The effects of interaction between familial and reproductive factors on breast cancer risk: A combined analysis of seven case-control studies

N. Andrieu, T. Smith, S. Duffy, D. G. Zaridze, R. Renaud, T. Rohan, M. Gerber, E. Luporsi, M. Lê, H. P. Lee, Y. Lifanova, N. E. Day

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18 Scopus citations


In this paper, a combined analysis was performed to study the interaction between familial risk and reproductive life factors. In particular, the interaction between familial risk and breast cell mitotic activity (BCMA), as assessed by duration of ovarian activity, was investigated because of the potential importance of mitotic activity on genetically susceptible cells. The present analysis included 3152 cases and 4404 controls in seven case-control studies from four countries. The interaction effect was estimated in each study separately, then combined using two different methods: a multivariate weighted average and a Bayesian random-effects model. The main effects of reproductive life factors on the risk of breast cancer were in agreement with the previous findings. In particular, an increased duration of BCMA before the first childbirth and over life was found to increase the risk of breast cancer (P < 0.001). Slightly increasing but nonsignificant, familial risks were observed with increasing number of children (P = 0.17), increasing age at first childbirth (P > 0.2) and increasing duration of BCMA (P > 0.2). There was no modification in familial risk with age at menarche and no clear pattern with menopause characteristics. A weak influence of reproductive and menstrual factors on the familial risk emerged from the present study.

Original languageEnglish (US)
Pages (from-to)1525-1536
Number of pages12
JournalBritish Journal of Cancer
Issue number9
Publication statusPublished - Jan 1 1998
Externally publishedYes



  • Breast cancer
  • Familial risk
  • Interactions
  • Reproductive life factor

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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