Macon, William R.

Abstract Abstract 443 Background: MYC translocations have been reported to have inferior outcome in aggressive non-Hodgkin lymphomas. Here we present MYC translocation prevalence and outcome from two cohorts of newly diagnosed diffuse large B-cell lymphoma (DLBCL) patients treated in the chemotherapy (C) and immunochemotherapy (IC) eras. Methods: Tissue microarrays were created from 302 newly diagnosed DLBCL patients evaluated at the Mayo Clinic with availabel paraffin tissue. 233 DLBCL patients first diagnosed from March 1986-July 2001 were retrospectively identified based on a diagnosis of DLBCL and treatment with anthracycline-based chemotherapy. 69 DLBCL patients diagnosed from March 2002-October 2005 and treated with immunochemotherapy were prospectively enrolled in the University of Iowa / Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource. Central pathology review was performed on all samples to confirm the diagnosis of DLBCL. Interphase FISH was performed using a breakapart strategy for MYC and BCL6 gene regions and a dual fusion strategy for t(14;18)(IGH&/BCL2). Results: Chemotherapy (C) era patients were primarily treated with CHOP (88%); immunochemotherapy (IC) era patients were all treated with an R-CHOP based regimen. The median age at diagnosis was 65 years (range, 22-92) for C patients and 65 years (range, 20-82) for IC patients. Median follow-up for C patients was 11.3 years (range, 2.7-21.3) with 145 (62%) deaths; for IC patients, the median follow-up was 5.0 years (range, 2.1-6.4) with 17 deaths (25%). FISH was successful in 195 of 302 patients (65%). MYC translocations were identified in 6 of 141 C patients (4%) and 3 of 54 IC patients (6%). MYC translocations were associated with inferior overall survival in the C patients (p=0.001), the IC patients (p=0.04), and in the combined group (p≤0.001). Median survival of patients with MYC translocations was 19 months and 16 months for C and IC respectively, compared to 112 months (C) and unreached (IC) for DLBCL patients without MYC translocations. 4 of the 9 MYC translocation patients had a double hit (2 with both MYC and BCL2 translocations and 2 with translocations of MYC, BCL2, and BCL6). Associations of MYC and outcome remained significant in all patients after adjusting for treatment and IPI (p<0.05). Conclusions: MYC translocations are present in approximately 5% of DLBCL patients and are associated with poor outcome in patients treated with C or IC. New treatment approaches are needed for DLBCL patients with MYC translocations. Disclosures: No relevant conflicts of interest to declare.

Abstract Abstract 4637 Primary central nervous system lymphoma (PCNSL) is an aggressive form of extra-nodal, high-grade, non-Hodgkin B-cell neoplasm. It originates in the brain, leptomeninges, spinal cord or eyes and typically remains confined to the CNS. Further immunophenotypic characterization has revealed that these tumors have overlapping features of germinal center and activated B-cell differentiation. Although the cells of origin are lymphocytes, PCNSL should be considered a brain tumor because its therapeutic challenges resemble those of other brain tumors. Regarding the molecular pathogenesis of PCNSL, there is significantly less information in comparison with systemic lymphomas. The aim of this study was to perform a comprehensive high-resolution genomic analysis in a cohort of PCNSL cases to better characterize the disease at chromosomal and gene level. Copy-number abnormalities were analyzed in seven PCNSL by array-based comparative genomic hybridization (aCGH) using SurePrint G3 (1 million probes, ∼4 Kb resolution) microarray (Agilent). Overall, PCNSL cases were characterized by highly complex genomes with a median of 23 copy-number abnormalities per patient (range 16-49). The whole genomic regions affected in abnormalities correspond to areas between 3% and 29% of the human genome. Globally, 43 chromosomal regions were affected in a recurrent fashion (24 areas involved in recurrent deletions and 19 in copy-number gains). Gain of 12q12-q24.33 and losses of 9p21.3 and 6q were the most common abnormalities found in 71% patients each (5 out of 7). There was not a unique deleted region on 6q to all patients, with 6q14.1-q14.3, 6q16.3-q22.2 and 6q25.3-q26 losses being found in 4 out of 5 cases with 6q deletions. None of these regions include PTPRK, which has been previously proposed as a potential modulator of PCNSL progression. CDKN2A was the sole gene included in all cases with 9p21.3, being biallelically deleted in two out of 5 cases. Minimal deleted genes were also delineated in 3p21.1 (minimal affected area of 0.03Mb) and 3q26.32 (0.27Mb) in 44% of cases each. Those regions included PRKCD (inhibits B-cell growth through transcriptional regulation of IL-6) and TBL1XR1 (corepressor of nuclear hormone receptor), respectively. Overall, a total of 22 genes were included in homozygous deletions in at least one case. Besides CDKN2A (cell cycle), other genes of interest associated with the development and activation of T cells (TOX, CD58) were biallelically affected. Focal monoallelic deletions affecting negative regulators of the NFkB signaling pathway (MAP4K1, TANK, TAX1BP1, TRIB3), cell cycle (RB1) and immune-cell regulation (SIRPB1, CBLB, NFATC2) were also identified. Of interest, no copy-number abnormalities were identified affecting TP53 in any patient. Several chromosomal breakpoints were identified inside genes that encodes transcription factors previously identified as being part of fusion protein in other hematological malignancies (FOXP1, ETV6 and NCOA2) thus suggesting the potential existence of fusion proteins including these genes. Cytogenetic and genetic approaches are being currently used to validate this hypothesis. This is the first study characterizing a cohort of PCNSL cases by using this comprehensive high-resolution approach. Regarding the small number of cases analyzed so far, we can confirm the existence of a highly complex genome, mainly characterized by abnormalities affecting a plethora of genes involved in lymphocyte development, activation and NF-kB signaling pathways regulation. Molecular analyses are ongoing to validate these findings in a larger cohort of PCNSL patients. Disclosures: Fonseca: Otsuka: Consultancy; BMS: Consultancy; Amgen: Consultancy; Medtronic : Consultancy; Genzyme: Consultancy.

