benign indications have been assumed to prevent the development of gallbladder cancer. The aim of the present study was to explore the relationship between the rate of cholecystectomy at different time periods and regions of the country and the annual incidence of GBC.
  
  
  METHODS
  Standardized cholecystectomy and GBC incidences for Swedish counties have been obtained from the Swedish national inpatient and National Cancer registries for the years 1998–2013. The incidences have been calculated for ages over 15 years and per 100,000 population. The relationships between cholecystectomy and GBC incidences have been analyzed using regression models. Correlation analyses were performed for the total cumulative incidence rates as well as the incidence rates calculated for the first and last 8 years of the entire study period.
  
  
  RESULTS
  Cholecystectomy rates ranged from 99 to 205 per 100,000 and year, and the GBC incidence from 2.3 to 5.1. Overall, we observed a slow but steady decline in cholecystectomy rates—as well as GBC incidences during the 16-year period. No significant correlation between the cholecystectomy rates and GBC incidences was seen.
  
  
  CONCLUSIONS
  This nationwide population-based study demonstrates substantial geographic differences in annual cholecystectomy rates without any significant inverse co-variation between cholecystectomy rates and the ensuing GBC incidence which would have supported the idea that frequent cholecystectomy affects the incidence of GBC.
authors.forename: R
authors.initials: R
authors.lastname: Noel
authors.forename: U
authors.initials: U
authors.lastname: Arnelo
authors.forename: L
authors.initials: L
authors.lastname: Lundell
authors.forename: G
authors.initials: G
authors.lastname: Sandblom
mesh_terms: D000368:Aged; D002763:Cholecystectomy / Q000706:statistics & numerical data*; D005260:Female; D005544:Forecasting; D005706:Gallbladder Neoplasms / Q000453:epidemiology / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D013548:Sweden / Q000453:epidemiology