Metformin use and survival in people with ovarian cancer: A population-based cohort study from British Columbia, Canada Original paper

Researched by:

  • Divine Aleru ID
    Divine Aleru

    User avatarI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.

    Read More

August 12, 2025

  • Drug Repurposing 
    Drug Repurposing 

    Drug repurposing involves identifying new therapeutic uses for existing drugs, offering a cost-effective and time-efficient pathway to enhance treatment options and address unmet medical needs.

  • Ovarian Cancer
    Ovarian Cancer

    Ovarian cancer is one of the most lethal cancers affecting women worldwide. Known for its "silent" progression, this disease often goes undetected until it reaches advanced stages, making early diagnosis crucial for improving survival outcomes. With a variety of subtypes, ovarian cancer presents unique challenges in both treatment and prevention. Recent advancements in research are shining a light on the importance of the microbiome, particularly how microbial imbalances in the gut and vaginal microbiota can influence cancer progression. Repurposed drugs such as metformin and innovative interventions like probiotics, microbiota transplantation, and intratumoral microbiota therapies offer promising new avenues for improving ovarian cancer treatment.

Researched by:

  • Divine Aleru ID
    Divine Aleru

    User avatarI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.

    Read More

Last Updated: 2025-08-12

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Divine Aleru

I am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.

What was studied?

This study investigates the relationship between metformin use and survival outcomes in patients diagnosed with ovarian cancer. It specifically explores how metformin, a common treatment for type 2 diabetes, impacts the prognosis of ovarian cancer patients. The study focuses on a large cohort of patients diagnosed between 1997 and 2018 in British Columbia, Canada, using time-dependent analysis methods to avoid immortal time bias. The aim is to determine whether metformin use improves survival rates for ovarian cancer patients, particularly in those with diabetes.

Who was studied?

The cohort consisted of 4,951 individuals diagnosed with ovarian cancer in British Columbia, Canada, between 1997 and 2018. Out of these, 711 patients had a history of diabetes, and 236 of them used metformin during the 12 months before diagnosis. The study also included non-diabetic patients, but a separate focus was placed on the diabetic subgroup to better assess the relationship between metformin use and ovarian cancer survival. The patients in the study were followed up until 2020, providing a long-term view of survival outcomes.

Most important findings

The study found that metformin use was associated with a 17% reduction in ovarian cancer-specific mortality across the full cohort, though this result was not statistically significant. However, a significant survival benefit was observed in the subgroup of diabetic patients, where metformin use was linked to a 29% reduction in ovarian cancer-specific mortality. The findings suggest that metformin’s effects may be more pronounced in diabetic patients, possibly due to the interaction between diabetes and cancer survival. Importantly, the study accounted for immortal time bias, which has affected previous studies. No statistically significant impact was found with cumulative duration of metformin use or by the type of metformin use (pre-diagnosis, continuing, or new use post-diagnosis), although trends indicated improved survival with continued use of metformin from pre-diagnosis.

Key implications

The findings from this study suggest that metformin could offer a survival benefit for ovarian cancer patients, particularly those with diabetes. The results call for further research, especially focusing on non-diabetic patients, to fully understand the role of metformin in ovarian cancer treatment. While the statistical significance in the full cohort was not achieved, the protective effects observed in the diabetic subgroup warrant further investigation, possibly through randomized controlled trials to mitigate potential confounding factors. Given the widespread use of metformin for diabetes management, its potential application in cancer therapy could provide a low-cost, easily accessible treatment option for ovarian cancer patients.

Ovarian Cancer

Ovarian cancer is one of the most lethal cancers affecting women worldwide. Known for its "silent" progression, this disease often goes undetected until it reaches advanced stages, making early diagnosis crucial for improving survival outcomes. With a variety of subtypes, ovarian cancer presents unique challenges in both treatment and prevention. Recent advancements in research are shining a light on the importance of the microbiome, particularly how microbial imbalances in the gut and vaginal microbiota can influence cancer progression. Repurposed drugs such as metformin and innovative interventions like probiotics, microbiota transplantation, and intratumoral microbiota therapies offer promising new avenues for improving ovarian cancer treatment.

Metformin

Metformin is a synthetic derivative of guanidine derived from the guanidine alkaloid of the plant Galega officinalis L. with significant hypoglycemic effects. It is a first-line antihyperglycemic agent due to its efficacy, low cost, and favorable safety profile.

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