title: A pooled analysis of case-control studies of thyroid cancer. VII. Cruciferous and other vegetables (International).
abstract: OBJECTIVE
  To investigate the association between cruciferous and other vegetables and thyroid cancer risk we systematically reanalyzed the original data from 11 case-control studies conducted in the US, Asia, and Europe.
  
  
  METHODS
  A total of 2241 cases (1784 women, 457 men) and 3716 controls (2744 women, 972 men) were included. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated for each study by logistic regression models, conditioned on age and sex, and adjusted for history of goiter, thyroid nodules or adenomas, and radiation. Summary ORs for all studies combined were computed as the weighted average of the estimates from each study.
  
  
  RESULTS
  A decreased risk for the highest level of cruciferous vegetable intake, as compared to the lowest, was observed in Los Angeles, Hawaii, Connecticut, southeastern Sweden, Tromsø, and Switzerland; the OR were above unity in Japan and Uppsala, whereas no material association was found in northern Sweden, Italy, or Greece. The OR values for all studies combined were 0.87 (95% CI 0.75-1.01) for moderate and 0.94 (95% CI 0.80-1.10) for high cruciferous vegetables intake. The results were similar in studies from iodine-rich areas and endemic goiter areas, and were consistent when the analysis was restricted to papillary carcinomas and women. The summary OR values for vegetables other than cruciferous were 1.04 (0.88-1.22) for moderate and 0.82 (0.69-0.98) for high consumption.
  
  
  CONCLUSIONS
  This combined analysis indicates that cruciferous vegetables are not positively related to thyroid cancer risk. Their effect does not seem to be substantially different from that of other vegetables, which appear to be protective on this cancer.
authors.affiliation: Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bosetti
authors.forename: Eva
authors.initials: E
authors.lastname: Negri
authors.forename: Laurence
authors.initials: L
authors.lastname: Kolonel
authors.forename: Elaine
authors.initials: E
authors.lastname: Ron
authors.forename: Silvia
authors.initials: S
authors.lastname: Franceschi
authors.forename: Susan
authors.initials: S
authors.lastname: Preston-Martin
authors.forename: Anne
authors.initials: A
authors.lastname: McTiernan
authors.forename: Luigino
authors.initials: L
authors.lastname: Dal Maso
authors.forename: Steven D
authors.initials: SD
authors.lastname: Mark
authors.forename: Kiyoiko
authors.initials: K
authors.lastname: Mabuchi
authors.forename: Charles
authors.initials: C
authors.lastname: Land
authors.forename: Fan
authors.initials: F
authors.lastname: Jin
authors.forename: Gun
authors.initials: G
authors.lastname: Wingren
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Galanti
authors.forename: Arne
authors.initials: A
authors.lastname: Hallquist
authors.forename: Eystein
authors.initials: E
authors.lastname: Glattre
authors.forename: Eiliv
authors.initials: E
authors.lastname: Lund
authors.forename: Fabio
authors.initials: F
authors.lastname: Levi
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Linos
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
mesh_terms: D001937:Brassica / Q000009:adverse effects*; D016022:Case-Control Studies; D016001:Confidence Intervals; D004032:Diet / Q000009:adverse effects*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000209:etiology*