Ma L, et al. - Using the Cox proportional hazards regression model, the researchers intended to examine the prognostic factors for operable biliary tract cancers (BTC). In this analysis, three hundred forty-one patients were included of which 166 (48.7%) were males and 175 (51.3%) were females. Findings revealed that older age, depth of tumor invasion, positive surgical margin status, lower hemoglobin levels, and elevated serum lactic dehydrogenase (LDH) level were correlated with poor survival in operable BTC patients. In patients with operable BTC and especially distal bile duct (DBD) carcinoma, serum LDH level is a cost-effective prognostic biomarker.