Hidaka A, et al. - In this prospectively conducted study, researchers focused on the individual effects of insulin and blood glucose on risk of cancer in almost 4,000 cancer cases from a population-based cohort of 33,736 subjects. They examined the correlation of plasma C-peptide and glycated albumin (GA) with all-site and site-specific cancer risk by mutually accounting for their confounding effects. After adjustment for GA levels, a statistically significant association of highest levels of C-peptide with an increased risk of all-site, colon, liver, kidney, renal pelvis and ureter cancers was observed among men and women combined, vs the respective lowest levels. These findings suggest the possible relevance of higher insulin levels, independent of higher blood glucose levels, for DM-related carcinogenesis for several cancer sites. Even in those who have not developed DM, a reasonable option for assessing cancer risk is to evaluate circulating insulin levels.