Colorectal cancer occurrence in Iran: a systematic review and meta-analysis

Article type
Authors
Dolatkhah R1, Dastgiri S1, Somi MH2, Asvadi Kermani I1, Ghojazadeh M3, Asghari Jafarabadi M4, Farassati F5
1Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
2Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
3Liver and Gastrointestinal Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
4Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
5The University of Kansas Medical School, Molecular Medicine Laboratory, KUMC, Kansas City, KS, USA
Abstract
Background: Colorectal cancer (CRC) is the third most common cancer in Iran. The rising incidence and mortality rates of CRC demand a systematic approach toward a specific and national screening programs.
Objectives: The increasing trend of CRC incidence in Iran and the close relationship with the geographical location are the underlying reasons for this study. A system for collecting cancer data, in all cities and rural areas of the country, is an essential priority.
Methods: Eleven databases, including MEDLINE, EMBASE, SCOPUS, and four databases for articles in Persian were searched from April 2014 to October 2014. Additional data were obtained from an online survey of the Central Library of Tabriz Faculty of Medicine. In this systematic review and meta-analysis, we included studies reporting different measures of incidence, age-standardized incidence rates (ASR), and crude incidence rates (CR). All rates ( per 100,000 person-years) were standardized to the world standard population (Figure1).
Results: We analyzed a total of 43 studies, including 11 articles in Persian and 32 articles in English, from different provinces and geographical areas of Iran, in this study using comprehensive meta-analysis (CMA) software. For accuracy studies, we used ASRs and CRs for males and females with 95% confidence intervals (CIs). ASRs were obtained based on the random model and were 8.15 (95% CI 6.78 to 9.53) and 6.27 (95% CI 5.21 to 7.34), for males and females, respectively. The random CRs for males and females were 5.58 (95% CI 4.31 to 6.58) and 4.06 (95% CI 3.16 to 4.95) respectively.
Conclusions: We emphasize monitoring the burden of CRC, public awareness and attitudes towards cancer risk factors and prevention, and need for improved international systematic engagement research studies.
Key Words: Colorectal Cancer; Meta-Analysis; Epidemiology; Incidence.