| Background: In many countries gastric cancer has the highest incidence among the gastrointestinal cancers and is
the second most common cancer in Iran. The aim of this study was to identify and map high risk gastric cancer regions
at the county-level in Iran. Methods: In this study we analyzed gastric cancer data for Iran in the years 2003-2010. Area-
to-area Poisson kriging and Besag, York and Mollie (BYM) spatial models were applied to smoothing the standardized
incidence ratios of gastric cancer for the 373 counties surveyed in this study. The two methods were compared in term
of accuracy and precision in identifying high risk regions. Result: The highest smoothed standardized incidence rate
(SIR) according to area-to-area Poisson kriging was in Meshkinshahr county in Ardabil province in north-western
Iran (2.4,SD=0.05), while the highest smoothed standardized incidence rate (SIR) according to the BYM model was
in Ardabil, the capital of that province (2.9,SD=0.09). Conclusion: Both methods of mapping, ATA Poisson kriging
and BYM, showed the gastric cancer incidence rate to be highest in north and north-west Iran. However, area-to-area
Poisson kriging was more precise than the BYM model and required less smoothing. According to the results obtained,
preventive measures and treatment programs should be focused on particular counties of Iran. |