Prognostic Value Of Circulating Vitamin D Binding Protein,Total,Free And Bioavailable 25-hydroxy Vitamin D In Patients With Colorectal Cancer

Background:Numerous studies have suggested that there was a significantly positive association between circulating total 25-hydroxyvitamin D(25(OH)D)and survival in colorectal cancer patients.Moreover,plasma vitamin D was also found significantly associated with the concentration of vitamin D binding protein(VDBP).However,there was no paper to clarify the prognostic value of VDBP,free and bioavailable 25(OH)D in colorectal carcinogenesis.Aim:The aim of this study was to comprehensively assess the prognostic value of VDBP,total,free and bioavailable 25(OH)D in stage I-III colorectal cancer patients.Methods:A total of 206 colorectal cancer patients were enrolled in this prospective study.Preoperative plasma total 25(OH)D and VDBP concentrations were measured by direct enzyme-linked immunosorbent assay,and albumin concentration was measured by Beckman automatic biochemical analyzer.Free and bioavailable 25(OH)D concentrations were calculated based on the concentrations of plasma VDBP,total 25(OH)D and albumin.X-title program was used to determine the optimal cut-off values of VDBP,total,free and bioavailable 25(OH)D.Results:Elevated free and bioavailable 25(OH)D were significantly associated with better 5-year overall survival(OS)by univariate analysis.By multivariate cox analysis,we also found that the high level of free 25(OH)D(HR = 0.442,95%CI = 0.238-0.819,P<0.010)could be identfied as an independent factor for better OS.Conclusions:In conclusion,our study suggested that higher levels of free and bioavailable 25(OH)D were associated with better OS in stage I-III colorectal cancer patients.Moreover,free 25(OH)D could be considered as an independent prognostic biomarker for OS.