Age at first full-term birth and breast cancer risk in BRCA1 and BRCA2 mutation carriers

Breast Cancer Res Treat. 2018 Sep;171(2):421-426. doi: 10.1007/s10549-018-4822-y. Epub 2018 May 17.


Purpose: In the general population, an early age at first full-term birth confers protection against the risk of developing breast cancer. The relationship between age at first birth and breast cancer risk is not clear for women with a mutation in the BRCA1 or BRCA2 gene. Thus, we undertook a case-control study of women with a BRCA1 or BRCA2 mutation to study the effects of age at first full-term birth matched for other reproductive factors.

Methods: Information about reproductive factors, including age at first birth as well as medical history, was collected from a routinely administered research questionnaire. There were 2,295 matched pairs of women with a BRCA1 or BRCA2 mutation included in the final analysis.

Results: There was no significant difference in the mean age at first full-term birth among the BRCA1 (24.9 vs. 25.2; P = 0.10) or BRCA2 mutation carriers (26.5 vs. 26.6 years; P = 0.80). Findings were similar in the analysis limited to cases who were diagnosed with breast cancer prior to age 45.

Conclusion: This matched analysis of a large number of BRCA mutation carriers suggests that age at first birth has little influence on BRCA1 or BRCA2 breast cancer risk.

Keywords: Age at first birth; BRCA1; BRCA2; Breast cancer.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Breast Neoplasms / epidemiology*
  • Breast Neoplasms / etiology*
  • Case-Control Studies
  • Disease Susceptibility
  • Female
  • Genes, BRCA1*
  • Genes, BRCA2*
  • Heterozygote*
  • Humans
  • Mutation*
  • Reproductive History*
  • Risk Assessment
  • Risk Factors
  • Young Adult