Risk Of Central Nervous System Relapse Research Articles

CNS relapse in high-grade B-cell lymphoma with MYC and BCL2 rearrangements and dark-zone signature–expressing DLBCL

AbstractHigh-grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBCL-DH-BCL2), or “double-hit lymphoma,” has been associated with a high risk of central nervous system (CNS) relapse. However, historic estimates are impacted by selection bias. We report CNS relapse rates associated with HGBCL-DH-BCL2 from a population-based cohort with complete fluorescence in situ hybridization testing, as well as diffuse large B-cell lymphoma morphology (DLBCL) tumors expressing the dark-zone gene expression signature (DZsig), which was originally derived from HGBCL-DH-BCL2. The 2-year CNS relapse risk in HGBCL-DH-BCL2 was 6.8%. CNS relapses were early, predominantly leptomeningeal (73%), and co-occurred with systemic relapse (64%). High-risk CNS International Prognostic Index (CNS-IPI) and concordant bone marrow involvement were associated with an elevated CNS relapse risk in HGBCL-DH-BCL2. The “refined cell-of-origin” classification assigned 20% of DLBCL morphology tumors with germinal center B-cell–like phenotype (GCB-DLBCL) into a distinct subgroup based on DZsig expression (DZsig+). CNS relapse risk in DZsig+ (2 year: 6.4%) was independent of HGBCL-DH-BCL2 status and was further stratified by the CNS-IPI. CNS relapse in DZsig-negative GCB-DLBCL was rare (2-year risk, 1.4%; P = .04 vs DZsig+) and exclusively parenchymal. Altogether, the CNS relapse risk in HGBCL-DH-BCL2 is lower than previously reported, and DZsig refines risk stratification in GCB-DLBCL.

Outcome of patients with diffuse large B-cell lymphoma and testicular involvement - real world data.

Patients with testicular lymphoma are at an increased risk of central nervous system (CNS) disease. Optimal strategy for CNS relapse prevention is unknown. We analyzed treatment strategies, cumulative incidence of CNS relapse and prognosis in 229 patients with diffuse large B-cell lymphoma (DLBCL) and testicular involvement: 157 primary testicular lymphomas (PTL) in clinical stages IE/IIE and 72 patients in advanced stages (T-DLBCL) IIIE/IV. Treatments for PTL vs. T-DLBCL included: rituximab-based chemotherapy (80.9% vs. 90.3%), orchiectomy (94.3% vs. 65.3%) and contralateral testicular irradiation (59.8% vs. 44.4%). Majority (84.3%) received CNS prophylaxis with similar rates of prophylactic methotrexate (intravenous 19.1% vs. 16.6%, intrathecal 40.8% vs. 40.4%, or both 24.2% vs. 27.8%) between PTL and T-DLBCL (p = 0.89). Median follow-up was 51.8 months. CNS relapses occurred in 14 (6.1%) of 63 relapsing patients. The 5-year cumulative incidence of CNS relapse in PTL was 4.5% and in T-DLBCL 12.1%. Median time to CNS relapse was 21.9 months. In univariate analyses, orchiectomy was the single significant factor associated with lower risk of CNS relapse in PTL (HR = 0.11 [95% CI, 0-0.124], p = 0.001). Rituximab significantly reduced CNS relapse risk in T-DLBCL (HR = 0.1002, p = 0.0005). Median progression-free survival (PFS) and overall survival (OS) following CNS relapse was dismal in T-DLBCL compared to PTL (PFS 1.6 vs. 37.8 months, p = 0.04 and OS 2.3 vs. 37.8 months, p = 0.05). This study confirmed a favorable impact of rituximab in prevention of CNS relapse in T-DLBCL. Methotrexate prophylaxis did not alter CNS relapse risk. Prognosis of CNS relapse is particularly poor in T-DLBCL.

CNS prophylaxis in large B-cell lymphomas: A balance with three pans.

Given the significant limitations of available literature, central nervous system (CNS) prophylaxis in large B-cell lymphomas remains debatable. Wilson and colleagues provide cautious recommendations, on a case-by-case basis, useful to guide discussion with individual patient. In daily practice, CNS relapse risk, prophylaxis safety and prognosis of CNS recurrence must be considered. Commentary on: Wilson etal. Central nervous system prophylaxis in large B-cell lymphoma: A British Society for Haematology Good Practice Paper. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19686.

Incidence of Central Nervous System Relapse in Primary Mediastinal Large B-Cell Lymphoma: Implications for Central Nervous System Prophylaxis

BackgroundPrimary mediastinal large B-cell lymphoma (PMBCL) is an uncommon type of aggressive B-cell non-Hodgkin lymphoma. PMBCL shares some clinical and biologic features with nodular sclerosis classic Hodgkin lymphoma (cHL). Central nervous system (CNS) relapse is exceedingly rare in cHL. Therefore, it may be expected that CNS relapse in PMBCL is also uncommon. Herein, we examined the incidence of CNS relapse in patients with PMBCL treated with standard chemoimmunotherapy. Patients and MethodsThis retrospective single center analysis included 154 patients with newly diagnosed PMBCL seen at Mayo Clinic. The CNS relapse rate was calculated using a competing risk model, with death considered as a competing risk. ResultsWith a median follow-up of 39 months, 3 patients experienced CNS relapse, all associated with systemic relapse. The cumulative incidence of CNS relapse for the entire cohort was 1.43% (95% CI, 0.3%-4.6%) at 1 year and 2.21% (95% CI, 0.6%-5.8%) at both 2 and 5 years. For those who did not receive CNS prophylaxis (n = 131), the incidence was 0.85% (95% CI, 0.1%-4.2%) at 1 year and 1.80% (95% CI, 0.3%-5.8%) at both 2 and 5 years. All 3 patients who experienced CNS relapse had R-CHOP as frontline therapy; 2 patients did not receive any CNS prophylaxis, while 1 patient received intrathecal CNS prophylaxis. ConclusionThe risk of CNS relapse in PMBCL appears to be very low after treatment with standard chemoimmunotherapy, suggesting routine CNS prophylaxis is not necessary.

