title: Risk factors for medullary thyroid carcinoma: a pooled analysis.
abstract: OBJECTIVE
  To investigate risk factors for medullary thyroid cancer (MTC).
  
  
  METHODS
  We conducted a pooled analysis of 14 case-control studies from Europe, North America, and Asia, including 67 medullary cancers (43 women and 24 men) diagnosed in ten studies. Of the original 4776, we selected five controls per case matched on study, gender, and age. The pooled odds ratios (OR) were estimated using conditional logistic regression.
  
  
  RESULTS
  Education, weight, and body mass were not associated with MTC, but a significant positive relationship was seen with height (OR = 2.6 for highest vs lowest tertile). Significant excess risks were associated with a history of thyroid nodules (OR = 12), hypertension (OR = 2.3), gallbladder disease (OR = 4.3), and allergies (OR = 2.2). Among current smokers, a decreased risk of MTC was observed with increasing number of cigarettes. The risk was significantly elevated among women having a first birth after age 25 years, but no clear pattern emerged for other reproductive factors.
  
  
  CONCLUSIONS
  Although the number of MTC was small, we detected several significant associations, including prior thyroid and other diseases.
authors.affiliation: Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy. evanegri@marionegri.it
authors.forename: Eva
authors.initials: E
authors.lastname: Negri
authors.forename: Elaine
authors.initials: E
authors.lastname: Ron
authors.forename: Silvia
authors.initials: S
authors.lastname: Franceschi
authors.forename: Carlo
authors.initials: C
authors.lastname: La Vecchia
authors.forename: Susan
authors.initials: S
authors.lastname: Preston-Martin
authors.forename: Laurence
authors.initials: L
authors.lastname: Kolonel
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Kleinerman
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Mabuchi
authors.forename: Fan
authors.initials: F
authors.lastname: Jin
authors.forename: Gun
authors.initials: G
authors.lastname: Wingren
authors.forename: Arne
authors.initials: A
authors.lastname: Hallquist
authors.forename: Fabio
authors.initials: F
authors.lastname: Levi
authors.forename: Athena
authors.initials: A
authors.lastname: Linos
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Fraumeni
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001208:Asia / Q000453:epidemiology; D018276:Carcinoma, Medullary / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D005705:Gallbladder Diseases / Q000150:complications; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D009656:North America / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000209:etiology*; D016606:Thyroid Nodule / Q000150:complications