Impact of Vitamin D on the Colon Cancer Immune Microenvironment: Results of a Randomized Clinical Trial of Preoperative Vitamin D Supplementation in Patients with Stage I–III Colon Cancer
Menée à partir de l'analyse d'échantillons tumoraux et d'échantillons sanguins issus de patients atteints d'un cancer colique de stade I à III, cette étude examine l'effet d'une supplémentation préopératoire en vitamine D sur les cellules immunitaires du microenvironnement tumoral
Although vitamin D (VitD) exhibits antitumor activity in colorectal cancer preclinically, its effects in the human tumor microenvironment (TME) remain unclear. We conducted a randomized, placebo-controlled trial of preoperative high-dose VitD supplementation in patients with stage I to III colon cancer to assess its impact on the TME. Forty-two patients received either VitD3 (50,000 IU/day for 7 days, then 10,000 IU/day) or placebo before surgery. Spatial immune profiling and assessment of VitD receptor (VDR) and CYP27B1 expression were performed on paired tumor samples from 24 patients. VitD significantly increased plasma 25-hydroxyvitamin D levels (P < 0.001), increased CD3+CD8+ memory T cells (P = 0.03), reduced CD3+CD4+FoxP3+ regulatory T cells (P = 0.02), and spatially re-organized the TME, leading to greater T-cell and tumor cell proximity. Posttreatment VDR expression was heterogeneous and decreased overall (P = 0.02). Spatial transcriptomic profiling of posttreatment resections reflected predominantly repressive VDR activity. These findings support an immunomodulatory role for VitD, warranting further mechanistic investigation.
Cancer Discovery , résumé, 2026