Patient's HLA Genotype Is Associated With the Risk of Central Nervous System Dissemination and Clinical Disease Presentation in Diffuse Large B-cell Lymphoma.

Central nervous system (CNS) involvement in aggressive B-cell lymphoma, either as a primary or secondary event to systemic disease, portends a poor prognosis. This study sought to identify patients at high risk for CNS relapse by analyzing their human leukocyte antigen (HLA) genotypes. We retrospectively examined the HLA genotypes of 164 patients with systemic lymphoma, primary CNS lymphoma, and CNS relapse of systemic lymphoma. Patient records were analyzed, and HLA typing was performed by the Finnish Red Cross Blood Service. After excluding patients who received CNS prophylaxis, 131 patients were included in the final analysis. A strong association was found between the HLA-A*31 genotype and CNS disease (p=0.001). Additionally, various HLA genotypes were linked to lactate dehydrogenase levels, extranodal disease, International Prognostic Index score, and disease stage. The patient's genetic constitution, rather than solely disease-related factors, plays a role in the tropism of lymphoma for the CNS. If confirmed in a larger study, defining the HLA genotype of a lymphoma patient could provide valuable information for predicting CNS relapse.

The CNS relapse in T-cell lymphoma index predicts CNS relapse in patients with T- and NK-cell lymphomas

AbstractLittle is known about risk factors for central nervous system (CNS) relapse in mature T-cell and natural killer cell neoplasms (MTNKNs). We aimed to describe the clinical epidemiology of CNS relapse in patients with MTNKN and developed the CNS relapse In T-cell lymphoma Index (CITI) to predict patients at the highest risk of CNS relapse. We reviewed data from 135 patients with MTNKN and CNS relapse from 19 North American institutions. After exclusion of leukemic and most cutaneous forms of MTNKNs, patients were pooled with non-CNS relapse control patients from a single institution to create a CNS relapse–enriched training set. Using a complete case analysis (n = 182), including 91 with CNS relapse, we applied a least absolute shrinkage and selection operator Cox regression model to select weighted clinicopathologic variables for the CITI score, which we validated in an external cohort from the Swedish Lymphoma Registry (n = 566). CNS relapse was most frequently observed in patients with peripheral T-cell lymphoma, not otherwise specified (25%). Median time to CNS relapse and median overall survival after CNS relapse were 8.0 and 4.7 months, respectively. We calculated unique CITI risk scores for individual training set patients and stratified them into risk terciles. Validation set patients with low-risk (n = 158) and high-risk (n = 188) CITI scores had a 10-year cumulative risk of CNS relapse of 2.2% and 13.4%, respectively (hazard ratio, 5.24; 95% confidence interval, 1.50-18.26; P = .018). We developed an open-access web-based CITI calculator (https://redcap.link/citicalc) to provide an easy tool for clinical practice. The CITI score is a validated model to predict patients with MTNKN at the highest risk of developing CNS relapse.

CAR T-cell therapy in mantle cell lymphoma with secondary CNS involvement: a multicenter experience

Secondary central nervous system (CNS) involvement in Mantle cell lymphoma has poor outcomes, with limited data for efficacy of CAR-T therapy. This study reports encouraging response with reasonable safety profile, but risk of CNS relapse remains high in such patients.

Impact of Central Nervous System (CNS) Leukemia Status-Based Therapeutic Protocol Change on the Incidence of CNS2 Diagnosis in Pediatric B-Lymphoblastic Acute Leukemia

