Trends of Breast Cancer Incidence in Iran During 2004-2008: A Bayesian Space-time Model

Background: Breast cancer is the most frequently diagnosed cancer in women and estimating its relativerisks and trends of incidence at the area-level is helpful for health policy makers. However, traditional methodsof estimation which do not take spatial heterogeneity into account suffer from drawbacks and their results maybe misleading, as the estimated maps of incidence vary dramatically in neighboring areas. Spatial methods havebeen proposed to overcome drawbacks of traditional methods by including spatial sources of variation in themodel to produce smoother maps. Materials and
Methods: In this study we analyzed the breast cancer data inIran during 2004-2008. We used a method proposed to cover spatial and temporal effects simultaneously andtheir interactions to study trends of breast cancer incidence in Iran.
Results: The results agree with previousstudies but provide new information about two main issues regarding the trend of breast cancer in provinces ofIran. First, this model discovered provinces with high relative risks of breast cancer during the 5 years of thestudy. Second, new information was provided with respect to overall trend trends o. East-Azerbaijan, Golestan,North-Khorasan, and Khorasan-Razavi had the highest increases in rates of breast cancer incidence whilst Tehran,Isfahan, and Yazd had the highest incidence rates during 2004-2008.
Conclusions: Using spatial methods canprovide more accurate and detailed information about the incidence or prevalence of a disease. These modelscan specify provinces with different health priorities in terms of needs for therapy and drugs or demands forefficient education, screening, and preventive policy into action.