Diabetes and breast cancer risk: a meta analysis

Peter Boyle, Mathieu Boniol, Alice Helene Marie Koechlin, Chris Robertson, Faustine Valentini, Kim Coppens, Laura-Louise Fairley, Magali Boniol, Tongzhang Zheng, Yawei Zhang, Markus Pasterk, Michel Smans, Maria Paula Curado, Patrick Mullie, Sara Gandini, Maria Bota, Geremia Bolli, Julio Rosenstock, Philippe Autier

Research output: Contribution to journalArticlepeer-review

163 Citations (Scopus)


The potential of an increased risk of breast cancer in women with diabetes has been the subject of a great deal of recent research.
A meta-analysis was undertaken using a random effects model to investigate the association between diabetes and breast cancer risk.
Thirty nine independent risk estimates were available from observational epidemiological studies. The Summary Relative Risk (SRR) for breast cancer in women with diabetes was 1.27 (95% Confidence Interval (CI), 1.16-1.39) with no evidence of publication bias. Prospective studies showed a lower risk (SRR 1.23 [95% CI, 1.12-1.35]) than retrospective studies (SRR 1.36 [95% CI, 1.13-1.63]). Type 1 diabetes, or diabetes in pre-menopausal women, were not associated with risk of breast cancer (SRR 1.00 [95% CI, 0.74-1.35] and SRR 0.86 [95% CI, 0.66-1.12] respectively). Studies adjusting for body mass index (BMI) showed lower estimates (SRR 1.16 [95% CI, 1.08-1.24]), as compared to those not adjusted (SRR 1.33 [95% CI, 1.18-1.51]).
Conclusions: The risk of breast cancer in women with type 2 diabetes is increased by 27% but not for women at pre-menopausal ages or with type 1 diabetes. BMI appears to be a potential confounder related to both diabetes and breast cancer.
Original languageEnglish
Pages (from-to)1608-1617
Number of pages10
JournalBritish Journal of Cancer
Issue number9
Early online date20 Sep 2012
Publication statusPublished - 23 Oct 2012


  • diabetes
  • breast cancer
  • meta-analysis
  • body mass indexd

Cite this