aromatase inhibitor + metformin

The combination of an aromatase inhibitor (specifically exemestane or letrozole) and metformin (also known as dimethyldiguanide) was investigated as a potential therapeutic regimen for postmenopausal women with hormone receptor-positive (HR+) metastatic breast cancer. Aromatase inhibitors function by inhibiting the enzyme aromatase, which is responsible for the peripheral conversion of androgens into estrogens, thereby depriving estrogen-dependent tumors of their primary growth stimulus. Metformin, a biguanide primarily used for type 2 diabetes, was added to this regimen based on its ability to activate the AMP-activated protein kinase (AMPK) pathway and inhibit the mammalian target of rapamycin (mTOR) signaling, which are often dysregulated in breast cancer. Additionally, metformin reduces circulating insulin levels, which can otherwise promote tumor cell proliferation. A Phase II clinical trial (NCT01627067) led by Dr. Xichun Hu at Fudan University Shanghai Cancer Center evaluated this combination but found that the addition of metformin did not significantly improve progression-free survival compared to aromatase inhibitor therapy alone.

Other names

dimethyldiguanide + aromatase inhibitormetformin + AImetformin + exemestanemetformin + letrozoledimethyldiguanide + AI