B-lymphoblastic acute leukemia (B-ALL) is the most prevalent cancer among children, and prophylactic central nervous system (CNS) therapy has significantly contributed to high cure rates for the past 50 years. However, relapses in bone marrow and/or CNS continue to pose challenges to achieving cure for all patients, especially in those with high-risk disease. CNS status at diagnosis, defined as CNS1 (no blasts present), CNS2 (blasts with <5 total white blood cells [WBC] per mm 3 in a cerebrospinal fluid [CSF] sample), and CNS3 (blasts with ≥5 total WBC per mm 3 or grossly traumatic), plays a crucial role in determining treatment stratification. In the past, patients with CNS1 and CNS2 received similar therapy, but evidence suggested that those with CNS2 were at a higher risk for marrow and/or CNS relapse. As a result, the Children's Oncology Group (COG) frontline trials AALL1131 and AALL0932 implemented additional CNS therapy for CNS2 patients beginning in 2012 and 2016, respectively, specifically twice weekly intrathecal chemotherapy until CSF cleared of disease 3 consecutive times. This change highlighted the necessity for accurate identification of CNS2. Based on anecdotal observation, we hypothesized that the incidence of CNS2 among pediatric B-ALL patients at diagnosis was higher after this therapeutic change due to pathologist awareness of its implications for patient management. The electronic medical records of all consecutive pediatric patients diagnosed with B-ALL at Children's Hospital Los Angeles (CHLA) from September 2008 to December 2019 were reviewed. CSF WBC count and blast involvement were used to calculate CNS status. Blast involvement was determined by one or more pathologists per case by morphologic review of cytocentrifuged CSF material. The patients were divided into two cohorts, one before (cohort A) and one after (cohort B) the COG AALL0932 protocol change (May 20, 2016). Differences between cohorts were evaluated via Fisher's exact test and Wilcoxon rank sum test. All tests were two-sided, except for CNS2 status, and significance level was set a priori at 0.05. During the study period, 391 patients were diagnosed with B-ALL at CHLA. These included 192 patients prior to the CNS status-based therapeutic change (cohort A) and 199 patients after the therapeutic change (cohort B). The incidence of CNS2 status was higher in cohort B (20%) than in cohort A (13%) (p=0.052). Conversely, the incidence of CNS1 status was lower in cohort B (77%) than in cohort A (85%), while the incidence of CNS3 was similar before (5%) and after (4%) the protocol change. There were no differences between the cohorts in patient age at diagnosis [cohort A: mean age 8.91 years (SD 5.67 years) vs. cohort B: mean age 8.10 (SD 5.62 years); p=0.20], sex (cohort A: 59.9% male vs. cohort B: 58.8% male; p=0.80), or ethnicity (cohort A: 76.0% Hispanic vs. cohort B: 67.7% Hispanic; p=0.09). These data suggest that the incidence of CNS2 status in pediatric patients with B-ALL at our institution was higher after (20%) than before (13%) the COG protocol changes that began treating CNS2 patients more intensively than CNS1 patients. In addition to increased frequency of intrathecal chemotherapy, in the ongoing frontline COG standard-risk ALL trial, patients with CNS2 status and neutral cytogenetics are upstaged to higher-risk therapy irrespective of end-induction response. A limitation of this study is that pathologist reviewers of CSF cytospin morphology at the time of CNS assignment differed during the two time periods, such that an observational bias cannot be entirely excluded. Notably, flow cytometry - a more sensitive methodology than cytospin morphology for detection of leukemic cells in CSF material - was not used in these cohorts, but increasingly widespread adoption of such techniques may further increase the incidence of CNS2, including in patients who would otherwise have been diagnosed with CNS1 disease (by cytospin morphology) and as such may be overtreated. Future directions of our study include examination of clinical outcome as well as recent (2021-present) patterns of flow cytometry use in CSF specimens and associated diagnoses of CNS disease in pediatric patients with B-ALL at diagnosis.

Deciphering Transcriptomic and (Epi)Genetic Signatures of Central Nervous System Infiltration in Patients Diagnosed with Diffuse Large B-Cell Lymphoma

Introduction Central Nervous System (CNS) involvement in Diffuse Large B Cell Lymphoma (DLBCL) is a rare complication with bad prognosis. The CNS Prognostic Index is employed to categorize patients at a high risk of CNS relapse; however, its effectiveness is not accurate. The discovery of precise biomarkers for predicting CNS involvement in DLBCL patients remains unmet. Our objective was to characterize the immune, transcriptomic, genomic and epigenomic hallmarks of systemic tumors at diagnosis of patients who later experienced relapse in the CNS. By exploring these biological profiles, we sought to gain valuable insights into the underlying mechanisms and potential biomarkers associated with CNS relapse in DLBCL. Methods We conducted a retrospective study including 38 patients diagnosed with nodal DLBCL who experienced relapse within the first two years after diagnosis. Among these patients, 12 individuals relapsed specifically in the CNS, while 26 relapsed in systemic sites. As a control group, we included 21 patients who did not relapse. DNA and RNA were extracted from FFPE tumor samples collected at diagnosis. To evaluate immune cell infiltration, we utilized the nCounter PanCancer Immune Profiling Panel (Nanostring); cell-of-origin (COO) was determined using the Lymph2Cx assay. Transcriptomic profiles were generated by bulk RNA sequencing and mutational analysis was performed using a custom targeted NGS panel, which included the most frequently mutated genes observed in lymphoid neoplasms. Methylation profiles were obtained using the Illumina Infinium MethylationEPIC Array 850K. Results Immune profiling analysis showed cell composition was not significantly different between groups; however, we observed distinct immune gene expression patterns at diagnosis in patients who experienced CNS relapse. Multiple genes were overexpressed in the CNS-relapsed group compared to non-relapsed group, which encompassed various functional categories including chemokine signaling such as IL7R (FC=2; P=0.05) and CCR6 (FC=3.4; P=0.01); adhesion like VCAM1 (FC=1.6; P=0.03) and ITGA4 (FC=2.2; P=0.006); and immune regulation such as CD1A (FC=4.8; P=0.001), LTB (FC=3.3; P=0.009) and BTLA (FC=2.3; P=0.02) (Fig.1A). The ITGA4 gene also presented higher expression levels in the CNS-relapsed group when compared to both systemic-relapsed and non-relapsed groups combined (FC=1.7; P=0.03). No significant differences were observed in the COO classification between groups. Whole-genome transcriptomic data revealed enrichment in gene sets associated with proliferation and survival in the CNS-relapsed group (Fig.1B). Analysis of genetic alterations indicated that patients with CNS relapse exhibited an increased mutation load and frequency in PIM1, IGLL5, and KMT2D genes. Finally, analysis of the CNS relapse-related epigenome showed 343 differentially hypomethylated CpG sites compared to both systemic and non-relapsed groups together, affecting a total of 211 genes. Pathway enrichment analysis of these genes revealed a link between CNS infiltration and cell migration and locomotion. Conclusions Tumors from DLBCL patients that will relapse in the CNS present a higher chemokine, adhesion and proliferation signatures at diagnosis. Of notice, BTLA, CCR6 and IL7R proteins have been previously reported to be implicated in B cell entry into the CNS in B-cell malignancies. Interestingly, patients with CNS relapse demonstrated significant overexpression of the ITGA4 gene, which encodes the integrin α4 subunit (CD49d) of the Very Late Antigen-4. Engagement between CD49d on B cells and its endothelial ligand VCAM-1 is required for migration of these cells across the blood-brain barrier. In fact, Natalizumab (anti-CD49d mAb) is administered in multiple sclerosis to impede entrance and accumulation of B cells in the brain. Initial experiments in mice have shown increased expression of CD49d in lymphoma B cells that have infiltrated the brain, compared to those in the spleen. Herein, we have demonstrated that DLBCL cells at diagnosis already own specific transcriptomic and (epi)genetic hallmarks that could confer a higher capacity to infiltrate the CNS. Validation of these findings in larger cohorts of patients could improve selection of patients with an increased risk of CNS involvement in need of prophylactic CNS-directed therapies at diagnosis.

