Noh Y, et al. - According to preclinical data, dipeptidyl peptidase-4 (DPP-4) inhibitors may promote metastatic progression of preexisting cancer via nuclear factor erythroid 2 related factor 2 (NRF2) activation. Considering this finding, researchers conducted this population-based cohort study to determine the link between different glucose-lowering treatments, including DPP-4 inhibitors and metformin, both with potential NRF2 modulating effects, and new-onset metastatic cancer among 223,530 diabetic patients newly diagnosed with primary cancer during 2009-2011 in Korea. They found that, DPP-4 inhibitor therapy vs no-antidiabetic therapy was not related to a significant risk of cancer metastasis, regardless of patient age and sex, except after thyroid cancer. A decreased metastatic risk was observed with metformin treatment among type 2 diabetes patients with preexisting cancer.