Urashima Mitsuyoshi, Okuyama Mai, Akutsu Taisuke, Ohdaira Hironori, Kaji Mutsumi, Suzuki Yutaka
Division of Molecular Epidemiology, Jikei University School of Medicine, 3-25-8, Nishi-Shimbashi, Minato-Ku, Tokyo 105-8461, Japan.
Department of Surgery, International University of Health and Welfare Hospital, 537-3 Iguchi, Nasushiobara, Tochigi 329-2763, Japan.
Cancers (Basel). 2020 Feb 4;12(2):347. doi: 10.3390/cancers12020347.
Vitamin D has been shown to suppress the growth of cancer cells. Cancer cells are believed to take up bioavailable 25-hydroxyvitamin D (25[OH]D) (i.e., not bound to vitamin-D-binding protein (DBP)) more efficiently than DBP-bound 25(OH)D. Our aim was to use this bioavailable 25(OH)D, rather than total 25(OH)D, as a biomarker of vitamin D deficiency to investigate whether vitamin D supplementation improves the relapse-free survival (RFS) of patients with digestive tract cancer from the esophagus to the rectum by conducting a post hoc analysis of the AMATERASU trial (UMIN000001977). The bioavailable 25(OH)D levels were calculated via an equation using data of serum total 25(OH)D, albumin, and DBP levels, and DBP genotypes (rs7041 and rs4588). We estimated bioavailable 25(OH) levels in 355 patients. In a subgroup of patients with low bioavailable 25(OH)D levels (<median) ( = 177), 5 year RFS was 77% in the vitamin D group vs. 58% in the placebo group (hazard ratio, 0.54; 95% confidence interval, 0.31-0.95; = 0.03), whereas no significant difference was seen in a subgroup of patients with high bioavailable 25(OH)D levels ( for interaction = 0.046). We hypothesize that vitamin D supplementation may be effective in improving RFS among digestive tract cancer patients with low bioavailable 25(OH)D levels.
维生素D已被证明可抑制癌细胞生长。据信，癌细胞比与维生素D结合蛋白（DBP）结合的25（OH）D更有效地摄取生物可利用的25-羟基维生素D（25[OH]D）（即不与DBP结合）。我们的目的是通过对AMATERASU试验（UMIN000001977）进行事后分析，使用这种生物可利用的25（OH）D而非总25（OH）D作为维生素D缺乏的生物标志物，来研究补充维生素D是否能改善从食管到直肠的消化道癌症患者的无复发生存期（RFS）。生物可利用的25（OH）D水平通过使用血清总25（OH）D、白蛋白、DBP水平以及DBP基因型（rs7041和rs4588）的数据的方程式来计算。我们估计了355名患者的生物可利用25（OH）水平。在生物可利用25（OH）D水平低（<中位数）的患者亚组（n = 177）中，维生素D组的5年RFS为77%，而安慰剂组为58%（风险比，0.54；95%置信区间，0.31 - 0.9；P = 0.03），而在生物可利用25（OH）D水平高的患者亚组中未观察到显著差异（交互作用P = 0.046）。我们假设补充维生素D可能对改善生物可利用25（OH）D水平低的消化道癌症患者的RFS有效。