CNS Prophylaxis Among Patients with HIV-Associated Diffuse Large B-Cell Lymphoma - a Single Center Retrospective Study

Title: CNS Prophylaxis Among Patients with HIV-Associated Diffuse Large B-Cell Lymphoma - A Single Center Retrospective Study Introduction: Patients with Human Immunodeficiency Virus (HIV) are known to develop Lymphoma at a higher rate compared with the general population, with Diffuse Large B-Cell Lymphoma (DLBCL) being the most common subtype. Historically, before the advent of HIV treatment with antiretroviral therapy (ART), HIV-associated DLBCL was considered a more aggressive type of lymphoma and all patients were treated with central nervous system (CNS) prophylaxis. However, since ART has been widely adopted, there is some data to suggest that HIV-associated DLBCL among those taking ART more closely resembles de-novo DLBCL and may not need to be universally treated with CNS prophylaxis. There are no good prospective trials evaluating which patients who develop HIV-associated DLBCL while on ART should receive CNS prophylaxis. Furthermore, studies that tried to predict which DLBCL patients are at greater risk for CNS relapse explicitly excluded patients with HIV. Despite the absence of data, guidelines have shifted and current NCCN guidelines now recommend that HIV patients with DLBCL should be risk stratified as de-novo DLBCL patients with respect to CNS directed therapy. In this study, patients with HIV-associated DLBCL were retrospectively analyzed to understand the patterns of CNS prophylaxis and effects on relapse free survival. Methods: The Electronic Medical Record was queried at a large academic medical center in New York City for patients with HIV-associated DLBCL between the years of 2012 and 2021 using ICD-10 codes. Other subtypes of Lymphoma such as Burkitt's or Plasmablastic Lymphoma were excluded. Patients who did not receive their entire treatment course within the institution were also excluded. Clinical characteristics at diagnosis, treatment type, CNS prophylaxis, and survival data was collected and analyzed. Results: A total of 38 patients were identified according to the inclusion criteria. 26 patients (68%) underwent screening lumbar punctures (LPs) for CNS disease while 12 patients (32%) did not. The two groups were not statistically different within any categories except for LDH, where the LP group had a median LDH of 492 units/L and the non-LP group had a median LDH of 241 units/L (p-value: 0.031). The two groups were not statistically different in cell of origin subtypes, stage, bone marrow involvement, kidney/adrenal involvement, the use of ART prior to diagnosis, IPI or CNS-IPI scores. In addition, among the group that had an LP done with no CNS involvement (n=25), there was no statistical difference in relapse-free survival among those who received adequate CNS prophylaxis and those who did not (p-value 0.886). Conclusions: Among patients with HIV-associated DLBCL in a large academic medical center in New York City, there is no reliable indicator to predict which were offered screening lumbar punctures and which were not. Clinicians may be using additional measures of aggressiveness not accounted for in standard IPI and CNS-IPI scoring algorithms. Furthermore, there was no clear benefit in relapse free survival among high-risk patients who received adequate CNS prophylaxis versus those who did not in this limited sample size. Further research is needed to determine whether patients with HIV-associated DLBCL should be risk stratified similarly to de-novo DLBCL patients with respect to CNS prophylactic therapy.

