The prognostic value of 25-hydroxy vitamin D deficiency and its interaction with c-Myc expression in diffuse large B cell lymphoma

This study investigated the prognostic value of 25-hydroxy vitamin D (25-(OH)D) deficiency and the association between 25-(OH)D deficiency and c-Myc positivity in 208 newly diagnosed diffuse large B cell lymphoma (DLBCL) patients. 25-(OH)D deficiency was defined as serum 25-(OH)D level lower than 52.5 nmol/L. Using cutoff values of 40%, positive tumor cells for c-Myc expression was established. One hundred forty-two patients had 25-(OH)D deficiency and 70 had c-Myc positivity with a median follow-up of 29 months (range, 16 to 49 months) in this cohort. Multivariate Cox regression analysis showed that 25-(OH)D deficiency was an independent prognostic predictor for inferior progression-free survival (PFS) (P = 0.001) and overall survival (OS) (P = 0.006), and c-Myc positivity was an unfavorable prognostic factor for PFS (P = 0.004). In addition, c-Myc positivity was more frequent in patients with 25-(OH)D deficiency (P = 0.027). Moreover, we found that the presence of c-Myc positivity could aggravate the adverse effects of 25-(OH)D deficiency for PFS time (P = 0.0045). 25-(OH)D deficiency together with IPI (IPI-D) improved the prognostic capacity compared with only IPI in predicting the risk of DLBCL which was assessed by the calculation of receiver operator characteristic (ROC) curves and the areas under the curve (AUC). Noteworthy, c-Myc positivity combined with IPI-D was better than IPI-D in predicting PFS time. In summary, 25-(OH)D deficiency was a strong prognostic factor in DLBCL. Further multi-center prospective studies are needed to confirm the results and better understand the underlying mechanisms.