Habermann, Thomas M.

Abstract Background: Non-Hodgkin lymphoma (NHL) is a malignancy of lymphocytes, and may develop in the setting of inflammation and immune dysfunction. Small scale evaluations have suggested that common genetic variation in candidate genes related to immune function may predispose to the development of NHL. Here we report a comprehensive analysis of variants within genes associated with immunity and inflammation and risk of NHL. Methods: We used ParAllele’s Immune and Inflammation panel of 9,412 single nucleotide polymorphisms (SNPs) from 1,450 immune/inflammation genes as a discovery tool in a clinic-based study of 458 NHL cases and 484 frequency matched controls seen at the Mayo Clinic from 2002–2005. The panel included 537 coding non-synonymous SNPs (nsSNPs), with the remainder of the SNPs selected as tags from HapMap (tagSNPs) to provide coverage of the candidate genes (r2 = 0.8 and minor allele frequency >0.05). To assess the association of individual SNPs with risk of NHL, we calculated Odds Ratios (ORs) and 95% confidence intervals, adjusted for age and gender. The most prevalent homozygous genotype was used as the reference group, and each polymorphism was modeled individually as having a log-additive effect in the regression model. Associations between haplotypes from each gene and the risk of NHL were calculated using a score test implemented in HAPLO.SCORE. We also modeled the main effects for all independent (r2 <0.25) SNPs from a gene in a multivariate logistic regression model. Results: The mean age at diagnosis was 60 years for cases and 58% were male; in controls the mean age at enrollment was 61.6 years and 55% were male. In the gene analyses, the strongest findings (p≤0.001 from multiple SNP logistic regression or haplotype analysis) were for cAMP responsive element binding protein 1 (CREB1; p=0.0004), fibrinogen alpha chain (FGA; p=0.0006), TNF receptor-associated factor 1 (TRAF1; p=0.001), dual specificity phosphatase 2 (DUSP2; p=0.001), and fibrinogen gamma chain (FGG; p=0.001). In the nsSNP analyses, the strongest findings (p≤0.01) were for integrin β3 (ITGB3) L59P (OR=0.64, 0.50–0.83), Beta-1,3-N-acetylglucosaminyltransferase 3 (B3GNT3) H328R (OR=0.72, 0.57–0.91), transporter 2, ATP-binding cassette (TAP2) T665A (OR=1.32, 1.07–1.63), HLA-B associated transcript 2 (BAT2) V1895L (OR=0.60, 0.42–0.85), and complement component 7 (C7) T587P (OR=1.39, 1.07–1.80). Conclusions. Our results suggest that genetic variability in genes associated with antigen processing (CREB1 and TAP2), lymphocyte trafficking (B3GNT3), immune activation (TRAF1, BAT2), complement and coagulation pathways (FGA, FGG, ITGB3, C7), and MAPK signaling (DUSP2) may be important in the etiology of NHL, and should be pursued in replication studies.

Abstract Absolute lymphocyte count (ALC) post-autologous stem cell transplantation is an independent predictor for survival in Hodgkin’s Disease (HD). Lymphopenia at diagnosis is associated with worse prognosis in patients with newly diagnosed HD. The role of ALC recovery during standard chemotherapy for HD is unknown. We analyzed all patients managed for HD at the Mayo Clinic from 1986 to 2003. Of the 141 consecutive patients, two patients were excluded due to missing ALC data. Of the 139 patients, 63 patients were females and 76 males. The median age of patients at diagnosis was 31 years (range 6–75 years). 118 (85%) patients presented with nodular sclerosis HD, 10 (7%) with mixed cellularity, 2 (1%) with lymphocyte predominance, 1(1%) with lymphocyte depletion, 4 (3%) with lymphocyte predominant (nodular variant), and 4 (3%) unclassified. Frontline chemotherapy included ABVD (N = 79), MOPP-ABV (N = 47), COPP-ABV (N = 8), BEACOPP (N = 3), and Stanford V (N =2). The median number of cycles was 6 (range: 2–10). The median follow-up for the cohort was 62 months (range: 4–221 months). The ALC recovery was analyzed during the first 4 cycles as 90% of the patients received at least 4 cycles of therapy. Patients with an ALC ≥ 1.3 x 109/l at any time point within the first four cycles of chemotherapy (N = 93) demonstrated improved overall survival (OS) and progression-free survival (PFS) compared to patients with an ALC < 1.3 x 109/L at all time points within the first four cycles of chemotherapy (N =46) (10 years OS and PFS: 91% vs 51%, p < 0.0001; 85% vs 52%, p < 0.0001, respectively). Both groups were balanced for the Hasenclever Index: albumin < 4g/dl (p = 0.1), hemoglobin < 10.5 g/dl (p = 0.46), male gender (p =0.21), age ≥ 45 years (p = 0.06), stage IV disease (p = 0.68), leukocytosis ≥ 15 x 109/L (p = 0.58), and lymphopenia < 600 cell/ml (p = 0.211). Multivariate analysis demonstrated ALC recovery to be independent predictor of OS and PFS when compared to the Hasenclever index. These data suggest a critical role of lymphocyte (immune) recovery during standard chemotherapy in HD.

