Spatial Analysis of Colorectal Cancer in Iran

Reza Pakzad,Asieh Moudi,Zahra Pournamdar,Abdollah Mohammadian-Hafshejani,Zohre Momenimovahed,Hamid Salehiniya,Iraj Pakzad,Farhad Towhidi,Behnam Reza Makhsosi

doi:10.7314/apjcp.2016.17.s3.53

Abstract

Colorectal cancer is one of the most common cancers. Due to demographic changes, it is predicted that the incidence of this cancer will increase. Variations of its incidence rate among geographical areas are due to various contributing factors. Since there have been a lack of studies on this topic in our country, the present assessment of spatial patterns of colorectal cancer incidence in Iran was performed. In this ecological study, the new cases of colon cancer were extracted from Cancer Registry Center report of the Health Deputy of Iran in 2009. The reported incidences of the disease were standardized on the basis of the World Health Organization population and the direct method. Then the data were inserted into the GIS software, and finally, using the analysis of hot spots (Getis-Ord Gi) high-risk areas were drawn. Provinces that are higher or lower than the national average (1.9 SD) were considered hot spots or cold spots, significant at the level of 0.05. A total of 6,210 cases of colorectal cancer were registered in Iran in 2009, of which 3,727 were in men and 2,783 in women (age-standardized rates of 11.3 and 10.9 per 100,000 population, respectively). The results showed that in central and northern Iran including Isfahan, Qom, Tehran, Qazvin and Mazandaran significant hot spots in men were present (p <0.05). In women also we have high incidence in northern and central states: Mazandaran province (p<0.01) and the province of Tehran (p<0.05) had higher incidences than the national average and were apparent as significant hot spots. Analysis of the spatial distribution of colorectal cancer showed significant differences between different areas pointing to the necessity for further epidemiological studies into the etiology and early detection.

Highlights

Cancer is a major public health problem in Iran and many other parts of the world (Organization, 2011; Pakzad et al, 2015a; Razi et al, 2015)
In 2009, a total of 6,210 cases of colorectal cancer occurred in Iran of which 2,783 were women and 3,727 were men
Our results showed that colorectal cancer has a higher incidence in northern and central provinces of country than the rest of areas most of the hot spots of the disease were in these regions

Summary

Introduction

Cancer is a major public health problem in Iran and many other parts of the world (Organization, 2011; Pakzad et al, 2015a; Razi et al, 2015). The results of the global distribution of colorectal cancer shows that the incidence and prevalence of colorectal cancer are very different in the world In some areas, this difference reaches to 25 times (Schottenfeld and Winawer, 1996; Parkin et al, 2001; Siegel et al, 2014). Various studies in developed and Western countries have showed that only 2-8% of colorectal cases happen in under 40 year old people (Bülow, 1980; Mitry et al, 2001). While this rate reaches to around 15 to 35 per cent in the Middle East and Asia (Sung et al, 2005; Ansari et al, 2006; Siegel et al, 2014)

Methods

Results

Conclusion