Central Nervous System Relapse in Patients with Peripheral T-Cell Lymphoma
Authors: Jeong Hyehyun , Hong Jung Yong , Yoon Dok Hyun , Kim Shin , Park Jung Sun , Lee Sang Wook , Park Chan Sik , Ryu Jin-Sook , Huh Jooryung , Suh Cheolwon 
Published: October 2019

Abstract
Introduction: Central nervous system (CNS) relapse or progression in peripheral T-cell lymphoma (PTCL) is a rare event. Due to its rarity, little is known about the incidence, risk factors and the clinical course after CNS relapse in PTCL.
Methods: A total of 301 patients with PTCL were included in this study. All patients were diagnosed between 2003.1 and 2016.6 in Asan Medical Center, Seoul, Korea. Patients with CNS involvement at diagnosis and cutaneous anaplastic large-cell lymphoma were excluded.
Histologic subtypes included peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS) (n=151, 50.2%), anaplastic large-cell lymphoma (ALCL) (n=75, 24.9%, including ALK positive/negative/unknown, n=39/33/3 each), angioimmunoblastic T-cell lymphoma (AITL) (n=54, 17.9%), enteropathy-associated T-cell lymphoma (EATL) (n=21, 7%).
Disease progression or relapse with CNS involvement was confirmed by pathology or MRI of the affected organ. Risk factors at diagnosis for subsequent CNS progression were analyzed with cox regression method. P value <.05 was considered as statistically significant.
Results: Out of 301 patients enrolled, 197 patients were male and 104 patients were female. Median age at diagnosis was 57 (range: 15-86). During 75.1 months of median follow-up, 10 patients developed CNS relapse or progression (3.3%).
Among those 10 patients with CNS involvement, 4 patients had PTCL-NOS, 4 patients had ALCL (3 ALK positive, 1 ALK negative) and 2 patients had EATL. Leptomeningeal involvement of lymphoma was found in 6 out of 10 patients. Brain or spinal parenchymal involvement was found in 1 patient. Three patients had both leptomeningeal and parenchymal involvement.
Median time from initial diagnosis to CNS involvement was 3.6 months (95% confidence interval (CI): 1.1-6.2). All patients with CNS relapse or progression died, and their median overall survival (OS) from CNS involvement was 1.4 months (0.2-2.6). Median OS from diagnosis was 5.1 months (2.9-7.3) in these patients. On the other hand, median OS of patients without CNS relapse was 10.3 months (7.8-12.9) (p=0.002).
Univariate analysis showed 2 risk factors associated with occurrence of CNS relapse or progression as follows; subcutaneous tissue or muscle involvement (hazard ratio (HR) 8.9 [95% CI: 2.5-31.5], p=0.001) and Ki-67 labeling index≥80% (HR 11.9 [1.5-94.8], p=0.02). Due to the small number of CNS events, multivariate analysis was not available. No association was found with age, sex, international prognostic index, histologic type, serum lactate dehydrogenase level, stage of the disease and number of involved extranodal sites.
Conclusions: Our study demonstrated that although CNS relapse or progression in PTCL was rare (3.3%), it showed dismal prognosis with median OS of 1.4 months. Since CNS involvement occurred in the early course of the disease, we suggest that evaluation for CNS disease should be considered in highly selected patients.
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Disclosures
No relevant conflicts of interest to declare.