McPhail, Ellen Darcy

The transthyretin (TTR) and immunoglobulin light chain proteins do not exist in isolation in cardiac amyloid (CA) plaques. Laser microdissection followed by mass spectrometry-based proteomic (LMD-MS) typing techniques can identify hundreds of co-deposited proteins in the "nano-environment" of amyloid deposits. Some, such as the "amyloid signature" proteins (SAP, APOE, APOA4, vitronectin, clusterin), are specific for amyloid plaques across different tissues and amyloid types. However, many of the remaining proteins are also abundant in the serum or normal tissues making it difficult to discern if they are unique to the amyloid plaque or part of the normal tissue background. We included 288 patients/samples with TTR CA (of which 53 were mutated) diagnosed by endomyocardial biopsy and 5 normal control samples obtained from 3 patients during autopsy. At the time of the meeting updated analyses including 168 cardiac light chain amyloid patients and 15 controls from patients with restrictive and hypertensive cardiomyopathy will be presented. Normalized spectral counts were used as a semi-quantitative measure of abundance. Proteins were considered part of the proteome if their abundance in the amyloid plaque was increased by 1.5-fold compared to normal controls (FDR p<0.05). Of 2240 unique proteins identified across all samples, 42 were differentially expressed in amyloid plaques. These included a) signature proteins: SAP, APOE, APOA4, vitronectin, clusterin; b) serum proteins: albumin, b2-glycoprotein, 7 complement pathway proteins; c) matrix proteins: 2 collagen isoforms, fibulin 1, decorin, PCOLCE2, TIMP3; d) cytosketal and contractile proteins: 2 actin isoforms, MYL2, 8 myosin isoforms, 3 ankyrin isofroms, desmin; and "other" proteins: serpine2, MAGE-like protein-2, pleiotrophin, AMBP, SRPX and QSOX1). The signature and cytoskeletal proteins were the most abundant overall, however, proteins that were most increased compared to normal included (log2 fold change in parentheses): fibulin (24.5), PCOLCE2 (23.5), b2-glycoprotein (23.5), factor H related peptide-2 (24.2), serpine2 (24.7), mage-like protein-2 (22.8), pleiotrophin (23.8), QSOX1 (22.9), SRPX (23.5). B2 glycoprotein was more abundant in wild type TTR samples(p=0.003). APOE (p=0.002), fibulin (p=0.008) and serpine2 (p<0.0001) were more abundant in UK stage (Gilmore JD et al, Eur Heart J 2018) 2/3 patients. Unsupervised hierarchical clustering of patients by normalized protein abundance revealed two major distinct patterns of co-deposited proteins (figure). Patients with high levels of contractility proteins (myosin isoforms, desmin, actins) were characterized by low levels of most other proteins (clusters on the left). Most complement proteins co-deposited along with higher levels of signature proteins (clusters on the right). When comparing clinical and laboratory characteristics between those 2 groups of patients only cardiac strain was found to be significantly higher (worse) in patients with lower levels of contractility proteins (p=0.01). Our data shows that the TTR CA proteome includes signature, serum and cardiac tissue proteins with variable expression according to TTR mutation status and cardiac functional status, which could inform mechanisms of disease pathogenesis. Comparison with diseased controls may further clarify if this proteomic pattern is specific to CA. Figure Disclosures Dasari: The Binding Site: Patents & Royalties: US Patent Rights on Mass Spectroscopy Licensing agreement with The Binding Site, Research Funding. Dispenzieri:Akcea: Consultancy; Intellia: Consultancy; Janssen: Consultancy; Pfizer: Research Funding; Takeda: Research Funding; Celgene: Research Funding; Alnylam: Research Funding.

