25(OH) vitamin D deficiency in lymphoid malignancies, its prevalence and significance. Are we fully aware of it?

INTRODUCTION: Vitamin D has a role in cellular differentiation, proliferation, apoptosis, and angiogenesis and therefore is studied as a prognostic factor in cancer. The aim of our study was to assess the prevalence and significance of 25(OH)D deficiency in patients with lymphoid malignancies. METHODOLOGY: Between January 2014 and June 2016 at the Clinic for Hematology, Clinical Center of Serbia, Belgrade, the pretreatment serum level of 25(OH)D was determined in 133 (62 women/71 men, median age 58 (18-84) years) previously untreated patients with lymphoid malignancy using a chemiluminescent immunoassay. From their medical records, we noted the age, clinical stage, Eastern Cooperative Oncology Group Performance Scale (ECOG PS), nutritional status using the Nutritional Risk Score 2002 (NRS2002), the time of year, comorbidity index, progression, and progression-free survival (PFS) for a median of 20 (1-32) months. The optimal cutoff point for prediction of outcome was determined using the Maximally Selected Rank Statistics. RESULTS: There were 37 (27.8%) patients with the severe 25(OH)D deficiency ≤ 25 nmol/l, 80 (60.2%) with 25(OH)D deficiency 25-50 nmol/l, and 16 (12%) with 25(OH)D insufficiency 50-75 nmol/l. None of the patients had the desired normal level. There were significant differences between groups in regard to ECOG PS, NRS2002, type of lymphoma, and progression. The severely 25(OH)D-deficient patients had a shorter mean time until progression (P = 0.018). Cox regression analysis showed that 25(OH)D < 19.6 nmol/l remained the only significant parameter for PFS (HR = 2.921; 95% CI 1.307-6.529). CONCLUSION: The prevalence of 25(OH)D deficiency in the analyzed group of patients with lymphoid malignancies is high and greater in malnourished individuals. Patients with pretreatment serum 25(OH)D < 19.6 nmol/l had a significantly shorter PFS.