Examining the Completeness of Breast Cancer Pathology Reports Registered in the Population-based Cancer Registration System and Spatial Analysis of the Incidence of this Cancer in Iran in 2016

Background: Breast cancer (BC) is a leading cause of cancer-related deaths among women worldwide, and its incidence has increased in Iran over recent years. Objectives: In this study, we aimed at assessing the completeness of BC pathology reports in the population-based cancer registration system and perform a spatial analysis of the incidence of this cancer in Iran in 2016 to help policymakers develop targeted interventions. Methods: We conducted a retrospective descriptive analysis, using secondary data from the Integrated Cancer Information Management System, and obtained 13789 BC pathology reports from all provinces in Iran in 2016. Pathology data, including tumor type, tumor site, tumor size, pathologic T stage, pathologic N stage, and tumor grade were examined for completeness by age group. Results: Pathology reports from 4000 women with BC in 2016 from across all provinces of Iran were selected for this study. The completeness of tumor type, tumor site, tumor size, pathologic T stage, pathologic N stage, and tumor grade increased with aging. In addition, the completeness of pathology reports varied across different variables. Accordingly, the tumor grade and pathologic T stage had the highest and lowest completeness rates (100 % versus 27.4%), respectively. Spatial analysis revealed significant high-risk areas for BC incidence, including Isfahan, Markazi, Chaharmahal and Bakhtiari, and Kohgiluyeh and Boyer-Ahmad provinces in central Iran. In contrast, North Khorasan was identified as a low-risk area. Conclusions: Considering the incompleteness of the pathology report in most of the tumor variables in the BC registry, we recognize the gaps to improve pathology data. To ensure effective interventions for BC control, tailored preventive measures are needed, particularly for high-risk areas. Continuous evaluation and data completion, including standard cellular pathology reports, are necessary for accurate BC control in Iran.