CNS Involvement in Childhood and Adolescence Non-Hodgkin Lymphoma: Prevalence and Patient’s Outcome Differ According to the Subtype.
Authors: Salzburg Janina , Burkhardt Birgit , Wachowski Olga , Zimmermann Martin , Parwaresch Reza , Ludwig Wolf-Dieter , Mann Georg , Niggli Felix , Riehm Hansjörg , Schrappe Martin , Reiter Alfred 
Published: April 2020

Abstract
We evaluated the prevalence and clinical significance of CNS involvement in childhood and adolescence Non-Hodgkin Lymphoma (NHL).
Between 10/86 and 12/02, 2,086 eligible patients (pts) were registered in the subsequent multicenter trials NHL-BFM86, −90, −95. Median follow up was 6.5 years (0.3–17.7 years). Initial staging included examination of cerebrospinal fluid (CSF) and cranial CT or MRI. CNS involvement was diagnosed in case of CSF blasts, and/or intracerebral mass (ICM), and/or cranial nerve palsy (CNP), not caused by an extradural mass. Epidural NHL without any of the above criteria was not considered as CNS disease. CNS positive (pos) pts with lymphoblastic lymphoma (LBL) received an 8-drug induction, consolidation, re-intensification, and maintenance up to 2 years. CNS therapy included dexamethason, methotrexate (MTX) 5 g/m2 i.v., 13 dosis of intrathecal (i.th.) MTX, and cranial radiotherapy (CRT). CNS pos pts with non-LBL received six 5-day courses based upon vincristine, vindesine, dexamethason, oxazophorins, cytarabine, etoposide, doxorubicin, MTX 5 g/m2 i.v., and intraventricularely or i.th. applied chemotherapy. CRT was omitted since study BFM90, except for pts with anaplastic large cell lymphoma (ALCL). 111 of the 2,086 analyzed NHL pts were initially diagnosed as CNS pos. 1,933 pts were CNS negative (neg) and in 42 pts the CNS status was questionable or not evaluable due to incomplete diagnostics. Prevalence and outcome of CNS pos pts according to NHL subtypes were as follows.
In the total group, the probability of event free survival at 5 years (pEFS) was 63 ± 5% for CNS pos pts compared to 81 ± 1% for CNS neg pts with stage III/IV NHL (n=1,323) (p&lt; 0.0001). In LBL pts pEFS was 81 ± 10% for CNS pos pts and 84 ± 2% for CNS neg pts with stage III/IV (n=359) (p=0.54), while in Burkitt/B-ALL pEFS was 60 ± 5 % for CNS pos pts versus 85 ± 1% for CNS neg pts with stage III/IV (n=599) (p&lt;0.0001). For CNS pos Burkitt/B-ALL pts pEFS was 57 ± 7% for 57 pts with and was 67 ± 10% for 24 pts without bone marrow involvement (p=0.31).
Total LBL (T-, pB-) Burkitt/B-ALL PMLBL* DLBL° ALCL Others *primary mediastinal large B-cell lymphoma, °diffuse large B-cell lymphoma Number of pts 2086 433 1003 40 222 215 173 CNS pos pts 111 16 81 0 4 5 5 Percentage 5,3% 3,7% 8,1% 0 1,8% 2,3% 2,9% Chracteristics and outcome of CNS pos pts CSF blasts +/ − others 81 13 60 0 1 4 3 ICM (without CSF blasts) 18 2 11 0 2 1 2 CNP 12 1 10 0 1 0 0 Death unrelated to tumor 6 0 6 0 0 0 0 Relapse/Nonresponse 30 2 24 0 0 2 2 CNS involved 18 1 15 0 0 2 0
In summary, CNS-disease was most frequent in pts with Burkitt/B-ALL, while it was rare in DLBL pts. In Burkitt/B-ALL, CNS pos pts had a worse outcome compared to CNS neg pts with advanced stage disease, while in LBL pts outcome was comparable for CNS pos and CNS neg pts.