Metformin & Esophageal Squamous Cell Carcinoma (ESCC)

Proposed mechanisms of risk reduction — click any node to open related literature

Metformin and ESCC: proposed mechanisms Flowchart of direct and indirect mechanisms by which metformin may reduce ESCC risk. Each node links to relevant PubMed literature. Metformin Mitochondrial complex I inhibitor Direct cellular effects Indirect systemic effects AMPK activation Disrupts energy metabolism ↓ mTOR & EGFR signaling Key ESCC oncogenic drivers Cell cycle arrest G1/S blockade in squamous cells ↓ PAH-induced DNA damage Reduces carcinogen adducts Apoptosis induction p53 & caspase activation ↓ NF-κB inflammation Key ESCC promoter suppressed Metabolic cofactor reduction Attenuates tobacco/alcohol risk Microbiome modulation Esophageal dysbiosis reversed ↓ IGF-1 & insulin Reduced squamous proliferation Epigenetic modulation AHRR methylation (HAP pathway) ESCC-specific context HAP, tobacco, alcohol, poor nutrition ↓ ESCC risk & mortality Incidence, progression, survival Direct cellular mechanisms Indirect systemic effects ESCC-specific context Click any node to open PubMed search

Figure: Proposed mechanisms by which metformin may reduce esophageal squamous cell carcinoma (ESCC) risk and mortality.
Based on Blechter et al. (2025), Environment International 205:109889, and supporting literature. Nodes link to PubMed searches for the relevant topic.

Note on evidence: Most mechanistic evidence comes from in vitro studies and observational data in diabetic populations. Randomized controlled trials of metformin for ESCC prevention in non-diabetic individuals are not yet available. Links open PubMed searches — results will reflect the current state of the indexed literature.

Key references

  1. Blechter B, et al. (2025). Exposure to household air pollution in relation to stomach and esophageal cancer in Xuanwei, China. Environment International, 205, 109889. doi:10.1016/j.envint.2025.109889
  2. Rahman ML, et al. (2025). Epigenome-wide association study of household air pollution exposure in an area with high lung cancer incidence. medRxiv. doi:10.1101/2025.04.03.25325041
  3. Blechter B, et al. (2023). Household air pollution and epigenetic aging in Xuanwei, China. Environment International, 178, 108041. PubMed
  4. Etemadi A, et al. (2023). Exposure to polycyclic aromatic hydrocarbons and incidence of esophageal cancer. JNCI, 116, 379. PubMed
  5. Portengen L, et al. (2023). Methylated PAHs from household coal use and lung cancer risk in Xuanwei. Environment International, 173. PubMed
  6. Vermeulen R, et al. (2019). Constituents of household air pollution and risk of lung cancer in never-smoking women in Xuanwei. Environmental Health Perspectives, 127. PubMed
  7. Abedi-Ardekani B, et al. (2010). PAH exposure in oesophageal tissue and risk of ESCC in Iran. Gut, 59, 1178–1183. PubMed
  8. Peters A, Nawrot TS, Baccarelli AA. (2021). Hallmarks of environmental insults. Cell, 184, 1455–1468. PubMed
  9. Agagündüz D, et al. (2023). Understanding the role of the gut microbiome in gastrointestinal cancer. Frontiers in Pharmacology, 14, 1130562. PubMed
  10. Rangraze I, et al. (2025). Metformin: A dual-role player in cancer treatment and prevention. Medicina, 61(6), 1021. PubMed
  11. Jin L, et al. (2021). Use of untargeted metabolomics to explore the air pollution-related disease continuum. Current Environmental Health Reports, 8, 7–22. PubMed