Inequalities in Cancer Distribution in Tehran; A Disaggregated Estimation of 2007 Incidence by 22 Districts

Background: Cancer is the third cause of death in Iran, with an increasing incidence projected for the next decade. This study aimed to provide a disaggregated viewpoint on cancer incidence in all 22 districts of Tehran, using the Geographic Information System (GIS). Identifying clusters of cancers may assist in recognizing the cause of the disease, visualizing patterns of cancer distribution, the potential disparities, and help in the provision of early detection programs and equitable, curative, and palliative services. Methods: According to the 2007 - 2008 Cancer Registry Data published by the Ministry of Health, there were 7948 new cancer cases diagnosed in Tehran. Data were collected from all pathology centers and hospitals, either public or private facilities, in Tehran. These were classified into 31 main categories according to the expert panels and available resources. The population of the districts and neighborhoods were obtained from the Iran Statistical Center and the Municipally of Tehran, respectively. Home addresses and phones were extracted from the database and imported to GIS. The Age-Standardized Rate (ASR) was calculated using both the new world standard population (2000 - 2025) and the Iran population. Results: Overall, the cancer incidence rate and ASR were 101.8 and 94.775 per 100,000 people, respectively. The maximum cancer incidence rates in both sexes were in districts 6, 3, 1, and 2, whereas, the maximum ASRs were in districts 6, 1, 2, and 3. District 6 accommodated the highest ASRs in both the sexes. Common cancers were breast, skin, colorectal, stomach, and prostate. The ASR in men and women were 129.954 and 114.546 per 100,000 population. Conclusion: This report provides an appropriate guide to estimate the cancer distribution within the districts of Tehran. Higher ASR in districts 6, 1, 2, and 3, warrant further research, to obtain robust population-based incidence data and also to investigate the background predisposing factors in the specified districts. [PUBLICATION ABSTRACT]