Incidence pattern and spatial analysis of breast cancer in Iranian women: Geographical Information System applicationsProfil d'incidence et analyse spatiale du cancer du sein chez les femmes iraniennes : utilisation des applications du Systeme d'information geographique

Background: Breast cancer is the leading cancer in Iranian women, but no studies have yet been conducted on the distribution and pattern of its incidence. Aim: To perform a spatial analysis and determine the incidence pattern of breast cancer in the Islamic Republic of Iran. Methods: This was a cross-sectional, pathology-based study of all new female patients with breast cancer registered in the Islamic Republic of Iran in 2011 (n=10 233). Initially, crude incidence rates were calculated for each province and the whole country per 100 000 person--years. Then, a direct standardization method and World Health Organization standard population were used to adjust for age effects on a geographical scale. Stata and Arc GIS software were used to calculate incidence rates and conduct spatial analysis. Results: The mean (standard deviation) age of the patients was 50.9 (12.6) years. The national age-standardized incidence rate for breast cancer in women was 29.88 per 100 000 person--years, with a range of 5-72 in different provinces. The clustering incidence pattern was observed in Mazandaran, Tehran, Alborz, Isfahan and Markazi Provinces (P < 0.01). There was a significant cluster of high incidence of breast cancer in Iranian women. Conclusion: These findings may help to establish etiological hypotheses of cancer causation and identify spatial anomalies in cancer incidence or registration in the Islamic Republic of Iran. Our findings may also aid further research on the possible explanations for these clusters and associations. Keywords: Cancer, incidence rate, incidence pattern, geographical information, system, Iran Citation: Ahmadi A; Ramazani R; Rezagholi T; Yavari P. Incidence pattern and spatial analysis of breast cancer in Iranian women: Geographical Information System applications. East Mediterr Health J. 2018;24(4):360-367. Contexte : Le cancer du sein est le cancer le plus répandu chez les femmes iraniennes, mais aucune étude n'a été réalisée à ce jour sur la distribution et le profil de son incidence. Objectif : Procéder à une analyse spatiale et déterminer le profil d'incidence du cancer du sein en République islamique d'Iran. Méthodes : Il s'agissait d'une étude transversale portant sur les caractéristiques pathologiques de toutes les nouvelles patientes atteintes d'un cancer du sein enregistrées en République islamique d'Iran en 2011 (n=10 233). Dans un premier temps, les taux bruts d'incidence ont été calculés pour chaque province et dans l'ensemble