Metformin Application in Colorectal Cancer Risk and Outcomes

Metformin is a biguanide widely prescribed for type 2 diabetes, with emerging evidence of its role in colorectal cancer prevention and treatment. Epidemiological studies have linked metformin use to reduced incidence of colorectal adenomas and cancers among diabetic populations. Beyond observational data, preclinical investigations have revealed multiple mechanisms by which metformin may modulate tumour biology, including activation of energy-sensing pathways, suppression of pro-growth signalling and induction of apoptosis. Clinical meta-analyses suggest improved overall survival in colorectal cancer patients receiving metformin as part of diabetic management, with particular benefit in PI3KCA-mutant tumours. Ongoing trials aim to clarify optimal dosing, combination strategies and patient subsets most likely to gain from metformin’s adjuvant potential, underlining its global significance as an affordable, well-tolerated anticancer agent.

Research from Nature Portfolio

A foundational study investigated how metformin transiently arrests colorectal cancer cell growth through two mechanistic routes: activation of an energy sensor kinase and increased production of reactive oxygen species. These pathways converge on suppression of a central nutrient-responsive complex and its downstream effectors, leading to cell cycle arrest without inducing cell death. The work also highlighted reductions in markers of tumour stem-like cells, suggesting metformin may impair tumour-initiating populations. The transient nature of growth inhibition emphasises the need for combinatorial approaches to achieve sustained anticancer effects.

Metformin Application in Colorectal Cancer Risk and Outcomes publication trend

The graph below shows the total number of articles in metformin application in colorectal cancer risk and outcomes across all publications each year (not limited to Nature Index journals).

Technical terms

AMPK (adenosine monophosphate-activated protein kinase): A cellular energy sensor that, when activated, inhibits anabolic processes and can suppress tumour growth.

mTOR (mechanistic target of rapamycin): A central kinase integrating nutrient and growth factor signals to regulate cell growth and proliferation.

Reactive oxygen species (ROS): Chemically reactive molecules containing oxygen that can induce cellular stress and signal transduction changes.

Phosphoproteomics: Large-scale study of phosphorylated proteins to elucidate signalling networks and drug responses.

PI3KCA-mutant: Cancer cells harbouring mutations in a catalytic subunit of a key lipid kinase, often driving growth signalling and therapeutic resistance.

Colony formation assay: An in vitro technique to assess the ability of single cells to grow into colonies, reflecting clonogenic survival.

References

1. Metformin therapy and risk of colorectal adenomas and colorectal cancer in type 2 diabetes mellitus patients: A systematic review and meta-analysis. Oncotarget (2016).
2. Metformin in colorectal cancer: molecular mechanism, preclinical and clinical aspects. Journal of Experimental & Clinical Cancer Research (2019).
3. Survival Benefits of Metformin for Colorectal Cancer Patients with Diabetes: A Systematic Review and Meta-Analysis. PLOS ONE (2014).
4. Metformin Improves Overall Survival of Colorectal Cancer Patients with Diabetes: A Meta‐Analysis. Journal of Diabetes Research (2017).
5. Metformin transiently inhibits colorectal cancer cell proliferation as a result of either AMPK activation or increased ROS production. Scientific Reports (2017).
6. Phosphoproteomic analysis of metformin signaling in colorectal cancer cells elucidates mechanism of action and potential therapeutic opportunities. Clinical and Translational Medicine (2023).
7. Additive Cytotoxic and Colony-Formation Inhibitory Effects of Aspirin and Metformin on PI3KCA-Mutant Colorectal Cancer Cells. International Journal of Molecular Sciences (2024).