The Outcome of Diffuse Large B-Cell Lymphoma Patients with Testicular Involvement - Real World Data

Introduction: Patients (pts) with testicular lymphoma (TL) have an increased risk of central nervous system (CNS) relapse. In rituximab era, the reported incidence vary from 10% (in limited disease) to 25% (advanced disease). More data is needed to guide the managment of TL pts in current era. Optimal strategy for CNS relapse prevention is uncertain. Methods: We studied consecutive pts diagnosed between 2000 and 2022 with testicular diffuse large B-cell lymphoma (DLBCL) prospectively observed in the Czech Lymphoma Study Group Project NiHiL (Clinical Trial gov. NCT03199066). Objectives were to analyze the cumulative incidence of CNS relapse, time to CNS relapse, PFS and OS. The impact of various treatment strategies on CNS relapse was analyzed. Results: We identified 229 pts with testicular involvement: 157 pts with primary testicular lymphoma (PTL) in clinical stage I or II and 72 pts in advanced stage (AD) III or IV. Median age was 70 years (range 33 - 87). Rituximab-based chemotherapy received 192 (83.8%) pts including 127 (81%) cases with PTL. Following localized treatments were used more often in PTL compared to AD: unilateral orchiectomy [148 (94.3%) vs. 47 (65.3%); p < 0.0001], testicular irradiation (RT) [116 (61.7%) vs. 40 (38.7%); p = 0.005]. Most patients (85%) received some form of CNS prophylaxis. There were similar rates in use of prophylactic methotrexate (MTX) between PTL and AD (p = 0.88): intrathecal (i.t.) MTX 64 (40.8%) vs. 29 (40.3%), intravenous (i.v.) MTX with or without cytarabine 20 (12.8%) vs. 7 (9.7%); combined i.t. and i.v. MTX 38 (24.2%) vs. 20 (27.8%). Out of 229 cases 25 (15.9%) PTL and 11 (15.3%) AD pts did not receive any CNS prophylaxis. Median follow-up was 51.8 months.Overall 63 (27.5%) pts relapsed including 14 (6.1%) relapses in CNS. Median time to CNS relapse was 21.9 months and to other systemic relapse was 14.7 months (p = 0.63). The 5-year cumulative incidence of CNS relapse in PTL was 4.55% (95% confidence interval [CI], 0.1 - 28.6) and in AD 12.07% (95% CI 0.8 - 39.6), respectively. In univariate analyses, MTX prophylaxis (i.v. and/or i.t.) and testicular RT had no impact on CNS relapse (p = 0.49 and p = 0.60, respectively). Orchiectomy was the single significant factor associated with lower risk of CNS relapse in PTL (hazard ratio [HR] = 0.11[95% CI 0 - 0.124]; p = 0.001). Rituximab significantly reduced CNS relapse in AD with testicular involvement (HR = 0.1002 [95% CI 0.0 - 0.45]; p = 0.0005). Out of 14 pts with CNS relapse 8 died due to lymphoma progression. Median progression-free survival (PFS) and overall survival (OS) in PTL was significantly better when compared to AD (PFS 92.9 vs. 28.1 months, p < 0.0006; OS 108.7 vs. 56.7 months, p = 0.0002). Median PFS2 and OS2 since CNS relapse was dismal in AD compared to PTL (PFS2 1.6 vs. 37.8 months, p = 0.04 and OS2 2.3 vs. 37.8 months, p = 0.05). Conclusions: The rate of CNS relapses in PTL and advanced disease with testicular involvement is lower than previously reported. This study confirmed a significant favorable impact of rituximab in prevention of CNS relapse. Notably, methotrexate prophylaxis i.v. or i.t. did not alter the CNS relapse risk. Prognosis of CNS relapse is particularly poor in advanced disease. This work was supported by grant AZV NU21-03-00411 from the Ministry of Health of the Czech Republic and by the Cooperatio Program, research area “Oncology and Haematology”

Incidence and Risk Factors for Central Nervous System Relapse after Allogeneic Hematopoietic Stem Cell Transplantation in Adult Patients with Acute Lymphoblastic Leukemia

