title: Coffee consumption and bladder cancer: a meta-analysis of observational studies.
abstract: Controversial results of the association between coffee consumption and bladder cancer (BC) risk were reported among epidemiological studies. Therefore, we conducted this meta-analysis to clarify the association. Relevant studies were identified according to the inclusion criteria. Totally, 34 case-control studies and 6 cohort studies were included in our meta-analysis. The overall odds ratio (OR) with 95% confidence interval (CI) between coffee consumption and BC risk was 1.33 (95% CI 1.19 to 1.48). The summary ORs of BC for an increase of 1 cup of coffee per day were 1.05 (95% CI 1.03 to 1.06) for case-control studies and 1.03 (95% CI 0.99 to 1.06) for cohort studies. The overall ORs for male coffee drinkers, female coffee drinkers and coffee drinkers of both gender were 1.31 (95% CI: 1.08 to 1.59), 1.30 (95% CI: 0.87 to 1.96) and 1.35 (95% CI: 1.20 to 1.51). Compared with smokers (OR = 1.24, 95% CI: 0.91 to 1.70), non-smokers had a higher risk (OR = 1.72, 95% CI: 1.25 to 2.35) for BC. Results of this meta-analysis suggested that there was an increased risk between coffee consumption and BC. Male coffee drinkers and non-smoking coffee drinkers were more likely to develop BC.
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education &Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei. 430030, China.
authors.forename: Weixiang
authors.initials: W
authors.lastname: Wu
authors.affiliation: Hubei provincial center for disease control and prevention.
authors.forename: Yeqing
authors.initials: Y
authors.lastname: Tong
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education &Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei. 430030, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education &Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei. 430030, China.
authors.forename: Guangxia
authors.initials: G
authors.lastname: Yu
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education &Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei. 430030, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Wei
authors.affiliation: Key Laboratory of Environment and Health, Ministry of Education &Ministry of Environmental Protection, and State Key Laboratory of Environmental Health (Incubating), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, #13 Hangkong Road, Wuhan, Hubei. 430030, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
mesh_terms: D016022:Case-Control Studies; D003069:Coffee / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D017594:Publication Bias; D012306:Risk; D012737:Sex Factors; D001749:Urinary Bladder Neoplasms / Q000453:epidemiology* / Q000209:etiology*
chemical_list: D003069:Coffee