title: Coffee consumption and the risk of cutaneous melanoma: a meta-analysis.
abstract: OBJECTIVE
  Results from epidemiologic studies on coffee consumption and the risk of cutaneous melanoma are inconsistent. We conducted a meta-analysis to assess the associations between the consumption of total coffee, caffeinated coffee and decaffeinated coffee and the risk of cutaneous melanoma, respectively.
  
  
  METHODS
  A literature search was performed in PubMed, Web of Science and EMBASE for relevant articles published up to August 2015. Pooled relative risks (RRs) with 95 % confidence intervals (CIs) were calculated with a random-effects model. Dose-response relationship was assessed by restricted cubic spline.
  
  
  RESULTS
  Twelve studies involving 832,956 participants for total coffee consumption, 5 studies involving 717,151 participants for caffeinated coffee consumption and 6 studies involving 718,231 participants for decaffeinated coffee consumption were included in this meta-analysis. Compared with the lowest level of consumption, the pooled RRs were 0.80 (95 % CI 0.69-0.93, I (2) = 53.5 %), 0.85 (95 % CI 0.71-1.01, I (2) = 65.0 %) and 0.92 (95 % CI 0.81-1.05, I (2) = 0.0 %) for the consumption of total coffee, caffeinated coffee and decaffeinated coffee, respectively. In subgroup analysis by study design, the pooled RRs in cohort studies and case-control studies were 0.83 (95 % CI 0.72-0.97) and 0.74 (95 % CI 0.51-1.07) for total coffee consumption, respectively. Dose-response analysis suggested cutaneous melanoma risk decreased by 3 % [0.97 (0.93-1.00)] and 4 % [0.96 (0.92-1.01)] for 1 cup/day increment of total coffee and caffeinated coffee consumption, respectively.
  
  
  CONCLUSIONS
  This meta-analysis suggests that coffee consumption may reduce the risk of cutaneous melanoma.
authors.affiliation: Department of Epidemiology and Health Statistics, The Medical College of Qingdao University, No. 38 Dengzhou Road, Qingdao, 266021, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Oncology, Second Affiliated Hospital, The Medical College of Qingdao University, Qingdao, China.
authors.forename: Xutong
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Health Statistics, The Medical College of Qingdao University, No. 38 Dengzhou Road, Qingdao, 266021, China. zhangdf1961@126.com.
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Zhang
mesh_terms: D002110:Caffeine / Q000032:analysis; D003069:Coffee; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008545:Melanoma / Q000453:epidemiology* / Q000517:prevention & control; D012307:Risk Factors; D012878:Skin Neoplasms; D000096142:Cutaneous Malignant Melanoma
chemical_list: D003069:Coffee; D002110:Caffeine
keywords: Caffeinated coffee; Coffee; Cutaneous melanoma; Meta-analysis