Abstract Abstract 440 Background: Complement plays a central role in innate immunity, and also functions as a regulator of the overall immune response, including T-cell responses. We recently reported that germline genetic variation in C2, C5, C7 and C9 was associated with risk of developing non-Hodgkin lymphoma (Br J Haematol 2009;145:614). Here we evaluate whether complement genes are associated with event-free survival (EFS) in follicular lymphoma. Methods: We genotyped 166 single nucleotide polymorphisms (SNPs) from 32 complement pathway genes in a prospective cohort study of 115 newly diagnosed follicular lymphoma patients enrolled at the Mayo Clinic from 2002-2005 as part of the Lymphoma SPORE. All patients were systematically followed through 2008 for EFS (defined as disease progression, retreatment, or death due to any cause). Tagging and nsSNPs were selected from HapMap for the genes encoding complement proteins and their key regulators (C1QB, C1QG, C1QR1, C1QTNF7, C1RL, C1S, C2, C3, C3AR1, C4BPA, C4BPB, C5, C5R1, C6, C7, C8B, C9, BF, CFH, CFHL5, CFHR1, CGHR4, CLU, CR1 (CD35), CR2 (CD21), DF, MASP2, MBL2, MCP (CD46), DAF (CD55), CD59 and SERPING1). Cox regression was used to estimate Hazard Ratios (HRs) for individual SNPs with EFS. 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. For gene-level analyses, we used a principal components based gene-level test. All models were adjusted for sex, FLIPI, follicular grade III, and initial treatment. Results. The median age at diagnosis was 61 years (range, 25-85). 57 (50%) of the patients had an event, at a median follow-up of 59 months (range, 33-73) for living patients. In gene-level analyses, CFH (p=0.004), CD55 (p=0.02), CFHR5 (p=0.02) and CFHR1 (p=0.02) were significant at p<0.05, and these genes had noteworthy q-values after consideration of multiple testing (q=0.04 for CFH and q=0.08 for CD55, CFHR5, and CFHR1). For CFH, 2 of the 11 tagSNPs (rs1329423, HR=0.46, p=0.001; and rs3766404, HR=2.0, p=0.003) were significantly associated with EFS, as was the nsSNP rs1065489 (amino acid change E936D: HR=0.39, p=0.004). For CD55, both tagSNPs (rs4844591, HR=0.58, p=0.03; and rs2564978, HR=0.58, p=0.03) were associated with EFS, as were 3 of 5 tagSNPs from CFHR5 (rs3748557, HR=0.52, p=0.03; rs12092294, HR=1.9, p=0.03; and rs6694672, HR=1.9, p=0.03) and the only tagSNP for CFHR1 (rs436719, HR=0.54, p=0.03). Conclusions. Genetic variation in CFH, CD55, CFHR5, and CFHR1 was associated with EFS in follicular lymphoma after adjustment for clinical variables. These genes are part of a gene cluster at 1q32-q32.1 involved in the regulation of C3. CD55 encodes a membrane complement regulatory protein which can allow tumor cells to evade complement attack. These results are being validated in a second set of SPORE patients. Support: P50 CA97274, R01 CA92153. Disclosures: No relevant conflicts of interest to declare.

We report an index case of histiocytic sarcoma arising in a 70-year-old patient with long-standing chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The patient presented in 2017 with painful, enlarging swelling of the left neck. He had remote history of cutaneous squamous cell carcinoma with no sign of recurrence, and his CLL/SLL was thought to be in remission. Computed tomography showed mild splenomegaly and multifocal lymphadenopathy including a 3-cm left neck mass. Biopsy of the left neck mass showed CLL/SLL with associated histiocytic sarcoma. Flow cytometry demonstrated a B cell neoplasm with CLL/SLL phenotype. Despite radiation therapy, he expired 3 months after presentation. Two similar cases (CLL/SLL and histiocytic sarcoma, follicular lymphoma and Langerhans cell sarcoma) from another institution are also illustrated. The pathological features of combined tumors in lymphoid neoplasms, a general framework to the work-up to determine interrelatedness of tumor components, and the clinical relevance are discussed.

