The objective of this study was to conduct a systematic review and analyze the association between tobacco smoking and CRC from published papers during the previous five years. All published cohort studies within the last five years using specific keywords were reviewed. The title and abstract of all available papers were reviewed and considered for eligibility inclusion. | JOURNAL OF MEDICAL RESEARCH THE ASSOCIATION BETWEEN TOBACCO SMOKING AND COLORECTAL CANCER: A META ANALYSIS 1 Nguyen Thi Nga, 2Pham Phuong Lien, 3Khanpaseuth Sengngam, 4,5Le Tran Ngoan 1 Vinh Medical University, Vietnam; 2Hanoi University of Public Health, Vietnam; 3 National Institute of Public Health, Lao PDR; 4 International University of Health and Welfare, Japan; 5Hanoi Medical University, Vietnam Cigarette smoking is recognized as the cause of a number of diseases including cancer, however, previous findings of its relation to colorectal cancer (CRC) are inconsistent. The objective of this study was to conduct a systematic review and analyze the association between tobacco smoking and CRC from published papers during the previous five years. All published cohort studies within the last five years using specific keywords were reviewed. The title and abstract of all available papers were reviewed and considered for eligibility inclusion. The ln(HR) and se(ln(HR)) were estimated from the multivariable adjusted HR and the 95% confidence interval (CI) was derived from published studies. The random pooled multivariable adjusted HR and 95%CI was analyzed using STATA 10. There were 20 studies included for pooled analysis. The test for heterogeneity yielded Q = on 22 degrees of freedom (p = ). Moment-based estimate of between studies variance = . HR = ; CI ( - ), statistically significant, p < . We observed a significant positive association between tobacco smoking and the risk of colorectal cancer. Key words: CRC, cigarette smoking, cohort study, meta-analysis I. INTRODUCTION Cigarette smoking has been recognized as communicable diseases such as cardiovascular diseases, cancers, chronic respiratory the cause of a number of diseases including diseases and diabetes. Despite these negative cancer [1]. Annually, while active smoking kills health effects, the prevalence of tobacco more than five million people, .
