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ONCOLOGY, NUCLEAR MEDICINE AND TRANSPLANTOLOGY
Original Article
May 05, 2026 14 5

Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS

Daniel Obinna Eke 1 * ,
Jessica Awingosit Ayamyiya 2,
Katabaazi Lillian Mirembe 3,
Anthony Kosisochukwu Anyabuoke 4,
Jacqueline , Azodoh 5,
Gloria Oluwabukunmi Oladapo 6
1 Department of Nursing, Myrtle E. and Earl E. Walker College of Health Professions Maryville University of St. Louis, St. Louis, MO, USA2 Department of Cancer Clinical Trials O, University of Colorado Cancer Center Aurora, CO, USA3 Department of Pharmacovigilance Specialist, Feyti Medical Group, Kampala, Uganda4 Department of Lab Geneticist, Mayo Clinic, Rochester, MN, USA5 College of Pharmacy, Campbell University, Buies Creek, NC, USA6 Department of Pharmacology, University of Ibadan, Ibadan, Nigeria* Corresponding Author
Oncology, Nuclear Medicine and Transplantology, 2(2), 2026, onmt018, https://doi.org/10.63946/onmt/18529
Publication date: May 05, 2026
Full Text (PDF)

ABSTRACT

Type 2 diabetes mellitus is associated with an increased risk of several malignancies, prompting interest in the potential oncologic effects of antidiabetic therapies, particularly metformin. This study evaluated cancer-related adverse event reporting associated with metformin compared with other antidiabetic agents using real-world pharmacovigilance data from the FDA Adverse Event Reporting System (FAERS) between Q1 2023 and Q4 2024. A disproportionality analysis was conducted on over 3.2 million reports, including 66,187 metformin cases and 55,257 comparator cases comprising GLP-1 receptor agonists, SGLT2 inhibitors, sulfonylureas, and insulin. Reporting odds ratios (ROR), proportional reporting ratios (PRR), information components (IC), and chi-squared tests were applied across twelve pre-specified cancer types.
Metformin was associated with significantly lower reporting of hepatocellular carcinoma (ROR 0.377, 95% CI 0.181–0.782) and pancreatic carcinoma (ROR 0.669, 95% CI 0.493–0.908). In contrast, increased reporting signals were observed for prostate cancer (ROR 2.065, 95% CI 1.435–2.972), leukaemia (ROR 2.388, 95% CI 1.155–4.939), and breast cancer (ROR 1.404, 95% CI 1.023–1.926). Drug-specific comparisons indicated relatively lower overall cancer reporting for metformin compared with sitagliptin and empagliflozin, but higher reporting compared with insulin. Temporal analyses demonstrated variability in reporting patterns across study quarters.
These findings represent disproportionality signals reflecting reporting associations rather than causal effects and may be influenced by reporting bias, residual confounding, and differences in healthcare utilization. Overall, the results suggest a heterogeneous, cancer-type-specific reporting profile for metformin and highlight the value of pharmacovigilance analyses in generating real-world safety signals. Further confirmation in prospective and mechanistic studies is required.

KEYWORDS

Metformin Cancer Pharmacovigilance FAERS Disproportionality Analysis Reporting Odds Ratio Antidiabetic Agents Drug Safety

CITATION (Vancouver)

Eke DO, Ayamyiya JA, Mirembe KL, Anyabuoke AK, Azodoh J,, Oladapo GO. Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS. Oncology, Nuclear Medicine and Transplantology. 2026;2(2):onmt018. https://doi.org/10.63946/onmt/18529
APA
Eke, D. O., Ayamyiya, J. A., Mirembe, K. L., Anyabuoke, A. K., Azodoh, J. ,., & Oladapo, G. O. (2026). Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS. Oncology, Nuclear Medicine and Transplantology, 2(2), onmt018. https://doi.org/10.63946/onmt/18529
Harvard
Eke, D. O., Ayamyiya, J. A., Mirembe, K. L., Anyabuoke, A. K., Azodoh, J. ,., and Oladapo, G. O. (2026). Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS. Oncology, Nuclear Medicine and Transplantology, 2(2), onmt018. https://doi.org/10.63946/onmt/18529
AMA
Eke DO, Ayamyiya JA, Mirembe KL, Anyabuoke AK, Azodoh J,, Oladapo GO. Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS. Oncology, Nuclear Medicine and Transplantology. 2026;2(2), onmt018. https://doi.org/10.63946/onmt/18529
Chicago
Eke, Daniel Obinna, Jessica Awingosit Ayamyiya, Katabaazi Lillian Mirembe, Anthony Kosisochukwu Anyabuoke, Jacqueline , Azodoh, and Gloria Oluwabukunmi Oladapo. "Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS". Oncology, Nuclear Medicine and Transplantology 2026 2 no. 2 (2026): onmt018. https://doi.org/10.63946/onmt/18529
MLA
Eke, Daniel Obinna et al. "Cancer-Specific Disproportionality Signals Associated with Metformin Versus Other Antidiabetic Agents: A Real-World Pharmacovigilance Analysis of FAERS". Oncology, Nuclear Medicine and Transplantology, vol. 2, no. 2, 2026, onmt018. https://doi.org/10.63946/onmt/18529

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