[Municipal distribution and trend of the incidence of stomach cancer in the health area of León, Spain (1994-2008)].

Background: Stomach cancer is common and has a high mortality rate. The aim of this study was to analyze the incidence and trend of gastric cancer in the health area of León.

Methods: We designed an observational descriptive study that included patients enrolled in the Hospital Tumor Registry of the Centro Asistencial Universitario de León with a diagnosis of malignant neoplasm of the stomach (ICD 9-151, ICD10-C16) between 01/01/1994 and 12/31/2008 and resident in the health area of León. The population supplied by Spain's National Institute of Statistics was used as the denominator. The time trend was evaluated with a Poisson regression model. To study the spatial distribution, we estimated municipal relative risks (RR) smoothed by fitting the Besag, York and Mollié model and the posterior probability (PP) of RR>1 using bayesian methods.

Results: A total of 1680 cases were included. The average crude incidence rate was 40.0 new cases per 100,000 in men and 23.5 for women. The incidence decreased by 1.4% per year (men: 1.2%, women: 1.8%). The age adjusted rates (European standard population) decreased from 26.9 (1994-6) to 22.2 (2006-8) new cases per 100,000 population in men and from 13.3 to 9.5 in women. Three geographical areas showed a RR excess with a PP higher than 0.9.

Conclusions: The observed rates are among the highest in Spain and their declining trend is lower than expected. Some municipalities had an excess risk.