Abstract MYC amplification (amp) is a marker of poor prognosis in many non-hematologic malignancies. While MYC translocations in B cell lymphoma (BCL) have been extensively studied, little is known about the significance of MYC amp. Recent studies describe increased MYC copy numbers (3-10 copies/cell) to be associated with more aggressive BCL. The WHO 2017 does not include MYC amp in the definition of high-grade BCL (HGBCL) with MYC and BCL2 and/or BCL6 rearrangement ("double-hit lymphoma", DHL). However, it also states that high-level MYC amp occurring together with a MYC rearrangement, and concurrent with BCL2 rearrangement likely has a similar clinical impact as classic DHL. Although increased MYC copy number is commonly identified by routine fluorescence in situ hybridization (FISH) testing in BCL, the experience of our large cytogenetics reference laboratory suggests that high-level MYC amp, defined as uncountable MYC signals, is far less common. Therefore, we sought to characterize the clinical, pathologic and cytogenetic features of patients with BCL showing high-level MYC amp. The Mayo Clinic cytogenetic database was retrospectively reviewed for all cases of BCL with high-level MYC amp seen by FISH from January 2010 - February 2018. All FISH studies reported as MYC amp were re-reviewed by a cytogeneticist to verify the level of amp and the MYC probes involved. Pathology was reviewed by two independent hematopathologists. Clinical information was collected through chart review. Survival analysis was performed using Kaplan-Meier curves and the Wilcoxon rank-sum test. FISH analysis for MYC aberrations identified 44/9715 (0.45%) cases with high-level MYC amp. Of cases with available H&E, the most common morphology was diffuse large BCL (DLBCL) (82%; 28/34), followed by HGBCL (15%; 5/34) and plasmablastic BCL (3%; 1/34). Hans cell of origin (COO) algorithm immunohistochemistry (IHC) identified 21/25 (84%) germinal center B-cell-like (GCB), and 4/25 (16%) non-GCB cases. 21/27 (78%) cases were BCL2+ by IHC. MYC+ by IHC was ≥40% in 21/28 (75%) and <40% in 7/28 (25%) cases. 9/17 (53%) were "double expressers" (DEL) by IHC. MYC amp probe signals appeared in a cloud-like distribution (CLD) in 31 (70%) or in a single homogenous staining region (HSR) in 13 (30%) [Figure 1A]. Among 38 cases with amp in a MYC break-apart probe, 21 (55%) had amp of 5' alone, 15 (40%) of intact and 2 (5%) of the 3' probe alone. 7/44 (16%) had MYC translocations (5 IGH; 2 non-IGH). BCL2 rearrangement was seen in 15/39 (38%) cases, and BCL6 rearrangement in 3/36 (8%). Only 2/44 (4%) cases met the current WHO 2017 definition of DHL. Clinical data was available for 20 cases. Median age at diagnosis was 64.5 (range 25-88) years with M:F of 1.5:1. Only 1/14 (7%) had bone marrow while 16/18 (88.8%) had other extranodal sites of involvement (8 gastrointestinal). The clinical presentation was heterogeneous: 13 de novo, 3 post-transplant, 3 transformed from low grade and 1 mediastinal BCL. 9/14 had an elevated LDH, median 387 (225 - 2063) U/L. R-CHOP was the most common first line therapy in 12/17 (70%). At median follow-up of 18.2 (range 0.4 - 88.9) months, 9 patients had died, 3 were in relapse and 8 remained in first complete remission. Lymphoma relapse/progression was the most common cause of death in 7/9 (78%). The median overall survival (OS) was 29.3 months [Figure 1B]. There was no statistically significant difference in OS by morphologic classification (DLBCL vs HGBCL, p=0.6), double expresser (Yes/No, p=0.19), COO (GCB vs non-GCB, p=0.08), MYC amp pattern (HSR vs CLD, p=0.48), MYC amp probe (3' vs 5' vs intact, p=0.31), MYC rearrangement (Yes/No, p=0.1), or MYC amp with concurrent BCL2/BCL6 rearrangement (Yes/No ,p=0.2). To our knowledge, this is the first study to characterize the clinical, pathologic and cytogenetic features of BCL with strictly-defined high level MYC amp identified by FISH. The 5' signal alone, or the intact MYC probe are most frequently amplified, and two distinct patterns of amp can be seen. Predominant extra nodal involvement is an important clinical observation. These cases are usually DLBCL, GCB type, and infrequently have concurrent MYC/BCL2/BCL6 rearrangement. Our study suggests that BCL with high-level MYC amp may have an aggressive disease course regardless of MYC, BCL2 and BCL6 gene rearrangement status. A larger series is necessary to further understand the clinical significance of high-level MYC amp in BCL. