Citations

Abstract The peripheral blood absolute lymphocyte/monocyte ratio at diagnosis (ALC/AMC-DX) predicts survival in diffuse large B-cell lymphoma (DLBCL). However, a limitation of the ALC/AMC-DX is its inability to sequentially assess the host/tumor interaction during treatment. Therefore, we studied the ALC/AMC ratio, as a surrogate marker of host immunity (i.e., ALC) and tumor microenvironment (i.e., AMC), at each RCHOP treatment cycle as a predictor for clinical outcomes. From 2002 until 20011, 107 DLBCL patients originally diagnosed, treated with six cycles of RCHOP, and followed at Mayo Clinic qualified for the study. Using the receiver operating characteristic and internally validated using the k-fold cross validation; an ALC/AMC ratio ≥ 1.1 was identified as the cut-off value at each RCHOP treatment cycle to discriminate for the binary clinical outcome of death/survival. Univariate analysis revealed the ALC/AMC ratio ≥ 1.1 at each RCHOP treatment cycle was a predictor for overall survival (OS) and progression-free survival (PFS). To explore whether the patterns of ALC/AMC ratio recovery during the RCHOP treatment cycles had a prognostic value, we performed an unsupervised hierarchical clustering on the studied ALC/AMC ratio and identified four patient clusters, A-D. Eighty percent of patients in cluster C had an ALC/AMC ratio ≥ 1.1 during all the cycles, the other 20% had an ALC/AMC ratio ≥1.1 in one cycle; in cluster D patients, the ALC/AMC ratio was ≥ 1.1 between cycles 2 and 5 and none had an ALC/AMC ratio < 1.1; in cluster A patients, 73% of patients only had an ALC/AMC ratio ≥ 1.1 in one cycle and 27% in two cycles; and cluster B patients had 85% of patients with an ALC/AMC ratio < 1.1 during all the cycles. Inferior OS and PFS were progressively observed in clusters of patients with fewer cycles achieving an ALC/AMC ratio ≥ 1.1. Patients in clusters C had superior outcomes compared with patients in clusters B. Thus, we dichotomized patients into patients with an ALC/AMC ratio ≥ 1.1 during any cycle versus patients with an ALC/AMC ratio < 1.1 during all cycles. By multivariate analysis, the stratification of patients into ALC/AMC ≥ 1.1 during any cycle versus ALC/AMC < 1.1 during all cycles was an independent predictor for OS [Hazard ratio (HR) = 0.02, 95% CI (0.006-0.08), p< 0.0001], and PFS [HR = 0.06, 95% CI (0.02-0.15, p< 0.0001] when compared with the International Prognostic index The median OS for patients with an ALC/AMC ratio ≥ 1.1 during any cycle versus patients with an ALC/ACM ratio < 1.1 during all cycles was not reached versus 1.7 years with 5 years OS rates of 97% (95% CI, 90%-99%) versus 0%, p< 0.0001, respectively. The median PFS for patients with an ALC/AMC ratio ≥ 1.1 during any cycle versus patients with an ALC/AMC ratio < 1.1during all cycles was not reached versus 0.9 years with 5 years PFS rates of 83% (95% CI, 72%-90%) versus 0%, p< 0.0001, respectively. The ALC/AMC ratio during RCHOP treatment cycles is a predictor for survival and provides a platform to develop therapeutic modalities to manipulate the ALC/AMC ratio during chemotherapy to improve clinical outcomes in DLBCL. Disclosures: No relevant conflicts of interest to declare.

