Alkaline Phosphatase-To-Albumin Ratio as a Prognostic Indicator in Pancreatic Ductal Adenocarcinoma after Curative Resection

Background: The prognosis of pancreatic ductal adenocarcinoma (PDAC) remains poor and the models for survival prediction in PDAC patients after curative resection are still limited. Preoperative alkaline phosphatase-to-albumin ratio (APAR), an original inflammation-based score, has been established to analyze the prognostic significance in PDAC. Therefore, in this study, we aim to formulate a valuable prognostic nomogram for PDAC following curative resection. Methods: A total of 354 patients with PDAC undergoing curative resection were retrospectively enrolled in this study. The prognostic value of APAR was analyzed in primary cohort containing 220 randomly selected PDAC patients with curative resection and prognostic nomogram incorporating APAR into the American Joint Commission on Cancer (AJCC) 8(th) edition was established to obtain superior discriminatory abilities. The predictive performance of APAR was further validated in another independent cohort of 134 PDAC patients. Results: Patients with higher serum APAR level were probable to sustain poorer overall survival (OS). Significant positive correlations were found between APAR and tumor site, and several serum biochemical indexes, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), etc. The results of multivariate analysis showed, APAR was also identified as an independent prognostic indicator for OS in both primary and validation cohorts (P=0.004, P=0.038, respectively). Compared with the AJCC 8(th) edition, the nomogram consisting of APAR, pathological differentiation and the TNM staging system of AJCC 8(th) edition showed superior predictive accuracy for OS. All these results were further verified in the validation cohort. Conclusions: APAR can be considered as a novel independent prognostic biomarker for PDAC following curative resection. One more accurate and advanced predictive model will be achieved via the incorporation of APAR into nomogram.