Ma X, et al. - Assuming that the oxidative stress affects cancer development via various mechanisms, researchers determined the level of 15-F_2t-isoprostane (15-F_2t-IsoP: an accurate marker of oxidative stress in humans) by enzyme-linked immunosorbent assay in the pre-diagnosis urine samples, collected at cohort enrollment, from 363 incident liver cancer cases and 725 individually matched controls to ascertain the correlation between urinary 15-F_2t-IsoP level and cancer risk. Findings revealed a positive association between a high urinary 15-F_2t-IsoP level and high liver cancer risk, suggesting that 15-F_2t-IsoP may be a promising biomarker for liver cancer risk. Results thus suggest giving a higher priority to people with sero-positive HBsAg and higher level of 15-F_2t-IsoP on future surveillance program of liver cancer.