Abstract The lymphocyte-to-monocyte ratio at diagnosis (LMR-D) has been reported to be a prognostic factor for clinical outcomes in both T-cell and B-cell lymphomas. However, there are no reports testing the prognostic ability of LMR-D in patients diagnosed with de novo double/triple hit diffuse large B cell lymphoma (DLBCL). Thus, we set out to investigate if the LMR-D is a prognostic factor for survival in de novo double/triple hit lymphomas. From 10/5/1998 until 1/16/2015, thirty-four patients with de novo double/triple hit DLBCL were identified for this study. Double and triple hit were defined by interphase FISH evaluating three fusion signals to identify the BCL2 translocation and IGK/MYC D-FISH probe to identify whether the partner is IG or non-IG. Interphase fluorescence in situ hybridization (FISH) was performed on paraffin sections using probes that included 8q24 (5'MYC, 3'MYC); t (2;8), IGK/MYC; t(8,14), MYC/IGH; t(8;22), MYC/IGL; 3q27 (3'BCL6, 5'BCL'6); and 18q21 (3'BCL2, 5'BCL2). The cohort included 14 females and 20 males. The median follow-up for the cohort was 9.0 months (range: 0.4-72.6 months). Using the median for the LMR-D as the cut-off value, patients with a LMR-D ≥ 1.2 experienced superior overall survival (OS) [Hazard ratio (HR) of 0.127, 95% confidence interval (CI) of 0.019-0.530, p < 0.004] and progression-free survival (PFS) [HR of 0.107, 95 CI of 0.024-0.335, p < 0.0001]. The median follow up for OS for patients with a LMR-D ≥ 1.2 was not reached with a 5-year OS rate of 82% (95% CI of 49%-95%) compared with a median follow-up of 10 months for patients with a LMR-D < 1.2 with a 0% 5 year OS rate, p < 0.003 (Figure 1A). The median PFS for patients with a LMR-D ≥ 2 was not reached with a 5 years PFS of 74% (95%CI, of 43%-91%) compared with a median follow-up of 4.7 months for patients with a LMR-D < 1.2 and 0% 5 year PFS rate, p < 0.0001 (Figure 1B). After adjusting for the International Prognostic Index, multivariate analysis showed that the LMR-D remained an independent prognostic factor for OS [HR = 0.180, 95% CI of 0.254-0.784, p < 0.02] and for PFS [HR of 0.127, 95%CI of 0.029-0.409, p < 0.0003]. In spite of the small cohort of de novo double/triple hit DLBCL, the LMR-D was identified as a prognostic factor for clinical outcomes for this specific set of aggressive lymphomas. Further studies are warranted to confirm our findings. Table.LMR-D ≥ 1.2, N = 18Events = 2LMR-D < 1.2, N = 16Events = 8P < 0.003LMR-D ≥ 1.2, N = 18Events = 3LMR-D < 1.2, N = 16Events = 14P < 0.0001Figure 1AB Figure 1. Figure 1. Disclosures Maurer: Kite Pharma: Research Funding. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding. Off Label Use: New agent in a combination regimen..

Abstract Background: The salivary gland is one of the most common sites of involvement by non-gastric extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT). This multicenter, international trial sought to characterize the clinical course, treatment and outcome of patients with salivary gland MALT lymphoma. Methods: Patients were identified from multiple international sites including the Mayo Clinic Lymphoma Database (n=89), three International Extranodal Lymphoma Study Group (IELSG) cohorts (n=138), and the University of Athens (n=21). All patients had biopsy-confirmed MALT lymphoma of the salivary gland by WHO criteria. Clinical characteristics, treatment, and outcomes were obtained from the respective patient databases. Survival probability was estimated using the Kaplan-Meier method and compared between groups with the Wilcoxon or log-rank. The impact of variables on survival was assessed by the Cox proportional hazards model. Results: Patients and clinical features: From 1983 to 2012, 247 patients with MALT lymphoma were included. Clinical characteristics are shown in Table 1. The median age at diagnosis was 59, and the male-to-female ratio was 1:3. The majority of patients (76%) presented with limited stage disease, and the parotid gland was the most common site of involvement (78%). There was a history of antecedent autoimmune disease in 41% of patients, and Sjögren’s disease was the most common (83%). Treatment: Information on initial treatment was available on 242 patients. 