Citations

7506 Background: Optimal consolidative therapy for primary central nervous system lymphoma (PCNSL) is not defined. Avoidance of whole brain radiation may reduce risk of neurotoxicity. Non-radiation consolidative options include myeloablative chemotherapy with autologous stem cell transplantation (HDT/ASCT) or non-myeloablative chemotherapy. Methods: This is a randomized phase 2, National Clinical Trials Network study of induction methotrexate (MTX) (8 g/m2 days 1, 15), temozolomide (TMZ) (150-200 mg/m2 D7-11), and rituximab (RTX) (C1 D3, 10, 17, 24 and C2 D3, 10 ) in four 28-day cycles followed by one cycle of cytarabine (ARA-C) (2 g/m2 BID, D1, 2) (MTRA). After induction, patients (pts) received consolidation with thiotepa (5 mg/kg BID, D -5, -4) plus carmustine (400 mg/m2, day -6) and ASCT (Arm A) or one cycle of ARA-C (2 g/m2 BID, D1-4) plus infusional etoposide (40 mg/kg over 96h) (Arm B). Pts were stratified on age and performance status and randomized 1:1 before induction. The primary endpoint was progression-free survival (PFS) from randomization. With 110 pts, there was 84% power to detect an improvement in PFS using a log-rank test (1-sided α= 10%), assuming a median PFS of 3 months for pts who progress during induction, and a median PFS of 2 years (yrs) for Arm B and 4.5 yrs for Arm A consolidation. This report includes the results for the primary endpoint analysis. Results: 113 pts (median age 61 yrs, range 33-75) were randomized (Arm A: 57, Arm B: 56) across 27 centers. 108 eligible pts who received induction therapy were included in the primary endpoint analysis (Arm A: 54, Arm B: 54). 72/108 pts started consolidation and 70/72 completed consolidation per protocol (Arm A: 36, Arm B: 34). With a median follow-up of 3.8 years, median PFS from randomization was 6 yrs (95% CI 3.9-not reached) in Arm A vs 2.4 yrs (95% CI 0.6-not reached) in Arm B (p = 0.02). However, more pts randomized to Arm B went off treatment before consolidation due to progression or death (28% vs 11%, p = 0.05). PFS landmarked at start of consolidation demonstrated a trend for improved PFS favoring Arm A (HR 0.58, 95% CI 0.25-1.36; p = 0.21). Median OS was not reached in either arm, and 3-yr estimates were 83% (95% CI 69-91; Arm A) vs 72% (95% CI 57-82; Arm B). Toxicities were similar between arms with no treatment-related mortality during consolidation. Conclusions: MTRA induction followed by myeloablative consolidation (Arm A) had improved PFS vs MTRA induction followed by non-myeloablative consolidation (Arm B), though more progressions or deaths leading to treatment discontinuation prior to consolidation in Arm B were noted. Both consolidation regimens were well-tolerated with encouraging PFS and OS in newly-diagnosed PCNSL. Support: U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org . Clinical trial information: NCT01511562.

Abstract Context. —Molecular pathology is a rapidly growing area of laboratory medicine in which DNA and RNA are analyzed. The recent introduction of array technology has added another layer of complexity involving massive parallel analysis of multiple genes, transcripts, or proteins. Objective. —As molecular technologies are increasingly implemented in clinical settings, it is important to bring uniformity to the way that test results are reported. Data Sources. —The College of American Pathologists Molecular Pathology Resource Committee members summarize elements that are already common to virtually all molecular pathology reports, as set forth in the College of American Pathologists checklists used in the laboratory accreditation process. Consensus recommendations are proposed to improve report format and content, and areas of controversy are discussed. Resources are cited that promote use of proper gene nomenclature and that describe methods for reporting mutations, translocations, microsatellite instability, and other genetic alterations related to inherited disease, cancer, identity testing, microbiology, and pharmacogenetics. Conclusions. —These resources and recommendations provide a framework for composing patient reports to convey molecular test results and their clinical significance to members of the health care team.

