Bird NTE, et al. - In patients undergoing attempted radical curative resection for hilar cholangiocarcinoma, researchers statistically evaluated the effect of postresectional tumor features on overall survival. They performed a meta-analysis of 24 articles, containing 4,599 patients, and found age, T category, lymph node involvement, microvascular invasion, perineural invasion and tumor differentiation as significant predictive factors with low heterogeneity. Portal vein resection and resection margin status also showed marked effects, but with high heterogeneity. The seventh edition of the AJCC classification does not include several tumor biological variables affecting overall survival, and these should be incorporated into prognostic models to ensure a tailored approach to prognostication and treatment.