Background Acute lymphoblastic leukemia (ALL) is frequently accompanied with the involvement of the central nervous system (CNS). The clinical prognosis for ALL patients with CNS disease is generally unfavorable, and prophylactic measures such as intrathecal chemotherapy are highly recommended. In adult ALL patients, hematopoietic stem cell transplantation (HSCT) presents a potential curative approach. However, there are currently only a few reports available on the risk factors and epidemiology of CNS relapse after HSCT. Method We conducted a retrospective single-center cohort study involving 1043 patients diagnosed with either acute lymphoblastic leukemia (ALL) or mixed phenotype acute leukemia (MPAL). These patients were treated at our center using the same treatment protocol between 2009 and 2022. During the remission induction phase, we utilized a modified hyper-CVAD regimen, along with six rounds of prophylactic intrathecal (IT) chemotherapy. High-risk patients who had suitable donors underwent allogeneic hematopoietic stem cell transplantation (HSCT) as part of their post-remission therapy. Diagnosis of central nervous system (CNS) leukemia was established when neurologic symptoms were observed in correlation with CNS lesions on imaging studies, or when leukemic blasts were detected in the cerebrospinal fluid (CSF). In our study, we examined the incidence, risk factors, and survival outcomes of patients who experienced CNS relapse after transplantation. Results Among the entire cohort of 1043 patients, CNS involvement was observed in 3 (0.3%) patients at initial diagnosis and 12 (1.2%) during chemotherapy. We proceeded with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 755 consecutive patients. Among these 755 patients, 3 had CNS leukemia prior to transplantation. Among the group of 755 patients, a total of 224 (29.6%) experienced relapse. Of these relapses, 142 (18.8%) were bone marrow relapses alone, 54 (7.1%) were extramedullary relapses alone (with CNS involvement in 21 [38.8%]), and 28 (3.7%) had both bone marrow and extramedullary relapses (with CNS involvement in 13 [46.4%]). Overall, extramedullary relapse was observed in 82 (10.8%) patients, with CNS involvement in 34 (4.5%) cases, following allo-HSCT. The 5-year cumulative incidence of CNS relapse was 4.6%, which was significantly higher in patients with Philadelphia chromosome-positive (Ph-positive) ALL (9.4% vs. 1.0%, p <0.001), as well as those with a high leukocyte count at diagnosis (8.3% vs. 2.6%, p = 0.001). Among the Ph-positive ALL cases, a high leukocyte count (n=151) was associated with a higher prevalence of pre-HSCT minimal residual disease (MRD) > 0.1% (n=88), which exhibited a significantly increased incidence of CNS relapse (16.6% vs. 6.8%, p = 0.009). Factors such as age, number of intrathecal chemotherapy treatments, conditioning intensity, and dose of anti-thymocyte globulin did not have a significant impact. Among the 34 patients with CNS relapse, 21 (61.7%) had isolated CNS relapse, and 7 of them showed evidence of positive MRD. With the exception of one patient who refused further treatment, the remaining 33 patients received initial CNS local therapy, including intrathecal chemotherapy combined with radiotherapy in 27 (82.0%) cases, intrathecal chemotherapy alone in 6 cases, and radiotherapy alone in 4 cases. Out of these patients, 22 were treated with dasatinib or ponatinib, while 6 received salvage chemotherapy. The median overall survival for patients with CNS relapse was 11.2 months, which was 19.8 months for those with isolated CNS relapse and 10.9 months for those with CNS relapse accompanied by bone marrow relapse (p = 0.077). The subsequent 2-year cumulative incidence of CNS relapse was 30%. Conclusion Based on our findings, the current prophylaxis strategy employed for the prevention of post-HSCT CNS relapse in adult ALL appears to be effective. However, our data indicates that MRD-positive Ph-positive ALL requires distinct management due to its significantly elevated risk of CNS relapse. New strategies including prophylactic radiotherapy for this high-risk subgroup must be considered to prevent post-HSCT CNS disease.

RCHOP Plus High-Dose Methotrexate As First-Line Therapy in Large B-Cell Lymphoma with Testis Involvement

Primary testicular lymphoma (PTL) and diffuse large B-cell lymphoma with secondary testicular involvement (DLBCL-T) are rare subtypes of lymphomas associated with poor prognosis and a high risk of central nervous system (CNS) relapse. The optimal CNS prophylaxis strategy for these subtypes remains uncertain. High-dose methotrexate (HD-MTX) is debated for CNS prophylaxis, but its efficacy in this setting is unknown. This study aimed to retrospectively analyze the use of HD-MTX in combination with chemotherapy (R HD-MTX CHOP) as frontline treatment for PTL and DLBCL-T and to compare the biological characteristics of these two forms of testicular involvement. Data from patients who received R HD-MTX CHOP as first-line treatment for DLBCL-T or PTL between 2010 and 2020 were collected retrospectively. The study included 15 patients, 5 with PTL and 10 with DLBCL-T. The overall response rate was 86%, with 73% of patients achieving complete remission. Treatment-related adverse events were generally manageable, with febrile neutropenia being the most common. Two patients experienced CNS relapse, both from the DLBCL-T subgroup, with a median time of 10.7 months from diagnosis to CNS relapse. None of the PTL patients receiving HD-MTX experienced relapse during the median follow-up of 6.08 years (Figure 1A), compared to 8/10 DLBCL-T (p=0.007). All five PTL cases had a non-germinal center phenotype, while 7 out of 10 DLBCL-T cases were non-germinal center. One DLBCL-T case exhibited high-grade lymphoma. Myc expression was positive in 3 out of 10 patients assessed, of whom all were double expressors. Bcl-2 expression was positive in all 13 assessable patients, while Bcl-6 expression was positive in 6 patients. Myc, Bcl-2, and Bcl-6 rearrangements were assessed in 10 patients and were present in 1 patient who was found to have triple-hit lymphoma. No other patient had double-hit lymphoma or any significant rearrangement. Polysomy of Myc, Bcl-2, and/or Bcl-6 was found in 2 patients. PDL1 expression was observed in one out of six patients analyzed, while no PD1 expression was detected. In 8 out of 15 patients with available tissue material, next-generation sequencing using a panel targeting 43 lymphoid genes was performed. Among these 8 patients, 87% exhibited gain-of-function mutations in MYD88 (MYD88 L265P), and 62% had missense mutations in CD79B at position Y196. Multiple mutations in the PIM1 gene, a known target of aberrant somatic hypermutation, were also observed in 7 patients. Non-recurrent mutations were detected in various genes, including PRDM1, CD58, B2M, CREBBP, CIITA, CARD11, CDKN2A, EP300, CCDND3, FOXO1, IRF4, NFKBIE, and TCF3 (Figure 1B). Ig rearrangement was analyzed in 4/9 patients with available DNA. All 4 were clonal, with distinct but mutated VH segments (sequence identity between 81 and 89%). This study suggests that HD-MTX in combination with RCHOP chemotherapy is highly effective in preventing CNS relapse in PTL but less so in DLBCL-T. DLBCL-T had a higher risk of CNS relapse and poorer outcomes compared to PTL. Further studies are needed to determine the optimal timing and sequence of HD-MTX in DLBCL-T, as well as alternative treatment approaches. PTL and DLBCL-T have distinct clinical presentations and responses to frontline chemotherapy with HD-MTX prophylaxis. PTL may benefit from HD-MTX in preventing relapse, while alternative treatments should be explored for DLBCL-T. Future studies should consider PTL and DLBCL-T as separate entities to better understand their characteristics and optimize treatment strategies.