137/242 patients (57%) initially received local therapy with either surgery (n=81), radiation (n=26), or both (n=30). Of these, 25 received adjuvant systemic therapy. 90/242 patients (37%) were treated initially with systemic therapy, of whom 54% had localized and 46% had stage IV disease. Rituximab was used alone (n=16) or in combination with chemotherapy (n=26) in 42 of the 90. 15/242 patients (6%) were initially observed. Survival: The median OS for all patients was 18.3 years. PFS following primary therapy was 9.3 years. There was no difference in the outcomes between patients receiving local or systemic therapy in first line for all patients, or for those with stage I or II disease. On univariate analysis age <60, stage, IPI, normal LDH, the presence of Sjögren’s disease, and treatment with rituximab were associated with improved overall survival. Age <60, low to intermediate IPI and normal LDH were associated with improved PFS. On multivariate analysis, age<60, and IPI were associated with improved OS and PFS and Sjögren’s disease was associated with improved OS. Relapse/progression: The site of progression was known in 51 of 76 patients who progressed. 15 (29%) patients progressed in the same salivary gland or regional nodes; in 16 (21%) recurrence involved the contralateral salivary gland; 20 (31%) had distant progression. Relapse histology was identified in 30. The most common pathology at relapse was MALT (n=28), with one patient progressing to diffuse large B-cell lymphoma. A second patient developed a mantle cell lymphoma. Conclusions: Salivary gland MALT lymphoma commonly presents at an early stage, and has a favorable prognosis with a median OS of 18 years. Surgical or radiation therapy does not appear to have benefit over systemic therapy. Patients with Sjögren’s disease appear to have a better survival. The role of rituximab and optimal first-line therapy should be evaluated further in prospective trials. Table 1: Characteristics of 247 patients with salivary MALT Characteristic N (%) Age, median; range 59; 18-93 Sex, Male: Female 62: 185 (25: 75) Primary site of involvement Parotid 193 (78) Submandibular 12 (5) Other/not specified 42 (17) Extent (unilateral: bilateral) 89:21 Missing data 137 Autoimmune disorder* 101(41) Sjögren’s 84 (33) Rheumatoid arthritis 9 (4) Raynaud’s phenomenon 8 (3) Scleroderma 5 (2) Other 19 (8) Stage IE 147 (59) IIE 42 (17) IV 56 (23) Missing data 2 (1) IPI Score Low (0-1) 126 (51) Low-Intermediate (2) 20 (8) High-intermediate (3) 21 (8) High (4-5) 5 (2) Missing data 75 (31) Elevated LDH 17 (7) ECOG PS 0-1 246 2 1 Extranodal sites 1 58 (23) 2 187 (76) Missing data 2 (1) B symptoms 9 (4) * Percents may not equal 100 as some patients had more than one disorder. Figure One: Overall survival of patients with and without Sjögren’s disease Figure One:. Overall survival of patients with and without Sjögren’s disease Disclosures Nowakowski: Celgene, Morphosis: Consultancy. Zucca:Roche, Mundipharma, Novartis, Jannsen, Celgene: Consultancy, Honoraria, Research Funding.

Abstract Background: Follicular lymphoma (FL) is an indolent lymphoma generally considered incurable with current standard therapies. Recent advances have resulted in prolongation of overall survival (OS) for patients with FL such that death from competing causes may now limit the mortality impact of FL in some patient groups. Identification of patients for whom FL related mortality is expected to be minimal, or conversely those at high risk of disease related mortality, is highly clinically relevant. We recently reported (Maurer et al, JCO 2014;32:1066-73) that event-free survival (EFS) at 24 months from diagnosis is a robust endpoint for disease related outcome in patients with diffuse large B cell lymphoma (DLBCL). Here we use the same approach to assess if landmark timepoints of EFS can