Diabetes mellitus (DM) is a common endocrine disorder that affects people worldwide. A significant body of clinical research has investigated the association between diabetes and cancer and has investigated potential causative factors. This review examined recent literature on the cancer risk in people with DM. Databases such as PubMed, Science Direct, Web of Science, EBSCO, and the Cochrane Library were searched. Articles were screened based on titles and abstracts using Rayyan QCRI, followed by a full-text evaluation. A total of 15 studies involving 1,080,106 diabetic patients with various types of cancer were included. Most studies found that DM is associated with an increased risk of cancer; however, some reported a lower risk for prostate cancer. This review highlights the potential association between diabetes and cancer, but many findings remain unclear and contradictory, emphasizing the need for further research to clarify the relationship between the two conditions.
