MTOR and breast cancer: This study also showed that metformin was most effective and inhibited the mTOR pathway under glucose starvation conditions; suggesting that it should be combined with inhibitors of the glycolytic pathway for more beneficial treatment of TNBC in diabetic patients.129 In view of the mechanistic evidence linking the anti-proliferative effect of metformin to glucose concentration in TNBC, it is natural to advocate stringent glucose level monitoring in BC patients with diabetes, particularly as the hyperglycaemic state may further fuel malignant cell proliferation.