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract ATTRwt (formerly known as senile) amyloidosis and plasma cell disorders share a common demographic of occurrence with increasing prevalence with age. We aimed to identify the prevalence of plasma cell disorders in patients diagnosed with ATTRwt. We retrospectively reviewed all patients seen at Mayo Clinic Rochester between 1st January 2009 and 31st of December 2017 who were diagnosed with ATTRwt. The start date of the study was chosen to coincide with routine clinical availability of laser microdissection mass spectrometry (LCMS) for subtyping of amyloidosis. 492 patients with ATTRwt were evaluated during the study period. Serum immunofixation electrophoresis (SIFE), urine immunofixation electrophoresis (UIFE) and serum free light chain (FLC) assay testing was performed in 74% (n=362), 53% (n=261) and 79% (n=386) respectively. Of the 492 ATTRwt seen during this period, 139 (28%) had abnormal monoclonal protein studies, the vast majority (92%, n=128) of which were monoclonal gammopathy of undetermined significance (MGUS). Monoclonal protein testing in this cohort included SIFE, UIFE and FLC in 96% (n=134), 71% (n=99) and 99% (n=137) respectively. The non-MGUS diagnoses included smoldering multiple myeloma in <1%% (n=2), multiple myeloma (MM) in 6% (n=8), AL amyloidosis in 2% (n=3), and lymphoplasmacytic lymphoma (LPL) in 3% (n=4). MM and LPL developed after progression from MGUS in 2 and 3 patients respectively. Two patients with MGUS also had a diagnosis of low grade non Hodgkin lymphoma (chronic lymphocytic leukemia in one and marginal zone lymphoma in the other). The abnormal monoclonal protein studies included SIFE in 55%, UIFE in 26% and an abnormal serum free light chain ratio (FLCr) in 73%. The organ biopsied for the diagnosis of ATTRwt was heart in 43% (n=60), bone marrow in 24% (n=33), fat in 9% (n=12) and other sites in 5% (n=8, 3 lung, 2 lip, 2 bladder and 1 small bowel). LCMS confirmed the subtype of amyloidosis as ATTRwt in all patients with a biopsy positive for amyloidosis by congo red staining. 19% (n=26) of patients were diagnosed with ATTRwt based on clinical features and a strongly positive PYP scan. PYP scan was positive for ATTR in 55/56 patients in whom the test was performed. The most common monoclonal protein isotypes detected were light chain (45%) and IgG (28%). Light chain subtype was kappa in the majority of patients (80%). Plasma cell disorders are not uncommon in patients with ATTRwt amyloidosis. The diagnosis of a plasma cell disorder and ATTRwt are not mutually exclusive, and their coexistence can confuse the diagnosis if amyloid typing is not performed. Patients with ATTRwt may be misclassified as AL amyloidosis due to the presence of amyloid and a clonal plasma cell disorder with significant prognostic and therapeutic implications. Disclosures Kumar: Novartis: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding. Lacy:Celgene: Research Funding. Dingli:Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Gertz:Ionis: Honoraria; Research to Practice: Consultancy; Amgen: Consultancy; Prothena: Honoraria; Alnylam: Honoraria; Medscape: Consultancy; celgene: Consultancy; Teva: Consultancy; Abbvie: Consultancy; janssen: Consultancy; spectrum: Consultancy, Honoraria; annexon: Consultancy; Apellis: Consultancy; Physicians Education Resource: Consultancy. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding.

Abstract Primary central nervous system lymphoma (PCNSL) is an aggressive and incurable variant of non-Hodgkin lymphoma (NHL) that is confined to the central nervous system. Most PCNSL (90%) are part of the immune-privileged site-associated diffuse large B-cell lymphomas (DLBCL). Unlike nodal DLBCL, only a limited number of genetic studies have been performed in PCNSL, partly due to lack of available tissue specimens. Because of the fragmented knowledge of the genomic basis, it is still a matter of debate whether they differ from systemic DLBCL with respect to their molecular features and pathogenesis and also if there is a CNS specific signature. We performed a comprehensive genomic study in a cohort of 22 immunocompetent (HIV- and EBV-) PCNSL. DNA was extracted from FFPE tissues (N=15) and frozen tissue (N=7). Samples were analyzed using a combination of aCGH (N=18), exome sequencing (N=10), mate-pair genome sequencing (N=2) and targeted sequencing (N=8). We found a complex karyotype with a median of 21 copy-number abnormalities (range 10–47), 6 structural abnormalities, 6 frameshift indels and 67 nonsynonymous mutations. By integrating mutation and copy number data we found a group of genes recurrently mutated and/or deleted in PNCSL. Remarkable findings were the high prevalence of MYD88 activating mutations (L265P/M232T/V217F), found in 69% of cases and the biallelic loss of CDKN2A (60%). A subset of recurrent abnormalities was exclusively found in PCNSL, and not being previously identified in systemic DLBCL. Thus, 11% of PCNSL have biallelic inactivation of TOX (a regulator of T-cell development) and