Age at first birth and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.


An early age at first full-term birth is associated with a reduction in the subsequent development of breast cancer among women in the general population. A similar effect has not yet been reported among women who carry an inherited BRCA1 or BRCA2 mutation. We conducted a matched case-control study on 1816 pairs of women with a BRCA1 (n = 1405) or BRCA2 (n = 411) mutation in an attempt to elucidate the relationship between age at first full-term pregnancy and the risk of developing breast cancer. Information about the age at first childbirth and other pregnancy-related variables was derived from a questionnaire administered to women during the course of genetic counselling. There was no difference in the mean age at first full-term birth in the cases and controls (24.9 years vs. 24.8 years; P = 0.81, respectively). Compared to women whose first child was born at or before 18 years of age, a later age at first full-term birth did not influence the risk of developing breast cancer (OR = 1.00 per year; 95% CI 0.98-1.03; P-trend = 0.67). Stratification by mutation status did not affect the results. These findings suggest that an early first full-term birth does not confer protection against breast cancer in BRCA mutation carriers. Nonetheless, BRCA mutation carriers opting for a prophylactic oophorectomy as a breast and/or ovarian cancer risk-reducing strategy should complete childbearing prior to age 40 when this prevention modality is most effective.

  • Ainsworth P
  • Bellati C
  • Chudley A
  • Couch F
  • Daly M
  • Domchek S
  • Eisen A
  • Eng C
  • Evans G
  • Fishman D
  • Foulkes WD
  • Friedman E
  • Garber J
  • Gershoni-Baruch R
  • Ghadirian P
  • Isaacs C
  • Karlan B
  • Kim-Sing C
  • Klijn J
  • Kotsopoulos J
  • Lemire E
  • Lubinski J
  • Lynch HT
  • McKinnon W
  • McLennan J
  • Merajver S
  • Meschino WS
  • Moller P
  • Narod SA
  • Neuhausen SL
  • Offit K
  • Olsson H
  • Osborne M
  • Pasche B
  • Pasini B
  • Provencher D
  • Randall S
  • Rayson D
  • Rennert G
  • Saal HM
  • Sun P
  • Tung N
  • Wagner T
  • Weitzel J
PubMed ID
Appears In
Breast Cancer Res Treat, 2007, 105 (2)