Histological vascular invasion is a novel prognostic indicator in extranodal natural killer/T-cell lymphoma, nasal type.

Extranodal natural killer (NK)/T-cell lymphoma, (ENKTL), nasal type, is an aggressive lymphoma with no validated prognostic parameters, to date. In the present study, vascular invasion by this tumor was retrospectively analyzed in 214 patients with untreated ENKTL to evaluate its association with clinical features, treatment response and prognosis. Histological vascular invasion by the tumor was confirmed in 32.7% of patients with ENKTL. The presence of vascular invasion significantly correlated with poor performance status, B symptoms, extranodal involved sites, advanced stage, elevated serum lactate dehydrogenase, D-dimer and cluster of differentiation 68(+) tumor-associated macrophages. Upon treatment termination, the complete remission (CR) rate and overall response rate were significantly lower for the vascular invasion group compared with the non-vascular invasion group. Furthermore, vascular invasion resulted in significantly reduced 5-year progression-free survival (PFS; 21.8 vs. 60.1%) and overall survival (OS; 36.8 vs. 77.0%) rates. Using the multivariate Cox regression model, vascular invasion, stage III/IV and CR after chemotherapy were independent prognostic factors for OS and PFS. Thus, histological vascular invasion by the tumor affected the response to treatment, and was also an independent prognostic factor for OS and PFS in ENKTL, nasal type, suggesting a role for vascular invasion in disease progression.