PRKCD (protein kinase C delta), while another 17% of cases show focal monoallelic deletions/mutations in these genes. Finally, recurrent mutations have been identified in ATM, which have not been found in nodal DLBCL. Several other genes affected have been previously identified in nodal DLBCL, such as biallelic loss of TNFAIP3 (16%), PRDM1 (16%), GNA13, TMEM30A, B2M and CD58 (11% each), activating mutations of CD79B (28%) and CARD11 (19%) and translocations of BCL6 (22%). Components of the NF-kB pathways were altered in >90% of PNCSL. Pathway analysis also showed an enrichment of networks associated with immune response, proliferation, regulation of apoptosis and lymphocyte differentiation and activation. Finally, we searched for associations between genetic alterations and clinical outcome. We showed that deletions of 6q21 (PRDM1) and 6q23 (TNFAIP3) were both associated with shorter overall survival (p=0.007 and p=0.03, respectively). In summary, we report a genomic background in PCNSL similar to post-GC DLBCL but reinforcing the existence of a subset of abnormalities specific to PCNSL, suggesting their potential relevance in the disease pathogenesis. Additionally, the results obtained from FFPE samples are encouraging and larger archival tissue collections can now be analyzed in order to complement the still fragmented knowledge we have of the genetic basis of the disease. Disclosures: Stewart: Onyx: Consultancy, Research Funding; Millenium: Honoraria, Research Funding; Celgene: Honoraria; BMS: Honoraria. Fonseca:Medtronic: Consultancy; Otsuka: Consultancy; Celgene: Consultancy; Genzyme: Consultancy; BMS: Consultancy; Lilly: Consultancy; Onyx: Consultancy, Research Funding; Binding Site: Consultancy; Millennium: Consultancy; AMGEN: Consultancy; Cylene: Research Funding; Prognostication of MM based on genetic categorization of the disease: Patents & Royalties.

Abstract Abstract 1570 B-cell non-Hodgkin lymphoma encompasses a heterogeneous group of B-lymphocyte-derived malignancies that are characterized by chromosomal translocations involving the immunoglobulin (IG) gene loci and specific histological subtypes of disease are associated with a different spectrum of IG translocations. Marginal zone derived B cell lymphomas encompass three distinct entities: extranodal marginal zone B lymphoma (MZL) of mucosa associated lymphoid tissue (MALT), nodal MZL (NMZL), and splenic MZL (SMZL). MALT lymphoma is genetically unique and four mutually exclusive chromosomal translocations have been identified in this disease thus far. However, the known translocations are only present in a subset of cases suggesting that additional uncharacterized translocations or other genetic events may exist that contribute to disease development. In previous studies we characterized the novel t(X;14)(p11.4;q32) translocation in a patient with MALT lymphoma and found that GPR34, an orphan G-protein coupled receptor (GPCR), was highly expressed due to its juxtaposition to the IGHSA2 switch region. We then measured GPR34 mRNA expression in tissue biopsies from a panel of MALT, NMZL, SMZL, lymphoplasmacytic (LPL), diffuse large B cell (DLBCL), follicular (FL), and mantle cell (MCL) lymphomas. Expression of GPR34 was detected in all tissues examined, but was significantly increased in MALT (37 fold), LPL (23 fold), NMZL (18 fold), and SMZL (21 fold) compared to normal CD19+ B cells. GPR34 mRNA expression was also analyzed by gene expression profiling (GEP) of a panel of lymphomas or control lymphoid tissue and we confirmed elevated expression of GPR34 in the t(X;14) case and detected elevated GPR34 mRNA expression in MALT, LPL, NMZL, SMZL, and ABC DLBCL. When we grouped specimens by high and low expression of GPR34, a clear molecular subtype of SMZL could be identified and suggests that GPR34 high expressing tumors have a unique GEP. To confirm the qPCR and GEP analysis of GPR34 expression, we analyzed surface expression of GPR34 by flow cytometry of normal and malignant tissues and found that expression of GPR34 was detected on all MALT and SMZL B cells with an average DMFI of 2.08 (DMFI range 1.26–3.18, n=12) and on the JeKo-1 lymphoma B cell line (DMFI= 4.75). Analysis of CD19+ cells from normal controls (n=3) revealed a low level of GPR34 on (average DMFI =1.12). Little is known about the function of GPR34 and to further characterize the impact of GPR34 overexpression on cell signaling, OCI-LY19 lymphoma B cells and HeLa cells were transduced with GPR34 or a vector control. To determine if MAPK activity, a pathway regulated by GPCRs, was upregulated, the phosphorylation status of ERK1/2 in GPR34 or control cells was analyzed and we found that ERK1/2 was constitutively phosphorylated at significantly higher levels in GRP34 expressing