Abstract Diffuse large B-cell lymphoma (DLBCL) is the major type of aggressive B-cell lymphoma. High-grade B-cell lymphoma (HGBCL) with MYC/BCL2 double-hit (DH) represents a distinct entity with dismal prognosis after standard immunochemotherapy in the current WHO lymphoma classification. However, whether TP53 mutation synergizes with MYC abnormalities (MYC rearrangement and/or Myc protein overexpression) contributing to HGBCL-like biology and prognosis is not well investigated. In this study, patients with DLBCL with MYC/TP53 abnormalities demonstrated poor clinical outcome, high-grade morphology, and distinct gene expression signatures. To identify more effective therapies for this distinctive DLBCL subset, novel MYC/TP53/BCL-2–targeted agents were investigated in DLBCL cells with MYC/TP53 dual alterations or HGBCL-MYC/BCL2-DH. A BET inhibitor INCB057643 effectively inhibited cell viability and induced apoptosis in DLBCL/HGBCL cells regardless of MYC/BCL2/TP53 status. Combining INCB057643 with a MDM2-p53 inhibitor DS3032b significantly enhanced the cytotoxic effects in HGBCL-DH without TP53 mutation, while combining with the BCL-2 inhibitor venetoclax displayed potent therapeutic synergy in DLBCL/HGBCL cells with and without concurrent TP53 mutation. Reverse-phase protein arrays revealed the synergistic molecular actions by INCB057643, DS3032b and venetoclax to induce cell-cycle arrest and apoptosis and to inhibit AKT/MEK/ERK/mTOR pathways, as well as potential drug resistance mechanisms mediated by upregulation of Mcl-1 and RAS/RAF/MEK/ERK pathways. In summary, these findings support subclassification of DLBCL/HGBCL with dual MYC/TP53 alterations, which demonstrates distinct pathobiologic features and dismal survival with standard therapy, therefore requiring additional targeted therapies. Implications: The clinical and pharmacologic studies suggest recognizing DLBCL with concomitant TP53 mutation and MYC abnormalities as a distinctive entity necessary for precision oncology practice. Visual Overview: http://mcr.aacrjournals.org/content/molcanres/19/2/249/F1.large.jpg.

Follicular lymphoma (FL) is an indolent B-cell neoplasm of germinal center origin. Standard treatment regimens consist of anti-CD20 therapy with or without chemotherapy. While high response rates to initial therapy are common, patients ultimately relapse or have progressive disease. Clinical risk factors such as the Follicular Lymphoma International Prognostic Index (FLIPI) have been identified, but there is a need for prognostic and predictive biomarkers. We studied markers of lymphoma cells and tumor microenvironment by immunohistochemistry in tissue samples from patients enrolled in 1 of 4 phase 2 trials of anti–CD20-based biological therapy for previously untreated grades 1 to 2 or 3A FL. Results were correlated with progression-free survival (PFS) and PFS status at 24 months. The 4 trials included 238 patients (51.1% male, median age: 55 y) with stage III, IV, or bulky stage II disease. By FLIPI, 24.6% had low-risk, 56.8% had intermediate-risk, and 18.6% had high-risk disease. The outcome differed significantly for patients treated with lenalidomide and rituximab (CALGB 50803) compared with the other 3 trials (median: PFS not reached vs. 3.0 y, hazard ratio=3.47, 95% confidence interval: 2.11-5.72); therefore, data were stratified by clinical trial (CALGB 50803 vs. all others) and adjusted for FLIPI risk group. Among 154 patients with available tissue, interfollicular BCL6 positivity, interfollicular CD10 positivity, and elevated Ki67 proliferation index ≥30% within neoplastic follicles were each associated with inferior PFS and a high risk of the early event by PFS status at 24 months. We identify promising biomarkers for FL risk stratification that warrant further validation in phase 3 trials.

Abstract Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity of B-cell lymphoma. Cell-of-origin (COO) classification of DLBCL is required in routine practice by the World Health Organization classification for biological and therapeutic insights. Genetic subtypes uncovered recently are based on distinct genetic alterations in DLBCL, which are different from the COO subtypes defined by gene expression signatures of normal B cells retained in DLBCL. We hypothesize that classifiers incorporating both genome-wide gene-expression and pathogenetic variables can improve the therapeutic significance of DLBCL classification. To develop such refined classifiers, we performed targeted RNA sequencing (RNA-Seq) with a commercially available next-generation sequencing (NGS) platform in a large cohort of 418 DLBCLs. Genetic and transcriptional data obtained by RNA-Seq in a single run were explored by state-of-the-art artificial intelligence (AI) to develop a NGS-COO classifier for COO assignment and NGS survival models for clinical outcome prediction. The NGS-COO model built through applying AI in the training set was robust, showing high concordance with COO classification by either Affymetrix GeneChip microarray or the NanoString Lymph2Cx assay in 2 validation sets. Although the NGS-COO model was not trained for clinical outcome, the activated B-cell–like compared with the germinal-center B-cell–like subtype had significantly poorer survival. The NGS survival models stratified 30% high-risk patients in the validation set with poor survival as in the training set. These results demonstrate that targeted RNA-Seq coupled with AI deep learning techniques provides reproducible, efficient, and affordable assays for clinical application. The clinical grade assays and NGS models integrating both genetic and transcriptional factors developed in this study may eventually support precision medicine in DLBCL.