Abstract E1496 is a phase III trial designed to evaluate the ability of 2 years (yr) of maintenance rituximab (MR) to prolong progression-free survival (PFS) after CVP (cyclophosphamide 1 G/m2 day [d] 1, vincristine 1.4 mg/m2 [max = 2 mg] d 1, prednisone 100 mg/m2 d 1–5) chemotherapy in stage III–IV follicular grade 1 and 2 and small lymphocytic lymphoma. After CVP treatment to maximum response, (6–8 cycles), stable and responding patients (pt) were randomized to MR (375 mg/m2 weekly x 4) every 6 months x 4 or observation (OBS). Stratification factors included histology, response and residual disease after CVP. With 3-yr median follow-up, survivals (from time of randomization, one-sided logrank p values) for all pt (n=304) favored MR for PFS (p = 3 x 10–8; hazard rate {HR} = 0.38 [0.28;0.54, 95% confidence intervals]) and OS (p = 0.09; HR = 0.66 [0.36–1.22]). Because the large majority of pt have FL and because rituximab efficacy is notably greater in FL, we focused in this report on the 237 FL pt. Median age was 58 yr, 65% were stage IV, 64% had marrow disease, 64% had high tumor burden and 37% had high-risk disease by the follicular lymphoma prognostic index. PFS after randomization was significantly longer for MR vs OBS (p = 3 x 10-7; HR = 0.39 [0.27;0.57]). The estimated PFS at 4 yr (~4.5 yr after start of treatment) was 56% for MR vs 33% for OBS. Differences in PFS were significant within the predefined strata and the differences were most significant in favor of MR for pt with high initial tumor burden and minimal residual disease after CVP. Overall survival was superior for MR (p = 0.03; HR = 0.51 [0.25;1.04]. Estimated OS at 4 yr (~4.5 years after start of treatment) was 88% for MR vs 72% for OBS. Of 33 deaths, 21 occurred on the OBS arm. These data demonstrate that maintenance rituximab not only significantly delays disease progression in FL compared with OBS but that a substantial proportion of patients treated with MR remain disease-free at 4 years after the completion of CVP. These are the first data to strongly suggest a survival benefit with a therapy that includes rituximab and CVP and the first to strongly suggest a survival benefit with maintenance rituximab in FL.

Abstract Intravascular lymphoma is a rare subtype of extranodal DLBCL characterized by the proliferation of malignant B-cells within the lumina of blood vessels. Organ involvement is variable and diffuse. Making the diagnosis can be challenging with symptoms persisting for months prior to definitive diagnosis. Treatment to date with standard anthracycline containing chemotherapy regimens has been disappointing with variable response rates, high relapse rates, and median survival times typically measured in months. We report diagnostic, treatment, and follow-up information regarding a group of patients with intravascular lymphoma evaluated at the Mayo Clinic with special attention to those receiving rituximab and/or high dose chemotherapy with or without peripheral blood autologous stem cell rescue. Methods: The medical records of patients with intravascular lymphoma seen at the Mayo Clinic between January 1970 and May 2005 were reviewed. Patients were included if they had evidence of intravascular lymphoma at the time of diagnosis of lymphoma. Pathologic specimens were reviewed for confirmation of diagnosis. Results: Twenty patients with a diagnosis of intravascular lymphoma were identified. Their median age was 66.5 years. Thirteen (65%) had B symptoms at the time of diagnosis and 13 had a performance status ≥ 3. Nine (45%) had an IPI ≥ 4. The median time to diagnosis from the onset of symptoms was 5.5 months. All had stage IV disease with biopsy proven involvement of at least one organ. The sites of disease involvement were CNS (10), marrow (7), lung (5), adrenal (3), kidney (2), lymph node, seminal vesicle, and skin (1). Two patients had involvement of three organs, six had involvement of two organs, and twelve had involvement of one organ. Nineteen patients received chemotherapy: ProMACE/CytaBOM (3), CHOP (6), RCHOP (6), DHAP (1), high dose methotrexate (1), methylprednisolone, nitrogen mustard, rituximab (1), and hyperCVAD (1). Three patients underwent peripheral blood autologous stem cell rescue after conditioning with BEAM. With a median follow-up of 60 months for all patients, the median overall survival was 8 months. No difference in outcome was seen with regard to site of organ involvement, number of organs involved, presence of B symptoms, or IPI. With a median follow-up for those receiving rituximab of 26 months, the median survival has not yet been reached while the median survival for those receiving non-rituximab containing regimens was 6.5 months. Similarly, with a median follow-up for those receiving high dose chemotherapy (hyperCVAD or BEAM) of 9.3 months, the median survival has not yet been reached while the median survival for those not receiving high dose therapy was 7 months. Conclusion: Intravascular lymphoma is a unique and aggressive subtype of DLBCL. The clinical presentation and sites of organ involvement are variable and the time from onset of symptoms to diagnosis can be prolonged. Standard chemotherapeutic treatment leads to poor outcomes. However, survival may be improved upon with newer strategies such as the use of rituximab and/or high dose chemotherapy with or without peripheral blood autologous stem cell rescue.

