Diabetes mellitus is a rising global health issue, significantly impacting patient quality of life and survival. T2DM is associated with an elevated risk of various malignancies, including pancreatic, hepatic, colorectal, breast, and bladder cancers. The relationship between diabetes and cancer is bidirectional, with cancer treatments potentially inducing diabetes onset. The management of oncological patients with diabetes requires stringent glucose monitoring and a multidisciplinary approach involving both oncologists and endocrinologists to optimize therapeutic outcomes and enhance quality of life.