Thanarajasingam, Gita

6511 Background: Conventional adverse event (AE) analysis (ToxC) focuses on incidence of grade (gr) 3+ toxicities, and fails to capture AE time profile. Novel metrics that reflect chronic low gr and overall AE burden are needed. We applied the Toxicity over Time (ToxT) approach to ECOG-ACRIN 2408 to depict time-dependent toxicity of lenalidomide (L) with rituximab maintenance (MR) in follicular lymphoma (FL), and we developed a novel summary metric of symptomatic AE burden, the maximum gr over time (MGOT). Methods: In E2408, high risk FL patients (pts) were randomized (1:2:2) to: A) bendamustine-rituxumab (BR) x 6 then MR x 2 years (yrs) vs B) BR-bortezomib x 6 then MR x 2 yrs vs C) BR x 6 then MR x 2 yrs + L x 1 yr (MRL). Analysis included 3 laboratory and 5 symptomatic AEs of highest incidence during maintenance on arms A and C. Treatment-related AEs of any gr were analyzed by ToxC and ToxT. Repeated measures, time-to-event (TTE) and area under the curve (AUC) analyses capture trends over time in ToxT. MGOT combines the 5 symptomatic AEs. Results: 104 randomized pts (30 MR, 74 MRL) were included. For the laboratory AEs, by ToxC, neutropenia incidence was significantly higher in MRL (84%) than MR (47%, p < .001). ToxT additionally shows neutropenia does not worsen over time (10/14/20% gr 1/2/3+ at c1, 6/21/12% gr 1/2/3+ at c12). For the symptomatic AEs, ToxC indicates 2% gr 3+ GI AEs. However, gr 1-2 GI AEs are more common on MRL (59%) than MR (26%, p < .001). ToxT AUC captures a higher burden of GI AEs over time on MRL(2.8) vs MR(1.4, p = .002). TTE depicts sooner GI AE onset in MRL (10% vs 0% gr 2+ GI by day 50, p = 0.03). Bar charts of incidence and grade by cycle illustrate this improves over time (34/7/4% gr 1/2/3+ at c1, 13/0/0% gr 1/2/3+ at c12). ToxT MGOT analyses demonstrate earlier time to gr 2+ symptomatic AE on MRL vs MR (63% vs 31% by day 50, p < .001) and suggest that overall AE burden over time is higher for patients on MRL(AUC 18.2) than MR(11.8, p < .001). Conclusions: ToxT depicts AE time profile and can guide AE interventions. Summary metrics suggest that symptomatic AEs occur earlier and their burden over time is higher on MRL. We are implementing ToxT in patient-reported AE data to better characterize pt tolerability.

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.

ObjectivesPrimary skull base lymphoma (PSBL) represents a rare manifestation of extranodal lymphoma. Presenting with nonspecific symptomatology and imaging findings, PSBL often masquerades as more common cranial base pathology and thus can present a diagnostic challenge. The objectives of this study were to characterize the manifestations and clinical outcomes of PSBL.Study DesignCase series and chart review.SettingTertiary referral center.Subjects and MethodsReview of 48 patients with PSBL treated between 1994 and 2016.ResultsThe median age at diagnosis was 60 years. Diffuse large B‐cell lymphoma comprised the most common subtype (56%). Presenting symptoms included diplopia (52%), trigeminal hypesthesia (38%), headache (29%), facial nerve weakness (25%), B‐symptoms (fevers, night sweats, and/or weight loss) (25%), and hearing loss (21%). Discrete lesions commonly mimicked meningioma, schwannoma, and nasopharyngeal carcinoma. Diffuse lesions imitated neurosarcoidosis, granulomatosis with polyangiitis, and carcinomatosis meningitis. Only 26% of all initial clinical evaluations suspected lymphoma. The combination of restricted diffusion on diffusion‐weighted imaging, an absence of flow voids or surrounding hyperostosis, bony erosion and/or marrow signal replacement, and heterogeneous contrast enhancement facilitated delineation between PSBL and common skull base pathology. Cerebrospinal fluid (CSF) analysis was diagnostic of lymphoma in 24% of cases. Lymphoma within CSF portended significantly worse overall survival (85% vs 18% at 3‐years; P <. 001).ConclusionA history significant for multiple cranial nerve palsies, B‐symptoms, and imaging findings inconsistent with common skull base pathology should raise suspicion for PSBL. CSF analysis in the setting of PSBL can provide diagnostic and prognostic value for patients.

Summary This study aimed to describe the patterns of care and outcomes of diffuse large B cell lymphoma ( DLBCL ) after failure of front line anthracycline‐based immunochemotherapy ( IC ). Patients with newly diagnosed lymphoma were prospectively enrolled in Molecular Epidemiology Resource ( MER ) of the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellzence. All DLBCL and primary mediastinal B‐cell lymphoma ( PMBL ) patients treated with front‐line anthracycline‐based IC were followed for relapse. Patients with relapse on follow‐up and subsequently retreated were included in this analysis. 1039 patients received anthracycline‐based IC between 2002 and 2012, of which 244 relapsed and were subsequently retreated. Across all therapies, overall survival at 4 years ( OS 4) from relapse was 28% and 103 patients ultimately underwent autologous haematopoietic cell transplant (auto HCT ) with OS 4 from auto HCT of 51%. Patients relapsing after 12 months from initial diagnosis had OS 4 of 47% but those with a transient or no response to initial therapy had OS 4 of only 13%. Outcomes of relapsed or refractory DLBCL differ substantially when categorized by response to initial therapy, timing of relapse and opportunity to undergo auto HCT . The design and interpretation of uncontrolled trials should account for this heterogeneity in patients with relapsed DLBCL .