Yang Lin, Chen Hong, Zhao Miao, Peng Peng
Department of Gastroenterology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China.
Oncotarget. 2017 Jun 20;8(25):40214-40221. doi: 10.18632/oncotarget.16597.
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. 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. 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 showed that 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 identified as an independent factor for better OS. 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.
众多研究表明，循环中的总25-羟基维生素D（25(OH)D）与结直肠癌患者的生存率之间存在显著正相关。此外，还发现血浆维生素D与维生素D结合蛋白（VDBP）的浓度也显著相关。然而，尚无文献阐明VDBP、游离及生物可利用的25(OH)D在结直肠癌发生中的预后价值。本研究的目的是全面评估VDBP、总25(OH)D、游离及生物可利用的25(OH)D在I-III期结直肠癌患者中的预后价值。本前瞻性研究共纳入206例结直肠癌患者。术前血浆总25(OH)D和VDBP浓度采用直接酶联免疫吸附测定法测量，白蛋白浓度采用贝克曼自动生化分析仪测量。游离及生物可利用的25(OH)D浓度根据血浆VDBP、总25(OH)D和白蛋白的浓度计算得出。使用X-title程序确定VDBP、总25(OH)D、游离及生物可利用的25(OH)D的最佳临界值。结果显示，单因素分析表明游离及生物可利用的25(OH)D升高与更好的5年总生存率（OS）显著相关。通过多因素Cox分析，我们还发现游离25(OH)D水平高（HR = 0.442，95%CI = 0.238 - （此处原文有误，应为0.819）0.819，P < 0.010）可被确定为OS更好的独立因素。总之，我们的研究表明，I-III期结直肠癌患者中较高水平的游离及生物可利用的25(OH)D与更好的OS相关。此外，游离25(OH)D可被视为OS的独立预后生物标志物。