stratify subsequent OS in FL. Methods: All newly diagnosed grade 1-3a FL patients enrolled on the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER) from 2002-2011 were eligible. Patients with grade 3b FL, transformation, or presence of DLBCL at diagnosis were excluded. EFS was defined as time from diagnosis to progression, relapse, re-treatment, or death due to any cause. EFS12 was defined based on EFS status 12 months after date of diagnosis; we also assessed EFS at 24 months. OS was defined as time from a specific timepoint (diagnosis, event, or EFS12) until death due to any cause. OS was compared to age and sex matched survival in the general US population using an expected survival approach and standardized mortality ratios (SMR) and 95% confidence intervals (CI). Outcomes were examined in all patients as well as selected subsets defined by initial treatment. Replication was performed using a Lyon, France hospital registry of newly diagnosed grade 1-3a FL patients enrolled from 2002-2010 with survival compared to French population data. Results: 936 patients with grade 1-3a FL were eligible from the MER. The median age at diagnosis was 60 years (range 19-91) and 53% were male. 86% had grade 1-2 disease and 14% grade 3a disease. 23% had high-risk disease (FLIPI score ≥3). 347 (37%) were initially treated with alkylator or anthracyline based immunochemotherapy (IC), 113 (12%) rituximab monotherapy (RM), and 318 (34%) were initially observed; the remaining patients received radiation for limited stage disease (8%), chemotherapy without rituximab (4%), or other therapy (5%). At a median follow-up of 59 months (range 1-131), 403 patients (43%) had an event and 120 patients (13%) had died; 155 patients (17%) failed to achieve EFS12. From diagnosis, patients with FL had inferior OS compared to the general population (SMR=1.24, 95% CI: 1.03-1.48, p=0.018); results were similar for patients with grade 1-2 (SMR=1.23) and grade 3a (SMR=1.29) disease. The survival deficit was eliminated in patients who achieved EFS12 (SMR=0.85, 95% CI: 0.66-1.09, p=0.20, Fig 1a), and so we did not pursue modeling EFS24. In contrast, patients with a non-death event (relapse, retreatment, or progression) within 12 months of diagnosis had inferior subsequent OS (SMR=3.90, 95% CI: 2.89-5.25, p=4.8x10-19, Fig 1b). These results were replicated in 153 FL patients from the Lyon registry: patients who achieved EFS12 had equivalent subsequent OS to the general French population (SMR=0.82, 95% CI: 0.39-1.72, p=0.60, Fig 1c), while patients who failed to achieve EFS12 had poor subsequent OS (SMR=4.16, 95% CI: 1.34-12.91, p=0.013, Fig 1d). In subset analysis of the MER, patients achieving EFS12 initially treated with IC (SMR=0.98, 95% CI: 0.63-1.54, p=0.93), RM (SMR=0.66, 95% CI: 0.31-1.38, p=0.27), or observation (SMR=0.73, 95% CI: 0.47-1.15, p=0.18) had equivalent OS to the population. In contrast, for patients not achieving EFS12, OS after event was inferior for those treated with IC (SMR=15.0, 95% CI: 10.22-22.05, p=2.0x10-43) or RM (SMR=4.96, 95% CI: 1.24-19.84, p=0.023), while trending towards inferior for those initially observed (SMR=1.55, 95% CI: 0.81-2.99, p=0.19). Summary: Events within the first 12 months of diagnosis are associated with poor OS in FL, especially in patients treated with IC, while patients achieving EFS12 have excellent subsequent survival, overall and in the main treatment subsets. Prognosis for FL patients should be recalibrated at 12 months from diagnosis. EFS12 will be useful in counseling and should be considered as an endpoint in studies of newly diagnosed FL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract To date, whole genome and exome sequencing studies of follicular lymphoma (FL) have primarily focused on identification of small site mutations that are recurrent in FL tumorigenesis or involved in tumor clonal evolution. A comprehensive genomic and transcriptomic survey of various mutation types including large structural variants (SVs) in FL cases with detailed