Abstract Background: Castleman Disease (angiofollicular hyperplasia) is a rare, lymphoproliferative disease. There has been no large study describing the natural history of this disease. Hypothesis: A retrospective analysis of clinical, pathologic, and laboratory factors predictive of outcome should be identifiable. Methods: During the period from 3/30/48 to 6/18/2002, 114 patients with Castleman Disease were seen at the Mayo Clinic (Rochester, 56; Jacksonville, 19; Arizona, 13) and at the University of Nebraska (26). Pathology, laboratory and clinical characteristics analyzed included: the presence of unicentric or multicentric disease, the pathologic variant (hyaline vascular versus plasma cell variant), co-existing POEMS syndrome, age, serum albumin, alkaline phosphatase, AST, sedimentation rate, the presence of cytopenias, organomegaly (hepatomegaly or splenomegaly), papilledema, peripheral neuropathy, sclerotic bone lesions, renal disease, B-symptoms or respiratory symptoms. The impact of these variables on overall survival from time of diagnosis was evaluated using univariate analyses, where their significance was determined based on the logrank statistic. To derive the multivariable model, the score-based model-building method was used. Based on this approach, a 3-variable model was designed, adjusting for age at diagnosis. Patients were then assigned a risk score corresponding to how many of these risk factors they possessed. A final proportional hazards model was constructed based on this risk score. Results: The median age at diagnosis was 43 (range: 5 – 78), and 48% of patients were male. Fifty-five patients had multicentric disease. Median follow-up of living patients was 5.8 years (range: 0.02 – 27). On univariate analysis, factors that predicted for overall survival included: age at diagnosis, presence of multicentric disease, presence of a monoclonal protein in the urine, co-existing POEMS syndrome, serum albumin, presence of cytopenias, organomegaly, neuropathy, thrombocytosis, and respiratory symptoms. The final multivariable model included 98 patients. Adjusting for age, the model included organomegaly, respiratory symptoms, and thrombocytosis. Patients were assigned 1 point for each risk factor they possessed based on clinical relevance and similarity of the hazard ratios for each of these 3 variables (ranging from 3.1 to 4). A final prognostic survival model was constructed using this assigned risk score. These scores were collapsed further based on observed similarities (0 factors vs. 1 or more factors). This final model yielded a hazards ratio of 5.5 (95% CI 2.3–13.4). The 10 year survival rates were 80% (95% CI: 65–98%) and 41% (95% CI: 28–59%) for the 0 factor and 1+ factor groups, respectively. The 20 year survival rates were 71% (95% CI: 52–87%) and 31% (95% CI: 19–51%), respectively. Conclusion: The most distinguishing prognostic clinical, laboratory, and pathological characteristics of Castleman’s Disease are orgnaomegaly, respiratory symptoms, and thrombocytosis. This prognostic scoring system should aid in individual cases and in assessing results of therapeutic interventions.