AbstractMAPK pathway activation has been recurrently observed in desmoplastic infantile ganglioglioma/astrocytoma (DIG/DIA) with reported disproportionally low mutation allele frequencies relative to the apparent high tumor content, suggesting that MAPK pathway alterations may be subclonal. We sought to expand the number of molecularly profiled cases and investigate if tumor cell composition could account for the observed low mutation allele frequencies. Molecular (targeted neuro-oncology next-generation sequencing/RNA sequencing and OncoScan microarray) and immunohistochemical (CD68-PGM1/CD163/CD14/CD11c/lysozyme/CD3/CD20/CD34/PD-L1) studies were performed in 7 DIG. Activating MAPK pathway alterations were identified in 4 (57%) cases: 3 had a BRAF mutation (V600E/V600D/V600_W604delinsDQTDG, at 8%–27% variant allele frequency) and 1 showed a TPM3-NTRK1 fusion. Copy number changes were infrequent and nonrecurrent. All tumors had at least 30% of cells morphologically and immunophenotypically consistent with microglial/macrophage lineage. Two subtotally resected tumors regrew; 1 was re-excised and received adjuvant treatment (chemotherapy/targeted therapy), with clinical response to targeted therapy only. Even with residual tumor, all patients are alive (median follow-up, 83 months; 19–139). This study further supports DIG as another MAPK pathway-driven neuroepithelial tumor, thus expanding potential treatment options for tumors not amenable to surgical cure, and suggests that DIG is a microglia/macrophage-rich neuroepithelial tumor with frequent low driver mutation allele frequencies.

Background:Predicting early clinical failure in patients with untreated follicular lymphoma (FL) is important but difficult. Lymphoma involvement of extranodal (EN) sites is better detected by FDG‐PET/CT than CT alone, but PET parameters are not part of the usual predictive indices.Aims:We aimed to determine the incidence and patterns of EN and spleen disease, and learn if they were useful in predicting early clinical failure.Methods:PET/CT images from 613 cases of newly diagnosed FL between 2003 – 2016 were retrospectively reviewed for EN and spleen involvement. The location, number, and pattern of EN sites, as well as splenic involvement, were recorded. Associations with outcomes were assessed using event‐free survival (EFS), overall survival (OS), and early clinical failure at 24 months (EFS24).Results:49% (301/613) of patients had PET/CT‐detected EN involvement, and 28% (171/613) had spleen involvement. Presence of ≥2 EN sites, spleen, bone or soft tissue involvement all predicted failure to achieve EFS24. These factors, as well as pattern of bone involvement by imaging, were predictors of EFS on univariate analysis; presence of ≥2 EN sites and bone involvement pattern were also predictive of OS. In a multivariate analysis with FLIPI‐2 factors, spleen involvement, pattern of bone involvement, and soft tissue involvement independently predicted a lower EFS (Table 1). When the multivariate analysis was performed using PRIMA‐PI factors (marrow and B2 M), the presence of ≥2 EN sites was an adverse independent prognostic factor for OS (HR 2.28; 95% CI 1.01–5.18; p = 0.05).Table 1: Extranodal and spleen involvement by PET/CT as predictors of event‐free survival Summary/Conclusion:Baseline PET/CT identifies EN and spleen sites of disease that can predict early clinical failure in FL. These results, when combined with other factors, may better identify high‐risk patients and guide appropriate therapy.imageimage

AbstractPredicting early clinical failure in patients with untreated follicular lymphoma (FL) is important but difficult. This study aimed to determine the incidence and patterns of extranodal (EN) and spleen disease using PET/CT, and assess their utility in predicting early clinical failure. PET/CT images from 613 cases of untreated FL (2003‐2016) were reviewed. The location and number of EN sites, patterns of bone involvement, and splenic involvement were recorded. Outcomes were assessed using event‐free survival (EFS), overall survival (OS), and early clinical failure at 24 months (EFS24). So, 49% (301/613) of patients had PET/CT‐detected EN involvement, and 28% (171/613) had spleen involvement. The presence of ≥2 EN sites, spleen, bone or soft tissue involvement all predicted failure to achieve EFS24. Presence of ≥2 EN sites and bone involvement pattern were also predictive of OS in a univariate analysis. In a multivariate analysis with FLIPI‐2 factors, spleen involvement, pattern of bone involvement, and soft tissue involvement independently predicted a lower EFS (HR 1.49 (1.11‐2.00),P= .007; HR 1.71 (1.10‐2.65),P= .017; and HR 1.67 (1.06‐2.62),P= .026, respectively). When the multivariate analysis was performed using PRIMA‐PI factors (marrow and B2M), the number of EN sites was an independent prognostic factor for inferior OS (HR 2.28;P= .05). Baseline PET/CT identifies EN involvement in nearly half of patients with untreated FL. The presence of ≥2 EN sites, bone, soft tissue, or splenic involvement predicts early clinical failure. These results, when combined with other factors, may better identify high‐risk patients and guide therapy.