title: Age at menarche and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.
abstract: Age at menarche is a strong and consistent predictor of breast cancer risk in the general population, but has not been well studied in women with a family history of breast cancer. We conducted this study to examine whether the presence of a deleterious BRCA1 or BRCA2 mutation influences age at menarche and to investigate whether or not there is an association between age at menarche and the risk of breast cancer in BRCA1 or BRCA2 mutation carriers. The presence of a deleterious BRCA1 or BRCA2 mutation did not appear to influence a woman's age at menarche. A matched case-control study was conducted on 1311 pairs of women who have been identified to be carriers of a deleterious mutation in either the BRCA1 (n = 945 pairs) or the BRCA2 gene (n = 366 pairs). Information about age at menarche was derived from a questionnaire routinely administered to carriers of a mutation in either gene. Among women who carried a deleterious BRCA1 mutation, age at menarche was inversely associated with the risk of breast cancer (p trend = 0.0002). This association was not observed among BRCA2 mutation carriers (p trend = 0.49). Compared with BRCA1 carriers whose age at menarche was < or =11 years, women with a menarcheal age between 14 and 15 years old had a 54% reduction in risk (OR = 0.46; 95% CI 0.30-0.69). This study implicates early age at menarche as a determinant of breast cancer among women with a BRCA1 mutation.
authors.affiliation: Centre for Research in Women's Health, University of Toronto, Women's College Hospital, 790 Bay Street, 7th Floor, Totonto, Ontario M5G 1N8, Canada.
authors.forename: Joanne
authors.initials: J
authors.lastname: Kotsopoulos
authors.forename: Jan
authors.initials: J
authors.lastname: Lubinski
authors.forename: Henry T
authors.initials: HT
authors.lastname: Lynch
authors.forename: Susan L
authors.initials: SL
authors.lastname: Neuhausen
authors.forename: Parviz
authors.initials: P
authors.lastname: Ghadirian
authors.forename: Claudine
authors.initials: C
authors.lastname: Isaacs
authors.forename: Barbara
authors.initials: B
authors.lastname: Weber
authors.forename: Charmaine
authors.initials: C
authors.lastname: Kim-Sing
authors.forename: William D
authors.initials: WD
authors.lastname: Foulkes
authors.forename: Ruth
authors.initials: R
authors.lastname: Gershoni-Baruch
authors.forename: Peter
authors.initials: P
authors.lastname: Ainsworth
authors.forename: Eitan
authors.initials: E
authors.lastname: Friedman
authors.forename: Mary
authors.initials: M
authors.lastname: Daly
authors.forename: Judy E
authors.initials: JE
authors.lastname: Garber
authors.forename: Beth
authors.initials: B
authors.lastname: Karlan
authors.forename: Olufunmilayo I
authors.initials: OI
authors.lastname: Olopade
authors.forename: Nadine
authors.initials: N
authors.lastname: Tung
authors.forename: Howard M
authors.initials: HM
authors.lastname: Saal
authors.forename: Andrea
authors.initials: A
authors.lastname: Eisen
authors.forename: Michael
authors.initials: M
authors.lastname: Osborne
authors.forename: Hakan
authors.initials: H
authors.lastname: Olsson
authors.forename: Dawna
authors.initials: D
authors.lastname: Gilchrist
authors.forename: Ping
authors.initials: P
authors.lastname: Sun
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D005820:Genetic Testing / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008572:Menarche / Q000502:physiology*; D008598:Menstruation; D009154:Mutation; D012307:Risk Factors