cells. To further explore which signaling pathways were affected by GPR34 overexpression, GPR34 or vector control cells were transfected with an AP-1, CRE, NF-kB, E2F, SRE, NFAT, or ISRE- luciferase reporter plasmid and GPR34 expressing cells had significantly increased luciferase activity driven by AP-1 (5.35-fold), CRE (4.7-fold), NF-kB (2.6-fold), and E2F (2.1) when compared to vector control cells. To determine the biologic impact of GRP34 overexpression, the proliferation rates of vector control and GPR34 cells were compared and we found that proliferation of GPR34 WT cells was significantly higher than that seen in the control. We next tested the effect of the MEK inhibitor on proliferation and saw a dose dependent decrease in proliferation of GPR34 expressing cells. We then tested the ability of GPR34 cells to generate colony formation in a soft-agar colony formation assay. After 3 weeks of culture, the GPR34 cells had formed significantly more colonies than the vector control suggesting that overexpression of GPR34 can result in increased anchorage-independent cell growth. Taken together, our results identify a novel translocation in MALT lymphoma, emphasize a novel role for GPR34 in regulation of gene expression and tumor cell growth, and suggest that MEK inhibitors may be useful in a subset of translocation–harboring or GRP34 high-expressing tumors. Disclosures: No relevant conflicts of interest to declare.

Abstract Background: The PI3K/mTORC pathway is upregulated in DLBCL and can be targeted with mTORC1 inhibitors such as everolimus. Everolimus has demonstrated single agent activity in relapsed DLBCL (Leukemia. 2011; 25(2):341-7). These data provide the rationale to combine everolimus with standard RCHOP-21 to improve the effectiveness of upfront therapy for DLBCL. Methods: A phase I study was designed to determine the maximum tolerated dose of everolimus on days 1-10 or 1-14 in combination with RCHOP-21 along with a feasibility cohort to examine response in patients with newly diagnosed CD20+ DLBCL. Response assessment was evaluated using PET/CT and standard criteria. Results: We previously reported (J Clin Oncol 33, 2015 suppl; 8518) that in the phase I portion of trial N1085 that the dose of everolimus recommended for further study was everolimus 10 mg daily days 1-14; RCHOP day 1 and pegfilgrastim 6 mg day two for each of six 21-day cycles. The trial has now completed enrollment with a total of 26 patients. Two phase I patients were replaced during cycle 1 for personal, non-medical issues leaving 24 eligible patients for response assessment. The median age was 59.5 years (23 - 78); 42% were female; 18 (75%) stages III/IV; 12 (50%) had an elevated LDH; 29% had a high IPI score; and 4 (17%) had B-symptoms. Genotype was performed by immunohistochemistry using the Hans algorithm and 54% (13/24) were non-GCB; 13 (5 GCB, 8 non-GCB) had FISH for double hit and all were negative. Twenty-one (88%) patients received everolimus at 10 mg d1-14; the other three patients received 10 mg d1-10. Twenty-two (92%) patients received all 6 cycles. All patients have now completed therapy and the overall response rate was 96% (23/24) with 23 patients attaining functional CR by PET/CT. The remaining patient went off study for refusal in cycle 1, received further RCHOP-21 off study, and attained a CR off study. The median follow-up for the 24 patients is now 16.8 months (7.3 - 35.7) with 20 patients having ≥12 months of follow-up and 8 patients having ≥24 months of follow-up. To date, none of the 24 patients have died and none have experienced relapse with DLBCL. One patient relapsed 16 months from DLBCL diagnosis with a biopsy-proven follicular grade 1 NHL and received off-study Zevalin and achieved a second CR. The most common grade 3/4 toxicity was hematologic with 71% of patients having grade 4. Five (21%) patients had febrile neutropenia. Only 1 patient had grade 3 hyperglycemia and 3 patients had grade 3 hypertriglyceridemia. Reversible rash and pneumonitis were observed in 1 case each. Conclusions: The mTORC1 inhibitoreverolimus at 10 mg daily d1-14 of a standard RCHOP-21 cycle is tolerable with a 96% CR rate in both GCB and non-GCB DLBCL. With a median follow-up of 16.8 months and 8 patients out ≥24 months, the lack of DLBCL relapse is encouraging. Longer follow-up and a larger trial will be necessary to confirm the benefits of this novel combination. Clinical trial information: NCT01334502 Disclosures Off Label Use: Everolimus is an mTOR inhibitor which has activity in B cell lymphomas. It is being investigated in combination with SOC therapy for newly diagnosed DLBCL to examine potential toxicity as well as potential for enhanced disease response.. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding.

