INTRODUCTION
Metformin, a first-line treatment for type 2 diabetes mellitus (T2DM), is increasingly recognized for its potential therapeutic relevance in dermatologic oncology. Beyond its effects on glycemic control, metformin modulates several key biologic pathways implicated in tumor development, including the activation of AMP-activated protein kinase (AMPK), inhibition of oxidative phosphorylation, reduction of oxidative stress, and suppression of proinflammatory and proliferative pathways. These mechanisms overlap with key drivers of cutaneous carcinogenesis, such as metabolic reprogramming, chronic inflammation, and immune evasion.1,2
As a result, metformin has garnered attention for its potential role in the prevention and treatment of both melanoma and nonmelanoma skin cancers (NMSCs). In basal cell carcinoma (BCC), early evidence suggests that metformin may enhance the efficacy of photodynamic therapy and reduce tumor risk. In melanoma, metformin has been shown to inhibit epithelial-mesenchymal transition and augment antitumor immune responses. By enhancing the effects of immune checkpoint inhibitors, such as PD-1 blockade, metformin may contribute to improved treatment outcomes.3
This review explores the emerging evidence supporting metformin's role in skin cancer prevention and management, with a focus on mechanistic pathways and context-specific clinical applications.
As a result, metformin has garnered attention for its potential role in the prevention and treatment of both melanoma and nonmelanoma skin cancers (NMSCs). In basal cell carcinoma (BCC), early evidence suggests that metformin may enhance the efficacy of photodynamic therapy and reduce tumor risk. In melanoma, metformin has been shown to inhibit epithelial-mesenchymal transition and augment antitumor immune responses. By enhancing the effects of immune checkpoint inhibitors, such as PD-1 blockade, metformin may contribute to improved treatment outcomes.3
This review explores the emerging evidence supporting metformin's role in skin cancer prevention and management, with a focus on mechanistic pathways and context-specific clinical applications.
MATERIALS AND METHODS
In April 2025, a structured literature review was conducted using PubMed to evaluate the effects of metformin on skin cancers, including melanoma and NMSCs. The search strategy employed combinations of the keyword "metformin" with terms such as "skin cancer," "melanoma," "basal cell carcinoma," "squamous cell carcinoma," and "nonmelanoma skin cancer." Eligible
