['To determine whether serum vascular endothelial growth factor (s-VEGF) levels and VEGF gene expression in tumor tissue predict survival of diffuse large B-cell lymphoma (DLBCL) patients treated with chemoimmunotherapy.', 'VEGF levels were measured in serum samples from 102 patients <65 yrs with high-risk DLBCL using a quantitative sandwich enzyme immunoassay technique. Exon array data set of tumor tissues from 32 patients was concurrently used to determine VEGF-A exon and gene expression. All patients were treated in a Nordic phase II study with six dose-dense chemoimmunotherapy courses followed by systemic central nervous system prophylaxis.', 'After a median follow-up time of 40 months, 3-yr progression-free survival (PFS) was inferior in patients with high s-VEGF levels compared to those with low levels (59% vs. 83%, P = 0.005). The relative risk of progression or relapse was 3.1-fold (95% confidence interval 1.34-6.91, P = 0.008). The predictive capacity of s-VEGF levels on PFS was most pronounced in the DLBCLs of non-germinal center subtype. In contrast to serum data, VEGF mRNA expression in the lymphoma tissue did not predict outcome, and no correlation was found between s-VEGF levels and lymphoma VEGF expression.'] Is high serum vascular endothelial growth factor level an adverse prognostic factor for high-risk diffuse large B-cell lymphoma patients treated with dose-dense chemoimmunotherapy?