Diabetes and cancer: therapeutic implications

The growing coexistence of diabetes and cancer contributes substantially to global morbidity and mortality. Beyond the independent burden of each disease, their intersection introduces unique challenges, particularly in cardiovascular risk. Patients with diabetes, especially those with underlying diabetic cardiomyopathy (DbCM), are at increased risk for cancer therapy-related cardiac dysfunction (CTRCD). Yet, the interplay between DbCM and CTRCD remains underexplored despite clear evidence of overlapping mechanisms and heightened vulnerability in this population. DbCM and CTRCD share key pathophysiologic features, including oxidative stress, mitochondrial dysfunction, inflammation, fibrosis, and impaired calcium handling, which collectively reducing myocardial reserve during cancer therapy. Even in patients without overt DbCM, diabetes management complicates cancer care by influencing treatment tolerance and outcomes. Antidiabetic agents exert pleiotropic effects on both cardiac and oncologic pathways: insulin may worsen remodeling and potentially amplify tumorigenic signaling, whereas metformin and sodium-glucose cotransporter 2 inhibitors (SGLT2i) demonstrate promise for cardioprotection and modulation of cancer therapy responses. This review synthesizes the current evidence on shared pathobiology, highlights drug-drug interactions that may exacerbate cardiotoxicity and discusses therapeutic opportunities that could improve patient outcomes. Understanding the intersection of diabetes and cancer is essential for reducing cardiac complications in this high-risk population. Integrated management strategies should prioritize early risk stratification, interdisciplinary collaboration, and judicious selection of antidiabetic therapies with cardioprotective potential. Research gaps remain in defining optimal monitoring protocols, refining pharmacologic strategies, and developing tailored guidelines. Addressing these gaps is critical to advancing cardio-oncology care and improving survivorship for patients living with both diabetes and cancer.