CNS Prophylaxis in Adult ALL Patients after Stem Cell Transplantation: An EBMT Survey on General Practice

Introduction Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment for acute lymphoblastic leukemia (ALL) resulting in long-term remission. Despite advances in therapy, disease progression remains the major cause of mortality following HSCT accounting for 20-50% of all deaths. The central nervous system (CNS) is the most common extra-medullary site of disease progression after transplant in ALL. The established practice of CNS prophylaxis for ALL has largely been modeled in the pediatric population, given the higher incidence of ALL in this age group compared with adults. Although the use of CNS prophylaxis as part of the upfront treatment for ALL has led to significant decreases in CNS relapse and improved outcomes overall, the routine use of post-HSCT prophylactic CNS therapy as a strategy to prevent CNS relapse after transplant in adult patients is still controversial. Studies that utilized post-HSCT CNS prophylaxis have reported disparate results and there is no generalized consensus regarding the use of post-transplant CNS prophylaxis to prevent relapse. Methods In order to assess the current practice of post-HSCT prophylactic CNS therapy in preventing CNS relapse in ALL patients, we carried out a survey among EBMT centres to describe intrathecal (i.t.) prophylaxis or irradiation in HSCT for ALL in both patients with or without CNS manifestations at any time of disease (first or second complete remission [CR1, CR2] and relapsed/refractory [R/R] ALL). EBMT centres were asked whether they usually give i.t. prophylaxis or cranial irradiation before and after HSCT, and which drugs they use. Results Of 410 invited centres, 55 (13%) replied to the survey. Tables 1 shows the number of centres which use i.t. prophylaxis or cranial irradiation. Most of the 55 centres used both pre-and post i.t. prophylaxis and triple prophylaxis (steroids, cytarabine [AraC] and methotrexate [MTX]) was the most frequently adopted. As expected in the pre-transplant phase, almost 70% of centres use i.t. chemotherapy irrespective of the phase of the disease or of the use of total body irradiation (TBI) as conditioning regimen. In the post-transplant phase, the rate of i.t prophylaxis varies according to disease phase, TBI use, and history of CNS involvement pre HSCT. In patients w/o history of CNS involvement in CR1, i.t. prophylaxis is given in 23.6% and 21.5% (with or w/o TBI use, respectively). Notably in CR2 pts, i.t. prophylaxis is given in 20% of cases if the conditioning regimen includes TBI, and in 74.5% of cases if TBI is not used; 32.7% and 46.9% R/R pts (with or without TBI use, respectively) are given i.t. prophylaxis. In the setting of patients with history of CNS involvement in CR1, i.t. prophylaxis is given in and 30.9% and 38.2% (with or without TBI use, respectively); in CR2 pts, i.t. prophylaxis is given in 38.9% of cases if the conditioning regimen does not include TBI, and in 29.1% of cases if TBI is used; 38.9% and 45.3% R/R pts (with or without TBI use, respectively) are given i.t. prophylaxis. Pre-transplant cranial irradiation is planned in less than 10% of centres in CR1 and CR2 patients without CNS involvement, irrespective of the use of TBI in the conditioning regimen, while it is used in 22.4% and 25% of patients with R/R disease with or without TBI use for transplant, respectively. In the setting of patients with CNS involvement, among those in CR1 and CR2, approximately 30% receive pre-transplant cranial irradiation irrespective of TBI use, while 32.7% and 34.6% of patients receive cranial irradiation (with or without TBI use, respectively). Its use after transplant is uncommon irrespective of disease status at treatment. Conclusions CR2 pts (without CNS involvement) seem to be at higher risk of CNS relapse if TBI is not included in the conditioning regimen. R/R pts are always considered at higher risk for CNS relapse if TBI is not included in the conditioning regimen. Cranial irradiation before treatment is used in almost 1 out of 3 pts with CNS involvement despite the use of TBI as the conditioning regimen, and 1 out 4 R/R pts without CNS involvement at transplant. The rate of cranial irradiation after transplant is extremely low, irrespective of diseases status, previous CNS involvement or TBI use. In conclusion, the use of i.t. prophylaxis after HSCT in patients with or without CNS involvement is variable among European transplant centres, also in the era of novel therapies for patients with ALL.

