Emerging evidence reveals a complex connection between diabetes and increased cancer risk. Chronic hyperglycemia, insulin resistance, and low-grade inflammation create a metabolic environment that may promote tumor growth and progression. Certain cancers—such as those of the liver, pancreas, breast, and endometrium—show higher incidence in diabetic individuals. Shared lifestyle factors, oxidative stress, and the effects of diabetes medications further influence cancer susceptibility. Understanding these interlinked mechanisms is essential for early detection, prevention, and integrated management strategies. Collaborative care between endocrinologists and oncologists can help optimize outcomes through personalized risk assessment and lifestyle modification.