Cited by 466Metabolism, Diabetes, and CancerCancer Risks and FactorsCancer, Lipids, and Metabolism

Long-Term Metformin Use Is Associated With Decreased Risk of Breast Cancer

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Bodmer, Michael, Meier, Christian, Krähenbühl, Stephan, Jick, Susan S., Meier, Christoph R.·2010·Diabetes Care

Abstract

OBJECTIVE: To evaluate whether use of oral hypoglycemic agents is associated with an altered breast cancer risk in women. RESEARCH DESIGN AND METHODS: Using the U.K.-based General Practice Research Database, we conducted a nested case-control analysis among 22,621 female users of oral antidiabetes drugs with type 2 diabetes. We evaluated whether they had an altered risk of breast cancer in relation to use of various types of oral hypoglycemic agents. Case and control patients with a recorded diagnosis of type 2 diabetes were matched on age, calendar time, and general practice, and the multivariate conditional logistic regression analyses were further adjusted for use of oral antidiabetes drugs, insulin, estrogens, smoking BMI, diabetes duration, and HbA1c (A1C). RESULTS: We identified 305 case patients with a recorded incident diagnosis of breast cancer. The mean ± SD age was 67.5 ± 10.5 years at the time of the cancer diagnosis. Long-term use of ≥40 prescriptions (>5 years) of metformin, based on 17 exposed case patients and 120 exposed control patients, was associated with an adjusted odds ratio of 0.44 (95% CI 0.24–0.82) for developing breast cancer compared with no use of metformin. Neither short-term metformin use nor use of sulfonylureas or other antidiabetes drugs was associated with a materially altered risk for breast cancer. CONCLUSIONS: A decreased risk of breast cancer was observed in female patients with type 2 diabetes using metformin on a long-term basis.

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  • The reduced risk of cancer and cancer mortality observed in studies of metformin users has been consistently in the range of 25% to 30%.

    “The reduced risk of cancer and cancer mortality observed in these studies has been consistently in the range of 25% to 30% [135-139,145-147].”
  • Patients with type 2 diabetes who are prescribed metformin had a lower risk of cancer compared to patients who did not take it.

    “Patients with type 2 diabetes who are prescribed metformin had a lower risk of cancer compared to patients who did not take it.”

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Authors
Bodmer, M., Meier, C., Krähenbühl, S., Jick, S. S., & Meier, C. R.
Affiliations
  • Denver Health Medical Center (US)
  • Boston University (US)
  • University Hospital of Basel (CH)
Corresponding author
Meier, Christoph R.
Venue
Diabetes Care
Published
2010-03-18
Volume
33
Issue
6
Pages
1304-1308
ISSN
  • 0149-5992 (ISSN-L)
  • 1935-5548
OpenAlex
W2121225884
Cited by
466
References
26
Citations by year
2026: 9 · 2025: 9 · 2024: 12 · 2023: 10 · 2022: 28 · 2021: 26 · 2020: 23 · 2019: 29 · 2018: 18 · 2017: 32 · 2016: 30 · 2015: 33 · 2014: 39 · 2013: 50 · 2012: 47
FWCI
21.87
Type
journal article
Language
en
Open access
Locations
  • Diabetes Care (publishedVersion, cc-by-nc-nd)
  • PubMed Central (publishedVersion, cc-by-nc-nd)
  • PubMed (publishedVersion)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Metabolism, Diabetes, and Cancer
  • Health Sciences › Medicine › Oncology › Cancer Risks and Factors
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Cancer, Lipids, and Metabolism
Keywords
metformin, breast cancer risk, type 2 diabetes, oral antidiabetic drugs, sulfonylureas, long-term drug use, women, chemoprevention
MeSH terms
Aged, Breast Neoplasms, Diabetes Mellitus, Type 2, Female, Humans, Hypoglycemic Agents, Metformin, Middle Aged, Time Factors, Odds Ratio, Case-Control Studies

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