clinical annotations and long-term follow-up has not been accomplished. To gain insight into genetic biomarkers that may predict clinical features, we performed exome and whole genome mate-pair sequencing of fresh frozen tumor and paired peripheral blood DNAs, and transcriptome sequencing of tumor RNAs, from 8 FL patients. The patients we selected were either below the median age of FL onset (n=7, median 54.5 yrs) or had a family history of lymphoma (n=1). These patients were clinically diverse, and included patients who had Grade 1 or 2 disease (n=4), classified as “indolent”; and patients with Grade 3a disease (n=2) or who subsequently had pathologic transformation (n=2), classified as “aggressive”. The coding regions of the genome (exome) were captured using Agilent SureSelect Target Capture Kit V2.0, and sequenced at 100-bp paired-end. The single nucleotide variants (SNVs) and small insertions and deletions (INDELs) were called using The Genome Analysis Toolkit (GATK), and the exon level copy number variants (CNVs) we identified using patternCNV. The whole-genome mate-pair libraries of both normal and tumor DNAs with 3kb insert sizes were sequenced paired end at 50-bp. The large SVs of CNVs, large INDELs, translocations, and inversions were identified using the SnowShoes-SV algorithm. The RNA sequencing libraries of 8 FL tumors were constructed using Illumina TruSeq protocol, and sequenced at 50-bp paired end. The RNA-Seq data were analyzed using TopHat and the fusion transcripts were identified using SnowShoes-FTD. Our analysis of SNVs and INDELs revealed mutations in previously reported genes including MLL2, CREBBP, TNFRSF14, and histone cluster genes (HIST1H2AM, HIST1H2BD). In addition, we identified novel recurrent mutations in cysteine-rich PAK1 inhibitor (CRIPAK) in 25% of the tumors. In a secondary analysis performed by Sanger sequencing or re-analysis of publically available RNA sequencing data, we identified CRIPAK mutations in 44% of FL (n=32) and 28% of DLBCL tumors (n=102). Bioinformatics analysis shows that the coding region of CRIPAK is highly enriched with the protein functional domain, post-SET, which is usually found in histone lysine methyltransferases (HMTase) genes including MLL2 and EZH2 that are known to be important in lymphomagenesis. Interestingly, CRIPAK is part of the same regulatory network consisted of previously identified lymphoma genes including MLL2, EZH2, CREBBP, and EP300, according to the shortest path algorithm by MetaCore (Philadelphia, Pennsylvania). Recurrent SVs identified in the FL tumors included the well-known IGH-BCL2 translocation, or t(14;18), in 6 out of 8 cases (75%) and the chr1q amplifications in 4 out of 8 (50%) tumors. Other non-recurrent large CNVs involving entire chromosomes or chromosome arms, as well as other inter- and intra-chromosomal structural variants were detected in individual tumors. In addition, we identified and validated 6 fusion transcripts from the transcriptome sequencing data in 3 out of 8 cases (38%). While our sample size is small, we found that SNVs and INDELs in MLL2, CREBBP, TNFRSF14, CRIPAK, and histone cluster genes, as well as t(14;18), did not distinguish indolent or aggressive tumors. However, all aggressive (4/4, 100%) and none of the indolent tumors had gains in chr1q; and the presence of RNA fusion transcripts were observed in aggressive tumors only (3/4, 75%). Additionally, we found that aggressive tumors had higher numbers of genes with point mutations (SNVs and short INDELs) (40 ± 7.6 vs. 26 ± 2.6; aggressive vs. indolent), higher numbers of genes impacted by copy number aberrations (1060 ± 263.7 vs. 233 ± 133.9), and higher numbers of large SVs (24 ± 10 vs. 6 ± 1.6). Taken together, our comprehensive analysis of 8 FL tumors reveals genetic diversity among newly diagnosed FL patients, identifies novel and recurrent mutations in CRIPAK, and finds that high tumor complexity and DNA instability may be indicators of aggressive disease. Disclosures No relevant conflicts of interest to declare.

