Effect of Estrogen on Insulin Resistance: Focus on Carcinogenesis, Tumor Growth, and Other Pathological Aspects

Estrogen plays a pivotal role in regulating metabolic processes, particularly in maintaining insulin sensitivity. However, its imbalance, as observed in conditions like menopause or polycystic ovary syndrome (PCOS), contributes to insulin resistance, which is a key driver of various pathological states, including carcinogenesis and tumor growth. This narrative review explores the complex interaction between estrogen, insulin resistance, and associated pathological aspects, with a focus on cancer development. Estrogen influences insulin signaling pathways, while insulin resistance fosters a pro-tumorigenic environment, especially in hormone-sensitive cancers like breast and endometrial cancer. Furthermore, the review discusses the impact of estrogen-insulin resistance interactions on other pathological conditions, such as cardiovascular diseases, non-alcoholic fatty liver disease (NAFLD), and PCOS, underscoring their cumulative burden on health. Therapeutic approaches, including estrogen replacement therapy (ERT), are evaluated in the context of managing insulin resistance and its associated risks, particularly concerning cancer progression. Despite advances, significant gaps remain in understanding the dual role of estrogen in metabolic dysfunction and carcinogenesis. This review highlights the need for further research into the estrogen-insulin resistance axis and its implications for personalized therapeutic strategies in cancer and metabolic disorders. Key words: Estrogen; Insulin Resistance; Carcinogenesis; Tumor Growth; Hormone Therapy; Metabolic Syndrome; Estrogen Receptor Signaling; Hyperinsulinemia; Breast Cancer; Polycystic Ovary Syndrome (PCOS); Non-Alcoholic Fatty Liver Disease (NAFLD); cardiovascular disease; Estrogen Replacement Therapy (ERT); Insulin-like Growth Factors (IGFs); Menopause