Abstract Introduction: "High grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements" (HG DH/THL) is a new diagnosis per the revised 2016 WHO classification. It has been colloquially called "double hit/triple hit lymphoma" and is significant for its aggressive clinical course. However, under this umbrella diagnosis there are several morphologic and cytogenetic variants with either controversial or unknown clinical significance. Herein, we investigate the prognostic significance of several of these parameters, including morphology, immunoglobulin gene (IG) vs non-IG MYC translocation partners, and BCL2/BCL6 translocation status in HG DH/THL in the Mayo Clinic Rochester practice. Materials and methods: All cases, which were identified through the Mayo Clinic Lymphoma Database, University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), and the Mayo Clinic Cytogenetics Laboratory, had diffuse large B-cell lymphoma (DLBCL) or high grade B-cell lymphoma (HGBCL) morphology, were CD20-positive, and had a MYC translocation with concurrent BCL2 and/or BCL6 translocations. Morphology was re-reviewed by four hematopathologists when possible. Cell of origin (germinal center B-cell (GCB) vs non-GCB phenotype) was determined by paraffin section immunohistochemistry using the Hans classifier. Interphase FISH was performed on either tissue paraffin sections or bone marrow aspirate smears using a breakapart probe for MYC, followed by dual fusion probes for IGH/MYC, IGL/ MYC and IGK/MYC, a BCL6 breakapart probe, and either a BCL2 breakapart probe or an IGH/BCL2 dual fusion probe. Outcome analysis was restricted to patients with de-novo HG DH/THL or HG DH/THL at transformation of a previously diagnosed low-grade lymphoma and who were treated with anthracycline-based chemotherapy. Overall survival (OS) was defined as time from DH/THL diagnosis to death from any cause. Results: There were 100 patients with a median age of 61 years (range 29-87). The consensus re-review morphologic diagnosis (n=65) was HGBCL in 39 (60%) and DLBCL in 26 (40%). The HGBCL group had inferior survival (2-year OS = 35%) compared to DLBCL (2-year OS=62%, p= 0.058). By interphase FISH, the MYC translocation partner was an IG gene (IG/MYC) in 52 cases (60%; 39 IGH, 6 IGK and 7 IGL) and a non-IG gene (non-IG/MYC) in 35 cases (40%). No difference in OS was identified between IG/MYC and non-IG/MYC cases (p=0.85, Figure 1). By FISH, 87 cases (87%) had a BCL2 translocation (59 MYC/BCL2, 20 MYC/BCL2/BCL6, and 8 MYC/BCL2/[BCL6 unknown]) and 13 (13%) lacked a BCL2 translocation (MYC/BCL6). Those with a BCL2 translocation were all of GCB phenotype (N=85), while 6 of 12 of the MYC/BCL6 cases (50%) were of non-GCB phenotype (p <0.0001). All 13 MYC/BCL6 cases were de novo diagnoses, while 38% of cases with a BCL2 translocation represented either transformation (n=22) or recurrence (n=11) events (p=0.025). The MYC/BCL6 group had better survival (2-year OS=73%) than those with BCL2 translocation (2-year OS=43%, p= 0.13). Conclusion: As HG DH/THL's frequently have morphologic characteristics of DLBCL (40% in this series), it is important to perform complete interphase FISH analysis on all cases with DLBCL or HGBCL morphology to exclude the possibility of HG DH/THL. Furthermore, within the diagnosis of HG DH/THL, there are several morphologic and cytogenetic subtypes that are biologically and clinically significant. High grade morphology (HGBCL) tends to predict for a more aggressive clinical course independent of all other parameters (p= 0.058). Unlike a recent report (Blood 2015;126:2466), our data suggest MYC translocation partner (IG versus non-IG) may have no impact on overall survival (Figure 1). HG DH/THL's with a BCL2 translocation appear restricted to GCB phenotype, frequently represent either transformation or recurrence events, and tend to have inferior OS. In contrast, those without BCL2 translocations may be of either GCB or non-GCB phenotype, typically arise de novo, and tend to have a superior OS. Careful morphologic review and complete interphase FISH studies are essential in all HG DH/THL for prognostic and potential therapeutic purposes. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract Background: B-cell lymphomas with a MYC/8q24 rearrangement coupled with translocations involving BCL2 and/or BCL6, often referred to as double hit or triple hit (DH/TH) lymphomas, typically have an aggressive clinical course. A new WHO subtype, "high grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements", has been established for this entity (Swerdlow et al. Blood; 127: 2375-2390, 2016). Herein we report the treatment and outcomes of DH/TH patients at our institution. Materials and Methods: Cases were identified through the Mayo Clinic Lymphoma Database, University of Iowa/Mayo Clinic SPORE Molecular Epidemiology Resource (MER), and the Mayo Clinic Cytogenetics Laboratory. Interphase FISH was performed clinically on either paraffin sections of the tissue specimens or on smears of the bone marrow aspirate specimens using break-apart probes for MYC and BCL6, dual fusion probes for IGH/MYC, IGL/MYC, and IGK/MYC, and either a BCL2 break-apart probe or an IGH/BCL2 dual fusion probe. Consensus pathology re-review was performed to define morphology as diffuse large B-cell lymphoma (DLBCL) vs. high-grade B-cell lymphoma (HGBCL). Patients with de-novo DH/TH or diagnosis of DH/TH at the time of transformation of a previously diagnosed low-grade lymphoma and who were treated with anthracycline-based chemotherapy were included in this analysis. Patients with DH/TH first identified at the time of recurrent aggressive B-cell lymphoma were excluded. Overall survival (OS) was defined as time from DH/TH diagnosis to death from any cause. EFS12 was defined as event-free status 12 months from diagnosis of DH/TH. Results: Clinical outcome analysis was performed on 71 patients (Table 1). The median age was 61 years (range 29-82). 60 patients had de-novo DH/TH and 11 patients had transformation of a previously diagnosed low-grade lymphoma. In 65 cases in which there was consensus morphology on pathology re-review, there were 39 (60%) with HGBCL morphology and 26 (40%) with DLBCL morphology. At a median follow-up of 21 months (range 1-87), the event free survival at 12 months was 43%, and the median overall survival (OS) was 22 months (95% CI: 13-NA). The OS at 5 years was 48% (95% CI: 36%-63%). Patients with DH/TH at transformation of previously diagnosed low-grade lymphoma had a very poor outcome (median OS=10.8 months, EFS12 = 10%), which was inferior to patients with de-novo DH/TH (P=0.0069). When compared to all other therapies, patients treated with R-CODOX-M/IVAC had better EFS12 (p=0.03) with a trend in improved OS (p=0.08) though this may be confounded by patient selection bias as these patients were significantly younger (p=0.0001) than patients treated with other anthracycline based regimens (table 1). Conclusion: In "high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements", induction failure occurs early. Although transformation to DH/TH from previously diagnosed low-grade lymphoma is associated with a particularly poor outcome, the overall survival for the entire cohort at 5 years was 48%, suggesting long-term cures in a subset of patients. Treatment with R-CODOX-M/IVAC may result in superior outcomes in patients less than 60 years of age. Table 1 Table 1. Figure Figure. Disclosures Ansell: BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Nowakowski:Celgene: Research Funding; Morphosys: Research Funding; Bayer: Consultancy, Research Funding.

