Hyperglycemia, a neglected factor during cancer progression.

Recent evidence from large cohort studies suggests that there exists a higher cancer incidence in people with type 2 diabetes (DM2). However, to date, the potential reasons for this association remain unclear. Hyperglycemia, the most important feature of diabetes, may be responsible for the excess glucose supply for these glucose-hungry cells, and it contributes to apoptosis resistance, oncogenesis, and tumor cell resistance to chemotherapy. Considering associations between diabetes and malignancies, the effect of hyperglycemia on cancer progression in cancer patients with abnormal blood glucose should not be neglected. In this paper, we describe the role that hyperglycemia plays in cancer progression and treatment and illustrate that hyperglycemia may contribute to a more malignant phenotype of cancer cells and lead to drug resistance. Therefore, controlling hyperglycemia may have important therapeutic implications in cancer patients.