ArticleBMJ open diabetes research & care2019
Impact of glycemic traits, type 2 diabetes and metformin use on breast and prostate cancer risk: a Mendelian randomization study.
Article in BMJ open diabetes research & care, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 35 papers, 9 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
35 citing papers in PubMed, 9 syntheses or guidelines pooled it, 52 citations in OpenAlex.
- Type 2 diabetes mellitus and cancer: A systematic review and meta-analysis of Mendelian randomization studies.Frontiers in endocrinology · 2026Pooled it
- Review of Mendelian randomization studies on common male-specific diseases.Frontiers in endocrinology · 2025Pooled it
- Risk factors for prostate cancer: An umbrella review of prospective observational studies and mendelian randomization analyses.PLoS medicine · 2024Pooled it
- Breast cancer risk for women with diabetes and the impact of metformin: A meta-analysis.Cancer medicine · 2023 · on this mapPooled it
- Prognostic value of metformin in cancers: An updated meta-analysis based on 80 cohort studies.Medicine · 2022 · on this mapPooled it
- Linking Physical Activity to Breast Cancer Risk via the Insulin/Insulin-like Growth Factor Signaling System, Part 2: The Effect of Insulin/Insulin-like Growth Factor Signaling on Breast Cancer Risk.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2022Pooled it
- Systematic review of Mendelian randomization studies on risk of cancer.BMC medicine · 2022Pooled it
- Type 2 Diabetes and Cancer: An Umbrella Review of Observational and Mendelian Randomization Studies.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2021Pooled it
- Prevalent diabetes and risk of total, colorectal, prostate and breast cancers in an ageing population: meta-analysis of individual participant data from cohorts of the CHANCES consortium.British journal of cancer · 2021Pooled it
- Genetic Evidence Links Gestational Diabetes Mellitus to Increased ER-Negative Breast Cancer Risk Through a Mendelian Randomization Analysis.International journal of endocrinology · 2026Article
- Causal effects of circulating inflammatory proteins on colorectal cancer: a Mendelian randomization and Spatial transcriptomic study.Discover oncology · 2025Article
- Implications of obesity and insulin resistance for the treatment of oestrogen receptor-positive breast cancer.British journal of cancer · 2024Review
- The effect of SGLT2 inhibition on prostate cancer: Mendelian randomization and observational analysis using electronic healthcare and cohort data.Cell reports. Medicine · 2024Article
- Does metformin really reduce prostate cancer risk: an up-to-date comprehensive genome-wide analysis.Diabetology & metabolic syndrome · 2024Article
- Causal relationship between genetically determined plasma metabolites and skin cancer: a two-sample Mendelian randomization study.Archives of dermatological research · 2024Article
- Drug-target Mendelian randomization revealed a significant association of genetically proxied metformin effects with increased prostate cancer risk.Molecular carcinogenesis · 2024Article
- Article
- The causality between Type 2 diabetes and breast cancer: a bidirectional two-sample Mendelian randomization study.Future oncology (London, England) · 2024Article
- Genetic effect of metformin use on risk of cancers: evidence from Mendelian randomization analysis.Diabetology & metabolic syndrome · 2023Article
- Article
Corrections and comments
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Authors and funding
2 authors at 2 institutions in 2 countries.
Funding
Abstract
Objectives: Observational studies suggest glycemic traits and type 2 diabetes are positively associated, and metformin inversely associated with breast and prostate cancer risk. However, observational studies are susceptible to unmeasured confounding while studies of metformin use are also vulnerable to immortal time bias. The use of Mendelian randomization may reduce confounding due to random allocation of relevant genetic markers at birth, and may reduce immortal time bias (for metformin-related variants analysis) since the start of exposure is at birth. Research design and methods: We identified strong genetic predictors of fasting glucose, glycated hemoglobin, and type 2 diabetes from the Meta-Analyses of Glucose and Insulin-related traits Consortium and Diabetes Genetics Replication And Meta-analysis Consortium (n=140 595 for glucose; n=123 665 for HbA1c; n=898 130 for type 2 diabetes) and of Results: There was no association of fasting glucose (OR 1.03 per mmol/L, 95% CI 0.85 to 1.25), HbA1c (OR 1.02 per %, 95% CI 0.73 to 1.45), or type 2 diabetes (OR 0.98 per log odds, 95% CI 0.95 to 1.01) with breast cancer in BCAC, with similar findings from UK Biobank. There was no association of fasting glucose (OR 0.93 per mmol/L, 95% CI 0.73 to 1.17), HbA1c (OR 0.90 per %, 95% CI 0.58 to 1.40) or type 2 diabetes (OR 1.02 per log odds, 95% CI 0.97 to 1.07) with prostate cancer in PRACTICAL. No strong evidence was observed for Conclusion: Glycemic traits and type 2 diabetes unlikely cause breast and prostate cancer. Whether metformin can be repurposed for cancer prevention remains unclear.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.