Abstract Abstract 689 Background: Lenalidomide was demonstrated to have significant single agent activity in relapsed aggressive B cell lymphoma (J Clin Oncol. 2008;26:4952–7, Ann Oncol. 2011;22:1622–7). In a phase I study, we previously demonstrated that Lenalidomide 25 mg day 1–10 of the cycle can be combined with RCHOP21 and this combination does not result in dose delays or increased toxicity (Leukemia 2011;12:1877–81). We now present phase 2 results of R2CHOP in treatment of patients with aggressive B-cell lymphoma. Methods: Eligible patients were adults with newly diagnosed CD20 positive diffuse large B cell (DLBCL) or grade 3 follicular lymphoma (FL). The response was evaluated using PET/CT by standard criteria (J Clin Oncol. 2007;25:579–586). The progression free survival (PFS) was defined as time from diagnosis to disease progression or death. Results: 51 patients - 6 enrolled at the MTD in phase 1 portion of the study and 45 in phase 2 portion were included in the analysis. The median age was 65 years (range, 19–87). 35% of patients were 70 and older. 63% (32/51) were males. 47 patients (92%) had DLBCL and 4 (8%) patients had FL grade 3. The international prognostic index (IPI) was low, low-intermediate, high-intermediate and high in 8 (15%), 18 (35%), 18 (35%) and 7 (14%) patients respectively. 31 patients (60%) had stage 4 disease. Hematological toxicities were: grade 3 and 4 thrombocytopenia (20% and 20% of patients respectively); grade 3 and 4 neutropenia (18% and 71% of patients respectively). Overall 27% of patients experienced a grade 3 or higher non-hematological toxicity at least possibly related to treatment. The most frequent were febrile neutropenia (10%), nausea (4%), urinary tract infection (4%), vascular access complication (4%), and dehydration (4%). 1 patient (2%) developed thrombosis. There was one death (2%) secondary to bowel perforation/sepsis. For 47 patients evaluable for response, the overall response (ORR) and complete response (CR) rates were 98% and 83% respectively. The PFS was 73% at 12 months (Figure). Since the enrolled patients represented a relatively high-risk group (49% intermediate high or high IPI, significant proportion of elderly male patients), the PFS in R2CHOP was compared to PFS in a contemporary cohort of 87 consecutive patients with DLBCL participating in Mayo Clinic Lymphoma Database and treated with standard RCHOP alone. The PFS was 62% at 12 months in this cohort and was inferior to R2CHOP (Figure). Conclusion: Lenalidomide combined with standard R-CHOP21 chemotherapy (R2CHOP) demonstrates predictable safety profile. The ORR and CR rates and PFS are encouraging in elderly high IPI patients, and compared favorably to the R-CHOP treated historical cohort with similar clinical characteristics. A randomized trial will be needed to confirm the benefits of this novel combination. Disclosures: Off Label Use: lenalidomide in treatment of NHL. Reeder:Celgene: Research Funding. Ansell:Seattle Genetics, Inc.: Research Funding; Celgene Corporation: Consultancy.

Abstract Abstract 92 BACKGROUND: All somatic cell types, including all B lineage cells, constitutively express a number of DNA repair proteins to maintain genomic stability and thwart tumorigenesis in the face of ongoing constitutive levels of DNA damage. Compromises in expression of these essential DNA repair factors have been shown to readily induce the development of various cancers including B cell lymphomas, suggesting expression levels are tightly regulated and limited in quantity. In germinal center (GC) B cells, however, additional DNA repair capacity is likely required to counterbalance the heightened level of mutagenic activity owing to the induced expression of activation-induced cytidine deaminase (AID) during somatic hypermutation (SHM). AID is a DNA editing enzyme which introduces somatic mutations into immunoglobulin (Ig) V regions at an estimated rate which is almost a million-fold higher than the spontaneous rate in somatic cells. HYPOTHESIS: We hypothesize that to maintain the genomic wellness of GC B cells which are undergoing SHM, there is a need for induction of an accompanying robust DNA repair system. We further hypothesize that inefficient induction of these repair genes may predispose to malignant transformation. METHODS: Using tonsillar tissue sections and purified tonsillar B cell subpopulations, we compared expression levels of various DNA repair genes and related these levels to AID expression across the subsets using immunohistochemistry, real-time RT-PCR, and Western blot analysis. To characterize the nature of signals capable of inducing expression levels of AID and/or DNA repair proteins, peripheral blood B cells were