Increasing evidence highlights the possibility for approaches targeting metabolism as potential adjuvants to cancer therapy. Sodium-glucose transport protein 2 (SGLT2) inhibitors are the newest class of antihyperglycemic therapies and have recently been highlighted as a novel therapeutic approach to breast cancer. To our knowledge, however, SGLT2 inhibitors have not been applied in the neoadjuvant setting as a precision medicine approach to combining metabolic therapy with standard of care therapy for this devastating disease. In this study, we combine the SGLT2 inhibitor dapagliflozin with paclitaxel chemotherapy in both lean and obese mice. We show that dapagliflozin enhances the efficacy of paclitaxel, reducing tumor glucose uptake and prolonging survival in an insulin-dependent manner in some but not all breast tumors. Our data find a genetic signature for breast tumors most likely to respond to dapagliflozin in combination with paclitaxel. Tumors driven by mutations upstream of canonical insulin signaling pathways are likely to respond to such treatment, whereas tumors driven by mutations downstream of canonical insulin signaling are not. These data demonstrate that dapagliflozin enhances the response to chemotherapy in mice with breast cancer and suggest that breast cancer patients with driver mutations upstream of canonical insulin signaling may be most likely to benefit from this neoadjuvant approach. A clinical trial is currently in preparation, with an application recently submitted for Yale Human Investigations Committee approval, to test this hypothesis in breast cancer patients.
Clinical application of mutational analysis in breast cancer patients: The relevance of PIK3CA analysis for precision medicine