8042 Background: Optimal consolidative therapy for primary central nervous system lymphoma (PCNSL) is not defined. Avoidance of whole brain radiation may reduce risk of neurotoxicity. Non-radiation consolidative options include myeloablative chemotherapy followed by autologous stem cell transplantation (HDT/ASCT) or non-myeloablative chemotherapy. Methods: This is a randomized phase 2, National Clinical Trials Network study of induction methotrexate (MTX) (8 g/m2days 1, 15), temozolomide (TMZ) (150-200 mg/m2 D7-11), and rituximab (RTX) (C1 D3, 10, 17, 24 and C2 D3, 10) in four 28-day cycles followed by one cycle of cytarabine (ARA-C) (2 g/m2 BID, D1, 2) (MTRA). Following induction, patients (pts) received consolidation with thiotepa (5 mg/kg BID, D -5, -4) plus carmustine (400 mg/m2, day -6) and ASCT (Arm A) or one cycle of ARA-C (2 g/m2 BID, D1-4) plus infusional etoposide (40 mg/kg over 96h) (Arm B). The primary endpoint was median progression-free survival (PFS), designed to compare consolidation regimens. This report describes the results of the 5 cycles of induction therapy. Results: 113 pts (median age 61 years, range 33-75) were randomized (Arm A: 57, Arm B: 56) across 27 centers. 108 eligible pts who received induction therapy were evaluated. 36 pts (33.3%) did not proceed to consolidation, mainly due to disease progression (17), pt withdrawal (8), or adverse events including death (6). Grade 3 or 4 febrile neutropenia occurred in 12 pts (11.1%) during induction. Dose modifications of MTX were required in 75% of pts and 63.3% of cycles, mainly due to renal adjustments. Dose delays of MTX were required in 52.8% of pts and 22.2% of cycles. Overall response rate (CR, CRu, PR) at the end of induction was 65.7% (95% CI, 56%, 74.6%). Conclusions: While MTRA is feasible and active a significant proportion of pts did not receive consolidation, supporting the need to develop more effective induction strategies. Clinical trial information: NCT01511562 .

AbstractEnumeration of blasts and promonocytes is essential for World Health Organization (WHO) classification of myelomonocytic neoplasms. The accuracy of distinguishing blasts, promonocytes and monocytes, including normal vs abnormal monocytes, remains controversial. The objective of this analysis is to assess concordances between experienced hematopathologists in classifying cells as blasts, promonocytes, and monocytes according to WHO criteria. Each of 11 hematopathologists assessed glass slides from 20 patients [12 with chronic myelomonocytic leukemia (CMML) and 8 with acute myeloid leukemia (AML)] including blood and BM aspirate smears, and limited nonspecific esterase (NSE) stains. All cases were blindly reviewed. Fleiss’ extension of Cohen's kappa for multiple raters was used on these variables, separately for peripheral blood (PB) and bone marrow (BM). Spearman's rank correlation was used to assess correlations between each pair of hematopathologists for each measurement. For the classification based on the sum of blasts and promonocytes in the BM, Fleiss’ kappa was estimated as 0.744. For PB, categorizing patients according to the sum of blasts and promonocytes, Fleiss’ kappa was estimated as 0.949. Distinction of abnormal monocytes from normal monocytes in PB did not achieve a good concordance and showed strong evidence of differences between hematopathologists (P < .0001). The hematopathologists achieved a good concordance rate of 74% in CMML vs AML classification and a high k rate, confirming that criteria for defining the blasts equivalents (blasts plus promonocytes) could be applied consistently. Identification of monocyte subtypes (abnormal vs normal) was not concordant. Our results support the practice of combining blasts/promonocytes into a single category.

Abstract As part of a randomized, prospective clinical trial in large cell lymphoma, we conducted serial fluorodeoxyglucose positron emission tomography (FDG-PET) at baseline, after 2 cycles of chemotherapy (interim PET [i-PET]), and at end of treatment (EoT) to identify biomarkers of response that are predictive of remission and survival. Scans were interpreted in a core laboratory by 2 imaging experts, using the visual Deauville 5-point scale (5-PS), and by calculating percent change in FDG uptake (change in standardized uptake value [ΔSUV]). Visual scores of 1 through 3 and ΔSUV ≥66% were prospectively defined as negative. Of 524 patients enrolled in the parent trial, 169 agreed to enroll in the PET substudy and 158 were eligible for final analysis. In this selected population, all had FDG-avid disease at baseline; by 5-PS, 55 (35%) remained positive on i-PET and 28 (18%) on EoT PET. Median ΔSUV on i-PET was 86.2%. With a median follow-up of 5 years, ΔSUV, as continuous variable, was associated with progression-free survival (PFS) (hazard ratio [HR] = 0.99; 95% confidence interval [CI], 0.97-1.00; P = .02) and overall survival (OS) (HR, 0.98; 95% CI, 0.97-0.99; P = .03). ΔSUV ≥66% was predictive of OS (HR, 0.31; 95% CI, 0.11-0.85; P = .02) but not PFS (HR, 0.47; 95% CI, 0.19-1.13; P = .09). Visual 5-PS on i-PET did not predict outcome. ΔSUV, but not visual analysis, on i-PET predicted OS in DLBCL, although the low number of events limited the statistical analysis. These data may help guide future clinical trials using PET response-adapted therapy. This trial was registered at www.clinicaltrials.gov as #NCT00118209.