activated in vitro using a panel of stimuli, including coculture with activated CD4 T cells. As a surrogate measure of mismatch repair (MMR) activity in the relative absence of T cell help, we quantitated the number of somatic hypermutations at A/T sites in the Ig heavy chain variable (IGHV) region genes in a collection of IGHV sequences obtained from normal B cells and HIV-related lymphoma cells. RESULTS: Using immunohistochemistry, we observed that, similar to the expression of AID, DNA MMR genes are significantly induced in tonsillar GC B cells. These results were further validated using a more sensitive real-time RT-PCR assay and analysis by Western blotting. By expanding our DNA repair gene panel, we observed that proteins of homologous recombination, base excision repair and DNA single strand break signalling pathway are also similarly induced in GC B cells at RNA, protein, and functional levels compared to their expression in naïve and memory B cells. By contrast, expression of non-homologous end joining and DNA double strand break signalling molecules are unchanged. We have termed this selective induction of repair mechanisms in GC B cells as somatic hyperrepair (SHR). To identify pathways that lead to the activation of AID and SHR, we used an in vitro system and a variety of stimuli and we discovered that multiple B cell stimuli including CpG, CD40L, and anti-BCR could each independently induce the expression of AID while SHR induction strictly required the engagement of CD4+ T cells. This provocative observation suggests a novel role for CD4+ T cells in mitigating tumorigenesis of post-GC B cells through their ability to induce the SHR pathway in cells that have been induced to undergo SHM. To demonstrate the possible role of SHR in lymphomagenesis, we analysed the mutation pattern of IGHV genes from a panel of B cell lymphomas obtained from HIV infected (CD4+ T cell suppressed) patients. We found that HIV-related lymphoma cells displayed a significantly lower frequency of SHM at A/T positions relative to normal memory B cells, indicative of compromised MMR of their precursor cells during GC transit. Our findings resolve the lingering paradox that B cell malignancies are overwhelmingly prevalent under T cell suppression conditions such as HIV infection, post-organ transplant, and aging. Finally, our results also suggest for the first time that mounting efficient tumor suppression for some cells may depend on signals transmitted by neighboring cells and the specific microenvironment. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 684 Background. Obesity has been associated with an increased risk of developing of lymphoma, particularly DLBCL. Genetic variation in several energy balance genes, including leptin (LEP), its receptor LEPR, ghrelin (GHRL) and neuropeptide Y (NPY) have been shown to modulate risk of lymphoma, although their impact on survival is not known. In contrast, recent studies suggest that patients either overweight (Body Mass Index (BMI), 25 to<30 kg/m2) or obese (≥30 kg/m2) may have a superior prognosis in DLBCL, although its impact in FL and in the current treatment era is not known. We evaluated the association of BMI at the time of diagnosis, 2 years prior to diagnosis and at ages 18, 35 and 50 years, along with germline genetic variation in selected energy balance genes with event-free (EFS) and overall (OS) survival in DLBCL and FL. Methods. We evaluated these associations in a prospective cohort of newly diagnosed DLBCL (N=764) and FL (N=649) patients enrolled at the Mayo Clinic and University of Iowa from 2002–2009 as part of the Molecular Epidemiology Resource. Peripheral blood DNA, clinical data and self-reported historical weights were collected at enrollment. Patients received standard disease treatment strategies, and were systematically followed for disease progression, re-treatment, and death. Single nucleotide polymorphisms (SNPs) were genotyped as part of a custom Illumina iSelect panel. The most prevalent homozygous genotype was used as the reference group, and each SNP was modeled as having a log-additive effect in the regression model. