Association between smoking and colorectal cancer in Eastern Mediterranean Regional Office (EMRO): A systematic review and meta-analysis

Abstract

Background: Smoking poses a significant risk for colorectal cancer (CRC), considered the third leading reason for cancer-related deaths worldwide. However, there has been limited research on the relationship between smoking and CRC in the Eastern Mediterranean Regional Office (EMRO). Therefore, a meta-analysis was conducted to combine available data and gain a comprehensive understanding of the relationship between smoking and CRC in EMRO. Methods: Two independent researchers searched PubMed, Scopus, and Web of Science until December 2022. The included studies were checked for risk of bias administering the Newcastle-Ottawa scale. Heterogeneity was evaluated using I2 statistics and the Cochrane test. Publication bias was determined through funnel plot analysis and Egger’s regression test. Additionally, a meta-regression analysis explored the impact of a country’s Human Development Index (HDI) on the relationship between smoking and CRC. Results: The final analysis included 26 studies, revealing a significant association between smoking and CRC (OR = 1.40; 95% CI: 1.11 - 1.78; P = 0.004). Moreover, smoking had a more pronounced adverse effect on CRC in countries with higher HDIs compared to those with lower HDIs (OR = 1.30; 95% CI: 0.99 - 1.71; P = 0.054). Conclusions: Our findings underscore the importance of implementing smoking cessation programs and policies in EMRO countries, as they demonstrate a positive relationship between smoking and the risk of CRC. Furthermore, the results suggest that a country’s level of human development may influence the association between smoking and CRC. Further research is needed to investigate this potential connection and develop targeted public health interventions.

Family history of cancer as a potential risk factor for colorectal cancer in EMRO countries: a systematic review and meta-analysis

“…Environmental factors and dietary habits in this region may also contribute to an elevated risk of CRC in this region. According to a meta-analysis, smoking emerged as a significant risk factor for CRC in the EMRO region 60 . Seyyedsalehi et al, through a multicenter case–control study in Iran, identified a significant positive association between CRC and high dietary total fat intake 61 .…”

Epidemiologic profile of inflammatory bowel disease in Eastern Mediterranean Region (EMRO) countries: a systematic review and meta-analysis

“…Based on the epidemiological models, environmental factors can affect individuals based on a person's genetic characteristics, including age, gender, personality, and physical state, causing IBD susceptibility [10,12]. Eastern Mediterranean Regional Office (EMRO) includes 22 countries which is one of the World Health Organization regional classifications [13]. The epidemiology of IBD was studies in the EMRO countries separately but a comprehensive study to assess IBD epidemiology was lacking hence we performed a comprehensive metaanalysis study to investigated epidemiological status of IBD in this region.…”