title: Contralateral breast cancer in BRCA1 and BRCA2 mutation carriers.
abstract: OBJECTIVE
  To estimate the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers after diagnosis and to determine which factors are predictive of the risk of a second primary breast cancer.
  
  
  METHODS
  Patients included 491 women with stage I or stage II breast cancer, for whom a BRCA1 or BRCA2 mutation had been identified in the family. Patients were followed from the initial diagnosis of cancer until contralateral mastectomy, contralateral breast cancer, death, or last follow-up.
  
  
  RESULTS
  The actuarial risk of contralateral breast cancer was 29.5% at 10 years. Factors that were predictive of a reduced risk were the presence of a BRCA2 mutation (v BRCA1 mutation; hazard ratio [HR], 0.73; 95% CI, 0.47 to 1.15); age 50 years or older at first diagnosis (v <or= 49 years; HR, 0.63; 95% CI, 0.36 to 1.10); use of tamoxifen (HR, 0.59; 95% CI, 0.35 to 1.01); and history of oophorectomy (HR, 0.44; 95% CI, 0.21 to 0.91). The effect of oophorectomy was particularly strong in women first diagnosed prior to age 49 years (HR, 0.24; 95% CI, 0.07 to 0.77). For women who did not have an oophorectomy or take tamoxifen, the 10-year risk of contralateral cancer was 43.4% for BRCA1 carriers and 34.6% for BRCA2 carriers.
  
  
  CONCLUSIONS
  The risk of contralateral breast cancer in women with a BRCA mutation is approximately 40% at 10 years, and is reduced in women who take tamoxifen or who undergo an oophorectomy.
authors.affiliation: Centre for Research on Women' s Health, Women's College Hospital, Toronto, Ontario, Canada.
authors.forename: Kelly
authors.initials: K
authors.lastname: Metcalfe
authors.forename: Henry T
authors.initials: HT
authors.lastname: Lynch
authors.forename: Parviz
authors.initials: P
authors.lastname: Ghadirian
authors.forename: Nadine
authors.initials: N
authors.lastname: Tung
authors.forename: Ivo
authors.initials: I
authors.lastname: Olivotto
authors.forename: Ellen
authors.initials: E
authors.lastname: Warner
authors.forename: Olufunmilayo I
authors.initials: OI
authors.lastname: Olopade
authors.forename: Andrea
authors.initials: A
authors.lastname: Eisen
authors.forename: Barbara
authors.initials: B
authors.lastname: Weber
authors.forename: Jane
authors.initials: J
authors.lastname: McLennan
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
authors.forename: William D
authors.initials: WD
authors.lastname: Foulkes
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
mesh_terms: D000328:Adult; D017668:Age of Onset; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D010052:Ovariectomy; D011446:Prospective Studies; D012306:Risk; D013629:Tamoxifen / Q000627:therapeutic use
chemical_list: D013629:Tamoxifen