Low grade b-cell non-Hodgkin lymphomas (NHL) involving the central nervous system (CNS): An analysis from the National Cancer Database (NCDB).

Abstract

e13083 Background: CNS involvement from low grade B-cell NHL is rare and has only been reported as case series. The distribution, demographics and outcomes of patients with low grade B-cell CNS NHLs have not been well characterized. Methods: The NCDB represents ~70% of cancer cases in the United States. Using the 2004-2013 NCDB extranodal NHL database, we identified all CNS B-cell NHLs based on ICD-O-3 site and histology codes. Primary or secondary CNS involvement could not be determined. Results: Out of 9435 CNS NHL cases, 475 [5.03%] had low grade histologies. In this group, the median age at diagnosis was 58 years [range 19-89]. Majority of the cases were female [56%], White, non-Hispanic [72%], privately insured [53%], with no comorbidities [74%] and treated in academic/research programs [38%]. Site of CNS disease was not specified in 22%. HIV status was known in 318 cases (6.3% positive). The brain [44%] was the most common site of involvement followed by spinal cord [19%] and meninges [15%]. Follicular lymphoma (FL) [48%] was the most common histology overall followed by marginal zone (MZL) [37%], small lymphocytic (SLL) [8%] and lymphoplasmacytic lymphomas (LPL) [7%]. MZL was the most common histology in the brain [44%] and meninges [61%] while FL was most common in the spinal cord [77%] and nervous system, NOS [69%]. Cranial nerves and eye (retina/optic nerve) involvement was very rare [2 and 1 case each- both MZL]. The overall survival (OS) of CNS B-cell NHL was significantly better if histology was low grade vs other [5-year OS 74% vs 32%, P < 0.0001]. Among CNS low grade B-cell NHLs, 5-year OS varied by histology [MZL 83%, FL 75%, LPL 56% and SLL 50%, P = 0.0003] and site of disease [spinal cord 89%, meninges 78% and brain 63%, P = 0.03] in addition to age at diagnosis and co-morbidities on both uni- and multivariate analysis. Survival was not influenced by sex, race, insurance, year of diagnosis, facility type or location. Conclusions: CNS involvement with low grade B-cell NHL is rare but has a relatively good outcome with most patients surviving beyond 5 years. FL and MZL are the more common low grade histologies. Both histology and disease site are important factors affecting survival.