Abstract INTRODUCTION: Adult mature T- and NK-cell neoplasms are a heterogeneous group of aggressive lymphomas comprising approximately 10% to 20% of all non-Hodgkin lymphomas (NHL) with an estimated 5-year overall survival of 40%. Staging and treatment strategies are guided by malignant involvement on PET/CT scan and bone marrow (BM) biopsy. The Lugano Criteria, established in 2014, suggested that focal FDG uptake within the bone marrow was highly sensitive for both Hodgkin (HL) and diffuse large B-cell lymphoma (DLBCL) potentially obviating the need for a bone marrow biopsy if no lesions were seen. Limited data exist regarding the sensitivity of PET for BM involvement in T-cell lymphoma. This study compares PET/CT scans and repeat BM biopsy in patients who have undergone treatment for peripheral T-cell lymphomas (PTCL) by evaluating BM avidity on PET scans. METHODS: This is a single institution study using the Mayo Clinic Lymphoma Database between January 1, 2001 and January 1, 2015. We retrospectively identified all patients with a diagnosis of PTCL, biopsy proven BM involvement at diagnosis, and a concomitant PET for staging. Patients were then reviewed to assess completion of induction therapy and availability of both PET/CT and bone marrow results post-therapy. Evaluation for concordance and discordant BM involvement were then determined using BM biopsy as the gold standard. RESULTS: Sixteen patients had both PET/CT and BM biopsy after completing induction therapy. Median age at diagnosis was 63 years (range 34-72) and 69% were male. PTCL subtype was peripheral T-cell lymphoma, not otherwise specified in seven patients; ALK negative anaplastic large cell lymphoma in one patient; and angioimmunoblastic in 8 patients. Pre-treatment PET/CT scans demonstrated eight patients (50%) with false negative scans. Post-treatment biopsy results demonstrated that ten (62.5%) had biopsy proven residual bone marrow involvement after induction. Eight patients (50%) were found to have BM biopsy proven disease with a negative PET scan. Two patients (12.5%) had both positive BM biopsy and PET scans; 5 patients (31.3%) had negative BM biopsies and PET scans. One patient (6.25%) had a negative BM biopsy, but had a PET scan that revealed positive disease. This patient was considered to have had a false positive PET scan and indeed has remained in remission since April 2009 without any further relapse or treatment. Sensitivity of PET for BM involvement was very poor at 20% (2/10) with a specificity of 50% (2/4) (Table 1 and 2). CONCLUSIONS: This study in PTCL indicates that PET scans at the completion of therapy have a 50% false negative rate. These patients should not be assumed to have negative bone marrow involvement based solely on PET/CT scans. A bone marrow biopsy at the end of therapy is necessary in PTCL patients to confirm complete response. Table 1. Bone Marrow Involvement Pre-Therapy PET Scan Imaging PET Negative PET Positive Total Patients Bone Marrow Negative NA NA NA Bone Marrow Positive 8 8 16 Total Patients 8 (50%) 8 (50%) 16 Abbreviations: NA, not applicable. The study defined that all patients had to have a positive bone marrow at baseline to be eligible for the study. Table 2. Bone Marrow Involvement PET Negative PET Positive Total Patients Bone Marrow Negative 4 2 6 (37.5%) Bone Marrow Positive 8 2 10 (62.5%) Total Patients 12 (75%) 4 (25%) 16 Table 1 and 2. Involvement of bone marrow with peripheral T-cell lymphoma based on evaluation by PET scans versus bone marrow biopsy. Disclosures Maurer: Kite Pharma: Research Funding.

