Albumin-to-alkaline phosphatase ratio as a novel prognostic indicator for patients undergoing minimally invasive lung cancer surgery: Propensity score matching analysis using a prospective database

Objectives: To evaluate prognostic significance of albumin-to-alkaline phosphatase ratio (AAPR) for patients undergoing video-assisted thoracoscopic surgery (VATS) lobectomy for non-small-cell lung cancer (NSCLC) by a propensity score-matching (PSM) analysis. Methods: This PSM study was conducted on the prospectively-maintained database in our institution between December 2013 and March 2015. Overall survival analyses and further subgroup analyses were both performed to distinguish the differences in postoperative survival between patients stratified by an optimal cutoff of AAPR. Multivariable Cox proportional hazards regression models were established to determine the independent prognostic factors. Results: There were 390 patients with operable NSCLCs included. An AAPR of 0.57 was identified as the optimal cutoff regarding to postoperative survival. Both overall survival (OS) and disease-free survival (DFS) in patients with AAPR <= 0.57 were significantly shortened compared to those in patient with AAPR > 0.57 (Log-rank P < 0.001). Patients with AAPR <= 0.57 had significantly lower rates of OS and DFS than those of patients with AAPR > 0.57 (P < 0.001). These differences still remained significant after subgroup analyses and PSM analyses. Multivariate analyses on the entire cohort and the PSM cohort commonly indicated that low preoperative AAPR could be an independent prognostic factor for unfavorable OS and DFS of resected NSCLCs. Conclusions: AAPR can serve as a novel risk stratification tool to refine prognostic prediction for surgical NSCLC. It may help surgeons to screen high-surgical-risk patients and further formulate individualized treatment schemes.