PD-L1 (SP142) expression in neoplastic cells predicts a poor prognosis for patients with intravascular large B-cell lymphoma treated with rituximab-based multi-agent chemotherapy.

Yuka Suzuki,Shigeo Nakamura,Ayako Sakakibara,Taishi Takahara,Seiichi Kato,Eri Ishikawa,Satoko Shimada,Kei Kohno,Kazuyuki Shimada,Akira Satou,Seiyo Mabuchi,Kosei Matsue

doi:10.1002/cam4.3104

Abstract

BackgroundIntravascular large B‐cell lymphoma (IVLBCL) is a rare form of diffuse large B‐cell lymphoma (DLBCL) arising in extranodal sites. PD‐L1 expression of tumor cells has been reported in IVLBCL cells, but its clinicopathological relevance remains to be elucidated.AimsThis study was aimed to reveal the characteristics of PD‐L1+ IVLBCL.Methods and resultsNeoplastic PD‐L1 expression was examined in 34 cases of IVLBCL and clinicopathological characteristics between patients with PD‐L1+ and PD‐L1− IVLBCL were compared. We assessed PD‐L1 expression with SP142 antibody. Twelve (35%) of 34 cases showed positivity for PD‐L1. The PD‐L1+ group had significantly lower survival rates compared to the PD‐L1− group. The PD‐L1+ IVLBCL group also had a significantly lower age distribution and a lower frequency of patients older than 60 years compared to the PD‐L1− group. Very recently, we speculate that there is possible link between PD‐L1+ IVLBCL and PD‐L1+ extranodal DLBCL‐NOS (eDLBCL) because features of the two groups showed overlapping. Therefore, we compared the clinicopathological characteristics of the PD‐L1+ IVLBCL and PD‐L1+ eDLBCL. There were no significant differences in clinicopathological parameters and prognosis.ConclusionThe worse prognosis of the PD‐L1+ group might be caused by immune evasion mechanisms, which are linked to PD‐L1 expression. Therefore, PD‐L1+ IVLBCL cases might be regarded as good candidates for targeted immunotherapy. We also highlighted the overlapping features of PD‐L1+ IVLBCL and PD‐L1+ eDLBCL. This result suggests that they should be regarded as one entity, immune evasion‐related extranodal large B‐cell lymphoma.

Highlights

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of diffuse large B-cell lymphoma (DLBCL) arising in extranodal sites
Studies have indicated that neoplastic Programmed death-ligand 1 (PD-L1) expression is a promising poor prognostic indicator, because it is often associated with adverse clinicopathological parameters in patients.[17,18,30-36]
Few reports have focused on this issue in IVLBCL, and those were case reports on a single patient or a short series.[17,25-27,37]

Summary

| INTRODUCTION

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of diffuse large B-cell lymphoma (DLBCL) arising in extranodal sites. PD-L1 expression of tumor cells has been reported in IVLBCL.[17]. Gupta et al investigated PD-L1 expression in 11 cases of IVLBCL, and they evaluated the correlation between PD-L1 expression and clinical and pathological features.[25]. That series showed that most clinical and pathological features were not significantly different between patients with PD-L1+ and PD-L1− tumor cells. We suggested that PD-L1+ IVLBCL and PD-L1+ eDLBCL might be categorized into one proposed entity, immune evasion-related extranodal large B-cell lymphoma. The clinicopathological relevance of neoplastic PD-L1 expression remains to be elucidated among patients with IVLBCL because the number of reported cases is limited. Neoplastic PD-L1 expression in 34 cases of IVLBCL was investigated and the clinicopathological characteristics between patients with and without PD-L1 positivity were compared

| MATERIAL AND METHODS

| RESULTS

Findings

| DISCUSSION