The effect of vitamin D supplementation on survival in patients with colorectal cancer: systematic review and meta-analysis of randomised controlled trials
A partir d’une revue systématique de la littérature (7 essais, 957 patients), cette méta-analyse évalue l’effet d’une supplémentation en vitamine D sur la survie chez des patients atteints d’un cancer colorectal
Background : Low circulating vitamin D levels are associated with poor colorectal cancer (CRC) survival. We assess whether vitamin D supplementation improves CRC survival outcomes. Methods : PubMed and Web of Science were searched. Randomised controlled trial (RCTs) of vitamin D supplementation reporting CRC mortality were included. RCTs with high risk of bias were excluded from analysis. Random-effects meta-analysis models calculated estimates of survival benefit with supplementation. The review is registered on PROSPERO, registration number: CRD42020173397. Results : Seven RCTs (n?=?957 CRC cases) were identified: three trials included patients with CRC at outset, and four population trials reported survival in incident cases. Two RCTs were excluded from meta-analysis (high risk of bias; no hazard ratio (HR)). While trials varied in inclusion criteria, intervention dose and outcomes, meta-analysis found a 30% reduction in adverse CRC outcomes with supplementation (n?=?815, HR?=?0.70; 95% confidence interval (CI): 0.48–0.93). A beneficial effect was seen in trials of CRC patients (progression-free survival, HR?=?0.65; 95% CI: 0.36–0.94), with suggestive effect in incident CRC cases from population trials (CRC-specific survival, HR?=?0.76; 95% CI: 0.39–1.13). No heterogeneity or publication bias was noted. Conclusions : Meta-analysis demonstrates a clinically meaningful benefit of vitamin D supplementation on CRC survival outcomes. Further well-designed, adequately powered RCTs are needed to fully evaluate benefit of supplementation in augmenting ‘real-life’ follow-up and adjuvant chemotherapy regimens, as well as determining optimal dosing.