Association between Blood 25-Hydroxyvitamin D Levels and Survival in Colorectal Cancer Patients: An Updated Systematic Review and Meta-Analysis

• Published in: Nutrients Vol. 10; no. 7; p. 896
• Main Authors: Maalmi, Haifa, Walter, Viola, Jansen, Lina, Boakye, Daniel, Schöttker, Ben, Hoffmeister, Michael, Brenner, Hermann
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.07.2018; MDPI
• Subjects: 25-Hydroxyvitamin D; Blood; Clinical trials; Cohort analysis; cohort studies; Colorectal cancer; Colorectal carcinoma; Confidence intervals; dose-response; Dose-response effects; Heterogeneity; Medical prognosis; Meta-analysis; mortality; Patients; Review; Subgroups; Survival; Systematic review; Upgrading; Vitamin D; cohort studies; dose-response; meta-analysis; mortality; colorectal cancer; vitamin D
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu10070896

Previous meta-analyses have shown an improved survival with higher blood 25-hydroxyvitamin D (25(OH)D) concentrations in patients with colorectal cancer (CRC). However, a number of much larger studies have been published since then. We provide an updated meta-analysis to synthesize current evidence. PubMed and Web of Science databases were systematically searched for eligible studies. The dose-response relationships and pooled hazard ratios for overall and CRC-specific survival comparing the highest versus the lowest categories of blood 25(OH)D concentrations were assessed. Subgroup analyses based on study geographic location, year of publication, sample size, length of follow-up time and stage were conducted to explore potential sources of heterogeneity. Overall, 11 original studies with a total of 7718 CRC patients were included. The dose-response meta-analysis showed an improvement in survival outcomes with increasing blood 25(OH)D concentrations. Pooled hazard ratios (95% confidence intervals) comparing highest versus lowest categories were 0.68 (0.55⁻0.85) and 0.67 (0.57⁻0.78) for overall and CRC-specific survival, respectively. Associations were more prominent among studies conducted in Europe, with larger sample sizes, and including stage I⁻IV patients. This updated meta-analysis reveals robust evidence of an association between higher blood 25(OH)D concentrations and better survival in CRC patients. The potential for enhancing prognosis of CRC patients by vitamin D supplementation should be explored by randomized trials.