Abstract Abstract 1580 Background: Extranodal Marginal Zone Lymphomas of Mucosa Associated Lymphoid Tissue (MALT) account for approximately 5% of all non-Hodgkin Lymphoma cases. Specific MALT lymphomas are characterized by distinct clinical features, treatment strategies, and outcome, depending on site of the disease. While previous reports have described clinical course and treatment of gastric and pulmonary MALT lymphomas, a paucity of data exist describing primary parotid MALT lymphoma. This is a single institution experience. Methods: Patients with primary parotid MALT lymphoma were identified from the Mayo Clinic Lymphoma Database since 1986. This database includes all consenting patients with lymphoma seen at Mayo Clinic Rochester. Clinical characteristics, treatment, and outcomes were collected. Pathology was reviewed by a lymphoma pathologist; WHO criteria were used for diagnosis. PFS and OS were assessed using the Kaplan-Meier method and Cox proportional hazard model was used to asses the impact of variables on PFS and OS. Results: Seventy-six consecutive patients with primary parotid MALT lymphoma were evaluated and treated at Mayo Clinic from 1986 to 2010. The median age at diagnosis was 60 years (18–90). 58 (76%) were female. 42 (55.3%) patients had a history of Sjögren's Disease and 51 (67.1%) had a history of autoimmune disorders. 52 (68.4%), 4 (5.3%), and18 (23.7%) had stage I, II, and IV disease, respectively. 2 cases did not have complete staging information. 6 (7.8%) and 2 (2.6 %) had bone marrow and lung involvement, respectively. No patients had GI tract, liver, or CNS involvement. Median estimated OS (overall survival) was 18.3 years and median PFS (progression free survival) was 7.9 years. ALC<0.96 (p=0.0162) were associated with shorter survival. Age, ECOG performance score, stage, LDH, and history of Sjögren's disease were not prognostic for overall survival. The treatment approach and PFS are outlined in the table. For stage I disease, outcomes were excellent with local therapy. The median estimated PFS was 7.9 years with 72% of patients undergoing surgery surviving at 8 years. Patients receiving radiotherapy had an estimated median PFS of 15.7 years and median OS of 18.3 years. In contrast, patients being observed had a median PFS of 5.5 years. The use of systemic therapy with chemotherapy, immunotherapy or in combination was associated with a median PFS of 7.4 years. Summary: Primary parotid MALT lymphoma is strongly associated with Sjögren's disease. This lymphoma is usually limited to the parotid and associated with a favorable prognosis. For limited disease, local treatment with radiation or surgery appears to be an effective treatment options. For extensive disease, both immunotherapy and chemotherapy are efficacious treatments. Further prospective studies and long-term follow up are needed to determine the optimal treatment approaches and efficacy of chemotherapy/immunotherapy regimens. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 4168 Background: Primary Pulmonary MALT lymphoma represents 15–20% of Extranodal Marginal Zone Lymphomas of Mucosa Associated Lymphoid Tissue (MALT). In contrast to the more common gastric MALT lymphoma, natural history, prognosis and treatment outcomes for primary pulmonary MALT lymphoma are not well defined. Herein, we report a single institution experience. Methods: Consecutive patients with primary pulmonary MALT lymphoma registered in the Mayo Clinic Lymphoma Database, which includes all consenting patients with lymphoma seen at Mayo Clinic Rochester, were reviewed for clinical features, treatment outcome progression free survival (PFS) and overall survival (OS). The pathology for all patients was centrally reviewed by hematopathologist and the diagnoses were based on WHO lymphoma classification criteria. PFS and OS were assessed using the Kaplan–Meier method and the Cox proportional hazard model was used to assess the impact of variables on PFS and OS. Results: Between December 1986 and June of 2009, ninety-seven patients with primary pulmonary MALT lymphoma were enrolled. The median age at diagnosis was 63 years (range 31–87). There were 43 (44%) males. The initial presentation was a unilateral pulmonary lesion (n=47, 48%), bilateral pulmonary lesions (n=41, 42%), and pulmonary lesion with intrathoracic lymphadenopathy (n= 4, 4%). Bone marrow involvement and presence of B symptoms were 4, 4% and 5, 5%, respectively. International Prognostic Index (IPI) was 0–1, 2–3 and 4–5 in 69, 25 and 1 patient(s) respectively. The median follow-up was 10.4 years. The estimated median OS was 13. 6 years and the median PFS was 5.5 years (Figure). In a multivariate analysis, age >60 (p=0.02) and ECOG PS>2 (p=0.01) were associated with shortened survival. The IPI and age adjusted IPI were not predictive of overall survival. The treatment outcomes for the most common treatment modalities are summarized in the Table below. The median PFS of the 38% of patients who had a complete surgical resection was excellent at 11.2 years; whereas for observed patients with residual disease after biopsy was 3.2 years. Only 8 patients received single agent rituximan with relatively low response rate. Summary: The prognosis of primary pulmonary MALT lymphoma is favorable, with a median survival of over 13 years. In patients with resectable disease, surgery alone is associated with excellent disease control. Further prospective studies are needed to define the optimal treatment of primary pulmonary MALT lymphoma. Disclosures: No relevant conflicts of interest to declare.