Abstract Background: Recent literature suggests that statins may have anticancer potential. This effect is thought to be mediated through 2 primary mechanisms - impairment of protein prenylation and interference with the formation of cholesterol-rich lipid microdomains, or “lipid rafts” within the cell membrane. Both of these processes are critical for signaling activity of numerous proteins important for lymphomagenesis and tumor survival. Recent data, however, suggest that statin use may directly inhibit rituximab binding to CD20 and therefore rituximab efficacy. These findings raised significant concerns about statin use during rituximab treatment. Here we report on statin use and clinical outcome in a cohort of FL and DLBCL treated patients, most of whom were treated with rituximab containing regimens. Methods: 293 newly diagnosed FL patients and 228 newly diagnosed DLBCL patients were prospectively enrolled in our Lymphoma SPORE registry from 9/2002 through 6/2007. Pathology was centrally reviewed. All patients were followed for retreatment, progression-free and overall survival. Statin use at the time of diagnosis and time of initial treatment was abstracted from the medical record. An event was defined by disease progression, retreatment, or death due to any cause. Results: 19% of FL patients and 22% of DLBCL patients were on statins at diagnosis; 16% and 19% were on statins during treatment, respectively. Initial therapy for the FL patients was observation (40%), R-CHOP (19%), R-CVP (12%), rituximab alone (8%), CVP (7%), RT (6%), and other (8%). All DLBCL patients received rituximab with CHOP or a CHOP-like regimen. At a median follow-up of 36 months (range 3–73), 109 (37%) and 65 (29%) of FL and DLBCL patients had an event; 19 (6%) and 46 (20%) of FL and DLBCL patients died, respectively. After adjusting for FLIPI, grade, and initial therapy type, statin use at diagnosis was associated with better event-free survival (HR = 0.57, 95% CI: 0.34–0.95, p=0.03) in FL patients. Statin use during treatment in FL patients was also associated with better event-free survival, though not statistically significant (HR = 0.67, 95% CI: 0.39–1.16, p=0.15). The improvement in EFS for FL patients was consistent across initial therapies, including observation. Statin use was not associated with IPI-adjusted overall survival or event-free survival in DLBCL (all p > 0.50). Conclusions: Statin therapy does not appear to be associated with inferior clinical outcome in DLBCL treated with rituximab and CHOP or CHOP-like therapy. Therefore direct inhibition of rituximab binding to CD20 may have limited clinical significance or/and may be overcome by inhibitory impact of statins on cell signaling. The latter possibility is supported by our observation that statin use is associated with improved event-free survival in follicular lymphoma. Figure Figure Figure Figure

Abstract Background: Inhibitors of HMG-CoA reductase (“statins”) are effective in reducing the risk of cardiovascular disease. Preclinical data from rodents suggested that they may increase the incidence of some cancers, including lymphoma. However, monitoring of randomized trials in humans have generally found decreased cancer risks, and these findings have been supported by a growing number of observational studies, including three recent reports of a protective association in NHL. The suggested anti-carcinogenic mechanisms for statins include their impact on inflammatory (including a shift from a Th1 to Th2 profile) and angiogenesis pathways, as well as the induction of apoptosis by modulation of signaling pathways, all of which are of biologic relevance in NHL. Methods: We evaluated the history of statin use and risk of NHL in a clinic-based study of 243 newly diagnosed NHL cases and 499 frequency matched controls enrolled at the Mayo Clinic from 2002-2005. Risk factor data were collected using self-administered questionnaires, and included history of use of cholesterol lowering drugs two or more years before diagnosis (for cases) or enrollment (for controls); specific drug names were not available. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI), adjusting for age, gender, and residence. NHL subtypes were centrally reviewed, and subtype-specific risks were estimated using polychotomous logistic regression. Results. The mean age at diagnosis was 59.5 years for cases and 55% were men; among controls, the mean age at enrollment was 61.8 years and 54% were men. Twenty-one percent of the cases reported ever using statins compared to 30% of the controls, supporting a lower risk of NHL for ever users (OR=0.69; 95% CI 0.47–1.00). The lowest risk was seen for the longest users; i.e., compared to never users, person who had 10 or more years of use had the greatest reduction in risk (OR=0.52; 95% CI 0.24–1.10). A history of high cholesterol was also inversely associated with risk of NHL (OR=0.72; 95% CI 0.55–0.93). However, the association for the type of treatment for cholesterol lowering varied. Those who were medically treated had inverse association with risk of NHL (OR=0.63; 95% CI 0.46–0.86), while the no treatment and dietary change only groups were found to have no association with risk. The reduction in NHL risk with medical treatment was specific to statin use, as the use of other cholesterol lowering drugs was not associated with risk (OR=1.13; 95% CI 0.50–2.57). These results were not confounded by education, family history of NHL, body mass index, cigarette smoking or alcohol use. In subtype analysis, the inverse association was seen for diffuse large B-cell lymphoma (OR=0.27; 95% CI 0.08–0.90), but not for CLL/SLL or follicular NHL. Conclusions. Statin use was associated with a lower risk of developing NHL, particular diffuse large B-Cell lymphoma.

