title: Risk factors for carcinoma of the fallopian tube in women with and without a germline BRCA mutation.
abstract: OBJECTIVE
  The purpose of this study was to identify risk factors for fallopian tube cancer in women with and without a BRCA mutation.
  
  
  METHODS
  Subjects with fallopian tube cancer were identified from two sources: 1) a large international registry of women who carry a BRCA1 or BRCA2 mutation (n=56), and; 2) a population-based study of ovarian and fallopian tube cancer conducted in Ontario, Canada (n=66). BRCA mutation status was established for all subjects. Each subject was matched to one or more unaffected controls, for date of birth (within four years), for BRCA mutation status (negative, BRCA1, and BRCA2), for country of residence and for past history of breast cancer (yes/no). All subjects completed a questionnaire about medical history and lifestyle factors. Odds ratios and 95% confidence intervals were calculated for parity, oral contraceptive use, tubal ligation, hormone replacement therapy and body mass index, using conditional logistic regression.
  
  
  RESULTS
  We studied 103 women with fallopian tube cancer (48 with a BRCA1 mutation, 12 with a BRCA2 mutation and 43 with no identified BRCA mutation) and 980 matched controls. Increasing parity was associated with a decreased risk of fallopian tube cancer in non-carriers (trend per birth odds ratio 0.71 (95% CI 0.52-0.97), p=0.03), in BRCA1 carriers (OR=0.79 (0.62-1.02) p=0.07) and in BRCA2 carriers (OR=0.62 (0.34-1.15), p=0.13), but was statistically significant only for non-carriers. Oral contraceptive use was associated with a reduced risk in BRCA1 carriers (trend per year of use odds ratio=0.91 (0.83-0.99), p=0.03) but not for non-carriers (OR=0.97 (0.87-1.09), p=0.64) or for BRCA2 carriers (OR=0.94 (0.80-1.11), p=0.47). Hormone replacement therapy was associated with an increased risk for fallopian tube cancer in all subjects (OR=1.07 (1.01-1.13), p=0.03), and in the subgroups stratified by mutation, however the association was not significant in the subgroups. Tubal ligation was associated with a decreased risk of fallopian tube cancer for all subjects (OR=0.64 (0.31-1.28), p=0.21), however the reduction was not significant.
  
  
  CONCLUSIONS
  Parity and oral contraceptive use are associated with reduced risks of fallopian tube cancer. In contrast, hormone replacement therapy may be associated with an increase in the risk of fallopian tube cancer.
authors.affiliation: Women's College Research Institute, 790 Bay Street, Toronto, Ontario, Canada.
authors.forename: Danielle
authors.initials: D
authors.lastname: Vicus
authors.forename: Amy
authors.initials: A
authors.lastname: Finch
authors.forename: Barry
authors.initials: B
authors.lastname: Rosen
authors.forename: Isabel
authors.initials: I
authors.lastname: Fan
authors.forename: Linda
authors.initials: L
authors.lastname: Bradley
authors.forename: Ilana
authors.initials: I
authors.lastname: Cass
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
authors.forename: Beth
authors.initials: B
authors.lastname: Karlan
authors.forename: John
authors.initials: J
authors.lastname: McLaughlin
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005185:Fallopian Tube Neoplasms / Q000235:genetics*; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D008875:Middle Aged; D012042:Registries