title: Passive Smoking and Risk of Colorectal Cancer: A Meta-analysis of Observational Studies.
abstract: We conducted this meta-analysis to explore the association between passive smoking and the risk of colorectal cancer. A literature search of online databases, including MEDLINE, EMBASE, the Cochrane Library, and Web of Science was performed up to June 30, 2015. A fixed-effects meta-analysis using Stata 12.0 was carried out to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for the associations. Eleven articles, including 6 case-control studies and 6 cohort studies, were included in our analysis according to inclusion and exclusion criteria. The pooled RR of all studies showed a statistically significant association between passive smoking and colorectal cancer (RR = 1.14; 95% CI = 1.05-1.24). Results of subgroup analysis showed a positive association between passive smoking and rectal cancer ((RR = 1.33; 95% CI = 1.15-1.53) and that male passive smokers were at greater risks of colorectal cancer (RR = 1.73; 95% CI = 1.37-2.19) than females. Results suggested that passive smoking is associated with an increased risk of colorectal cancer.
authors.affiliation: Xiangya Hospital, Central South University, Changsha, Hunan Province, China zihuac@yahoo.cn.
authors.forename: Chen
authors.initials: C
authors.lastname: Yang
authors.affiliation: Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Chang-Hao
authors.initials: CH
authors.lastname: Huang
authors.affiliation: Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Wei-Jie
authors.initials: WJ
authors.lastname: Yuan
authors.affiliation: Xiangya Hospital, Central South University, Changsha, Hunan Province, China.
authors.forename: Zi-Hua
authors.initials: ZH
authors.lastname: Chen
mesh_terms: D015179:Colorectal Neoplasms / Q000453:epidemiology*; D006801:Humans; D064887:Observational Studies as Topic; D012306:Risk; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution
keywords: cancer prevention; colorectal cancer; environmental tobacco smoke; meta-analysis; passive smoking