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for the association of the obesity measures and SNPs with outcome, adjusted for treatment class and subtype specific prognostic factors (IPI, FLIPI). Results. For DLBCL patients (median age 63 years, range 18–92) the median follow-up was 47 months (range 0–101); 58% had an IPI 0–1 risk disease; and 87% received immunochemotherapy. For FL patients (median age 60 years, range 25–94), the median follow-up was 60 months (range 11–110); 24% had FLIPI score 3–5; and main initial treatments were observation (32%), rituximab (R)-monotherapy (12%), CVP +/−R (19%), and anthracycline +/−R (22%). The main results for BMI and prognosis are reported in the Table. For DLBCL, obese patients at diagnosis had better EFS and OS; this association was weaker for BMI at age 50 and 35 years. In contrast, for FL, overweight and obese patients at diagnosis had a poorer EFS and OS, and this was also observed for BMIs two years before diagnosis and at ages 50 and 35 years. In FL, the LEP SNP rs2167270 was associated with inferior EFS (HR=1.25; 95%CI 1.05–1.49) and OS (HR=1.28; 95%CI 0.90–1.83). The NPYSNP rs16147 was associated with inferior FL OS (HR=1.50; 95%CI 1.03–2.17) but was not associated with EFS. None of the energy balance and metabolism SNPs were associated with DLBCL EFS or OS. Conclusions. Higher BMI prior to and at diagnosis, as well as SNPs in LEP and NPY,were significantly associated with FL prognosis, with inferior outcomes in overweight and obese patients. These novel findings in the modern treatment era suggest an important role of obesity pathways in FL prognosis. In DLBCL, we confirm the recent findings of improved survival in DLBCL in obese patients, and extend this to the modern treatment era and BMI earlier in life. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 1669 Poster Board I-695 Background The addition of rituximab to chemotherapy significantly improved the results of therapy in aggressive non-Hodgkin's B cell lymphoma (NHL). However, significant number of the patients relapse following initial therapy. Lenalidomide was shown to have significant single agent activity in relapsed aggressive B cell lymphoma (J Clin Oncol 26:4952-7, 2008) however the safety in combination with standard first line immunochemotherapy is unknown. We initiated a phase I/II trial of R2-CHOP (cyclophosphamide, vincristine, doxorubicin, prednisone rituximab and lenalidomide) to establish the safety and efficacy of this therapy in the treatment of patients with newly diagnosed aggressive B cell NHL. Herein, we report the results of phase I portion of this study. Methods A phase I study was designed to define the maximum tolerated dose (MTD) of lenalidomide administered on days 1-10 with R-CHOP chemotherapy (rituximab 375 mg/m2, cyclophosphamide 750 mg/m2, doxorubicin 50mg/m2, vincristine 1.4 mg/m2, all on day 1, prednisone 100 mg/m2 days 1-5 of 21 day cycle) utilizing 3+3 dose escalation design. Lenalidomide dose escalation levels were 15 mg, 20 mg and 25 mg. All patients received 6 mg pegfilgrastim injection on day 2. Dose limiting toxicity (DLT) was defined as any grade 3 or more non-hematological toxicity or a hematological toxicity requiring a delay of the next cycle of chemotherapy due to cytopenia. The latter criterion was to ensure maintenance of the dose intensity and schedule of RCHOP; a potentially curative therapy in this setting. Eligible patients were adults newly diagnosed with CD20 positive diffuse large cell or follicular grade III B cell lymphoma, ECOG PS 0-2 and good organ function. There was no upper age restriction to participate in this study. Results Twelve patients were enrolled in phase I of this study. The median age was 69 years (range, 49-82) and 58% (7/12) of patients were males. Ten patients (83%) had DLBCL and two (17%) patients had follicular grade 3B lymphoma. International prognostic index was intermediate, high- intermediate and high in 6, 4 and 2 patients respectively. Patients distribution by lenalidomide dose was: 3 patients received 15 mg/day, 3 received 20 mg/day and 6 received 25 mg/day on days 1-10. Non-hematological toxicities included: grade 3 toxicity - neuropathy in one patient (8.3%), grade 2 toxicities were: infection in 17% (2/12) patients (skin in one patient, otitis media, and urinary tract infection in one patient); nausea 8% (1/12), rash 8% (1/12) and alopecia 41% (5/12). The most common toxicity to R2-CHOP was myelosuppresion. Grade 3 and 4 neutropenia occurred in 17% (2/12) and 41% (5/12) of patients, respectively. The neutropenia was of short duration, and no patients developed neutropenic complications. Grade 3 thrombocytopenia was seen in 8% (1/12). Most importantly, there were no delays in chemotherapy due to cytopenias. No DLT was seen. The 25 mg/day days 1-10 dose of lenalidomide was taken forward to an ongoing phase 2 trial. Conclusion Lenalidomide at a dose of 25 mg/day for days 1- 10 combined with R-CHOP chemotherapy is well tolerated. The addition of lenalidomide did not affect hematological recovery and did not result in treatment delays. This dose and schedule is now being evaluated in the phase II part of the trial. Disclosures Zent: Genentech, Bayer, Genzyme, Novartis: Research Funding. Witzig:Novartis: Research Funding.