# Investigating the causal link between metformin and lung cancer risk: a two-sample mendelian randomization analysis

## TL;DR

This study uses genetic data to investigate whether metformin, a diabetes drug, may reduce the risk of lung cancer.

## Contribution

The study provides new evidence of a potential causal link between metformin and reduced lung cancer risk using Mendelian randomization.

## Key findings

- Metformin is associated with a decreased risk of lung cancer (OR = 0.249).
- Sensitivity analyses confirm the results are robust with no significant heterogeneity or pleiotropy.

## Abstract

Lung cancer ranks as the most prevalent malignancy worldwide. Current studies have found that metformin is associated with the occurrence of lung cancer. Nevertheless, these results are not consistent. This study seeks to explore the potential causal connection among them utilizing a two-sample Mendelian randomization (MR) approach. Genome-wide association studies (GWAS) databases were subjected to data mining in order to detect single nucleotide polymorphisms (SNPs) closely related to metformin and lung cancer, which served as instrumental variables (IVs). MR analysis was performed primarily employing the inverse variance weighted (IVW) method. The relationship between them was assessed through odds ratios (ORs). The IVW method demonstrated that there was a substantial association between metformin and a decreased risk of lung cancer (OR = 0.249, 95% CI: 0.065–0.950, P = 0.041) when metformin was considered as the exposure factor. The results’ credibility was confirmed by additional sensitivity analyses that showed no discernible horizontal pleiotropy or significant heterogeneity. Our study indicates that metformin may help reduce the risk of lung cancer and emphasizes the significance of its role in lung cancer prevention.