Abstract Background: Patients with diffuse large B-cell lymphoma (DLBCL) not cured by first line R-CHOP chemotherapy or second line high-dose chemotherapy with autologous stem cell rescue have a poor prognosis and represent a clear unmet medical need. Lenalidomide (Revlimid®), an immunomodulatory drug, has activity in hematological malignancies including relapsed/refractory multiple myeloma, chronic lymphocytic leukemia and cutaneous T-cell lymphoma. Aim: To determine the activity and safety of lenalidomide monotherapy in relapsed/refractory DLBCL. Methods: Patients with relapsed/refractory DLBCL with measurable disease after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1–21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Univariate analyses using Fisher’s exact test was conducted to investigate and characterize associations of prognostic variables with response. Results: Twenty-six patients with DLBCL lymphoma were enrolled. The median age was 66 (45–86) and 13 were female. Median time from diagnosis to lenalidomide was 2.4 (0.5–12) years and median number of prior treatment regimens was 3 (1–6). Three patients (12%) exhibited an objective complete response (1 complete response (CR) and 2 complete responses unconfirmed (CRu)). Two patients had a partial response (PR) for an overall response rate of 19% and 7 had stable disease (SD). Response to lenalidomide was associated with low disease burden (33% for < 50 cm2v 0% for ≥ 50 cm2, P=0.06) and longer time from rituximab to lenalidomide treatment (33% for ≥ 230 days v 0% for < 230 days, P=0.05). Patients with favorable values for both these prognostic factors (N = 10) had a 50% response rate [RR] (30% CR/CRu RR) compared with a 0% RR for patients with unfavorable values (N = 16; P < 0.004) and a progression free survival (ongoing) of 7.4 months v 1.9 months. Although there were no responses in the poor prognosis group, 4 patients exhibited stable disease with an ongoing median PFS of > 4.2 months (> 3.6 - > 6.2). Eight patients (31%) required at least one dose reduction with a median time to first dose reduction of 1.8 months (0.4–2.9). One patient each (4%) had Grade 4 anemia, cauda equinine syndrome, febrile neutropenia, intermittent rash, lymphopenia, neutropenia, pneumonitis and thrombocytopenia. Most common Grade 3 adverse events were neutropenia (19%), thrombocytopenia (15%) and leukopenia (12%). Conclusion: The prognostic factors of tumor burden and time from last dose of rituximab appear to identify relapsed/refractory DLBCL patients with a high likelihood of response to lenalidomide oral monotherapy.

Abstract Background: A significant percentage of DLBCL patients present with a composite histology, often seen as a node containing both follicular lymphoma and DLBCL or DLBCL in the node and discordant indolent lymphoma in the bone marrow. Literature from the pre-rituximab era suggests DLBCL patients with transformed lymphoma or composite histology have worse outcome than de novo DLBCL. Here we report on early events in a cohort of R-CHOP treated patients. Goal: To determine whether patients with composite lymphoma have an inferior event free survival (EFS) and overall survival (OS) compared to de novo diffuse large B-cell lymphoma when treated with R-CHOP. Methods: Newly diagnosed patients treated with an R-CHOP containing regimen were prospectively enrolled in our Lymphoma SPORE registry from 9/2002 through 6/2007. Pathology was centrally reviewed. All patients were followed for retreatment, disease progression, and death. Results: 401 DLBCL patients were enrolled; 14% (57/401) had a composite histology. 33 patients had DLBCL and another histology, predominantly follicular lymphoma (n=29), in the same node. 20 patients had a non-DLBCL histology in a distinct location from the DLBCL; this was primarily indolent lymphoma in the bone marrow (n=15). 4 patients had both. 19% (75/401) of patients died during follow-up and 30% (121/401) had an event (death due to any cause, progression, or retreatment). Median follow-up for living patients was 34 months (range, 5–73). Composite DLBCL patients had higher event-free (3 year EFS = 79%) and overall (3 year OS = 93%) survival then de novo DLBCL (3 year OS = 66%, 3 year EFS 79%), p=0.05 and p=0.005 respectively. These differences remained statistically significant after adjusting for the International Prognostic Index (IPI): EFS HR = 0.53, 95% CI: 0.29–0.97, p=0.02; OS HR=0.28, 95% CI: 0.10–0.76, p=0.002. OS and EFS for composite DLBCL more closely resembled R-CHOP treated grade III follicular lymphoma (A,B) from the same cohort (3 year EFS = 81%, 3 year OS = 93%). Improved outcome for composite DLBCL was consistent whether the additional histology was in the same node or distinct from the DLBCL. Conclusions: R-CHOP treated DLBCL patients with indolent discordant bone marrow involvement or other composite histology have improved early OS and EFS compared to de novo DLBCL. Further follow-up is needed to assess the long-term prognosis of composite DLBCL in the rituximab era. Histology N Age > 60 Stage III/IV LDH > ULN PS > 1 >2 EN Sites 3 YR EFS 3 YR OS * Denotes statistically significant difference at p=0.05 de novo DLBCL 344 58% 56% 56% 17% 22% 66% 78% Composite DLBCL 57 65% 77%* 34%* 18% 32% 79%* 93%* Figure Figure