Albumin-to-alkaline phosphatase ratio: A novel prognostic index of overall survival in cholangiocarcinoma patients after surgery

AIM: To clarify the prognostic significance of preoperative albumin-to-alkaline phosphatase ratio (AAPR) in cholangiocarcinoma (CCA) subjects receiving surgery. METHODS: In this retrospective study, we included 303 CCA patients receiving surgery without preoperative therapy between 2002 and 2014. Clinicopathological characteristics (including AAPR) were analyzed to determine predictors of post-operative overall survival and recurrence-free survival (RFS). In addition, univariate and multivariate Cox proportional hazards models were conducted, followed by application of time-dependent receiver operating curves to identify the optimal cut-off. RESULTS: Univariate and multivariate analyses revealed both decreased overall survival [hazard ratio (HR): 2.88, 95%CI: 1.19-5.78] and recurrence-free survival (HR: 2.31, 95%CI: 1.40–3.29) in patients with AAPR < 0.41 compared to those with AAPR ≥ 0.41. The optimal cut-off of AAPR was 0.41. Of the 303 subjects, 253 (83.5%) had an AAPR over 0.41. The overall 1-, 3- and 5-year survival rates were 70.2%, 38.0% and 16.5%, respectively in the low (< 0.41) AAPR group, which were significantly lower than those in the high (≥ 0.41) AAPR group (81.7%, 53.9%, and 33.4%, respectively) (P < 0.0001). Large tumor size, multiple tumors, and advanced clinical stage were also identified as significant predictors of poor prognosis. CONCLUSION: Our outcomes showed that AAPR was a potential valuable prognostic indicator in CCA patients undergoing surgery, which should be further confirmed by prospective studies. Moreover, it is necessary to investigate the mechanisms concerning the correlation of low AAPR with poor post-operative survival in CCA patients.