BACKGROUND: Vitamin D deficiency and inflammation are associated with increased mortality. We investigated the relationship between pre-treatment serum vitamin D levels, inflammatory biomarkers (IL-6, YKL-40 and CRP) and overall survival (OS) in pancreatic ductal adenocarcinoma (PDAC) patients.
METHODS: Pre-treatment serum vitamin D, IL-6, YKL-40 and CRP levels were determined in 1,267 patients with PDAC enrolled from July 2008 to September 2018 in the prospective BIOPAC study (NCT03311776). The patients were grouped according to vitamin D levels: sufficient >50 nmol/L, insufficient 25-50 nmol/L and deficient <25 nmol/L.
RESULTS: Across all tumour stages, vitamin D-deficient patients had the highest median levels of IL-6 (8.3 pg/mL, range 0.7-91), YKL-40 (177 ng/ml, range 25-5279) and CRP (15.5 mg/L, range 0.8-384). The resected stage I and II patients with vitamin D deficiencies had a shorter median OS, 18.3 months (95% CI, 12.1-31.5 months) than those with sufficient levels, 29.7 months (95% CI, 22.3-36.1 months), and the hazard ratio for death was 1.55 (95% CI, 1.04-2.31; p = 0.03). In advanced PDAC, there was no significant difference in OS between the vitamin D groups.
CONCLUSIONS: Vitamin D deficiency was associated with increased inflammatory biomarkers in all PDAC stages. The resected stage I and II patients with sufficient vitamin D levels had a higher OS than those with a vitamin D deficiency. However, there was no correlation between vitamin D levels and survival in advanced PDAC. Future studies need to investigate vitamin D supplementation effects on survival in PDAC.