Diffuse Large B-Cell Lymphoma CNS Relapse Prophylaxis with Intrathecal or High-Dose Intravenous Methotrexate

Introduction: Central nervous system (CNS) relapse is a relatively infrequent but often fatal complication of the most common subtype of non-Hodgkin lymphoma, diffuse large B-cell lymphoma (DLBCL). Median overall survival (OS) after DLBCL relapse in the CNS is about 4 months. Despite identifying patients at high risk of developing CNS relapse using the CNS international prognostic index (CNS-IPI) score, it has been difficult to validate any specific strategy. Various chemotherapies and administration methods have been tested. Thus far, only the addition of rituximab to chemotherapy has yielded significant results. Our objective is to determine if administering prophylactic chemotherapy is efficacious in preventing DLBCL relapse in the CNS. Methodology: We collected retrospective data for patients with newly diagnosed DLBCL treated with rituximab and anthracycline-based chemotherapy from 2010 to 2020 in the Northwell Health system to determine the efficacy of CNS prophylaxis. Patients with CNS disease at diagnosis, primary testicular lymphoma, primary mediastinal large B-cell lymphoma, and HIV-associated lymphoma were excluded from this study. CNS prophylaxis was defined as receiving at least two doses of prophylactic chemotherapy, whether intravenous or intrathecal. Follow up for at least one year after diagnosis was required for inclusion. Overall survival (OS) was defined as the time difference between the date of definitive diagnosis to death or last date of contact. Other potential prognostic factors including double hit status and cell of origin, germinal center B-cell (GCB) vs. non-germinal center B-cell (non-GCB), were also evaluated. Pearson's chi-square analysis was used to compare the rate of DLBCL relapse in the CNS based on whether patients received CNS prophylaxis. Low risk was defined as CNS-IPI score 0 to 3 and high risk as CNS-IPI score 4 to 6. Kaplan-Meier analysis with log-rank (Mantel-Cox) testing was used to determine if any significant OS benefit was observed for the low and high-risk groups based on CNS-IPI score. Results: Of the 437 charts reviewed, 127 were eligible for inclusion. Most patients were male (56.7%). Median age was 69 years and median Eastern Cooperative Oncology Group (ECOG) performance status was 1. Most cases were non-GCB (44.9%, as 25% of cases were missing data) and not double hit (85%). Of the 35 patients at high risk for CNS relapse, 27 (77%) received prophylaxis. Intrathecal methotrexate (IT MTX) was given to 26 patients (96%) and high dose intravenous methotrexate (HD MTX) was given to 1 patient. CNS relapse occurred in 6 patients, of which 5 had a low-risk CNS-IPI score. One of the five patients in the low-risk group and the one patient in the high-risk group that had CNS relapse received prophylaxis. No significant difference in overall relapse rates were observed based on whether prophylaxis was given, X 2 (1, N = 127) = 0.30, p = .59. Kaplan-Meier analysis showed no difference in OS after stratification of patients by CNS-IPI score into the high-risk ( p = .50) and low-risk ( p = .24) groups. HD MTX was not administered frequently enough to determine its efficacy. Neither cell of origin (X 2 (1, N = 95) = 2.95, p = .086) nor double hit status (X 2 (1, N = 127) = 1.512, p = .22) had any significant effect on OS. Conclusions: We did not observe any clear benefit for administering IT MTX to prevent DLBCL relapse in the CNS. Most of the CNS relapse events occurred in the low-risk group, even though 8 patients in the high-risk group did not receive any CNS prophylaxis. This study did not have sufficient power to make a definitive conclusion. As CNS relapse is a rare event, a much larger sample size is required to determine the true efficacy of CNS prophylaxis. Non-GCB cell origin and positive double hit status are not included in the CNS-IPI score but their potential association with risk of DLBCL relapse in the CNS is understudied. Future studies should build upon these findings.

Model for Predicting Central Nervous System Relapse in Diffuse Large B-Cell Lymphoma and Discussion of Prophylaxis Measures

Relapse of the central nervous system (CNS) is a rare but fatal complication in diffuse large B-cell lymphoma (DLBCL). The purpose of this study is to learn how to identify high-risk patients and take effective preventive measures. We retrospectively analyzed 1,290 adult patients with DLBCL at Peking University Cancer Hospital and Shanxi Bethune Hospital between 2010 and2020. There were 55 patients with CNS relapse who had a median follow-up of 5years. The risk of CNS relapse was 1.58% in the low-risk group, 5.66% in the moderate-risk group, and 11.67% in the high-risk group based on CNS International Prognostic Index (CNS-IPI). We found that CNS-IPI and testicular involvement were risk factors for CNS relapse, with OR 1.913 (95% CI: 1.036∼3.531; P= 0.038) versus. OR 3.526 (95% CI: 1.335∼9.313; P= 0.011), respectively. Intrathecal MTX and/or cytarabine prophylaxis was used in 166 patients (13.94%), intravenous (IV) high-dose methotrexate (HD-MTX) prophylaxis in 8 patients (0.67%), and intrathecal plus intravenous prophylaxis in 15 patients (1.26%). There was no significant difference in CNS relapse risk between IT, HD-MTX, and no prophylaxis recipients (12.7% vs. 0% vs. 23.6%, respectively, P=0.170). The risk of CNS relapse was similar whether or not patients accepted prophylaxis (5-year risk 4.1% vs. 2.2%, P= 0.140). Central nervous system (CNS) relapse isassociated with high risk CNS-IPI and testicular involvement. Therefore, it is necessary to pursue novel prophylactic strategies for CNS relapse.

Risk reduction of CNS relapse in diffuse large B cell lymphoma with intrathecal methotrexate prophylaxis: A single institution retrospective study.

e19531 Background: Central nervous system (CNS) relapse is an infrequent but serious and challenging complication in diffuse large B-cell lymphoma (DLBCL) that carries a dismal prognosis. While several risk factors have been identified to stratify the risk for CNS relapse including the 2015 CNS internal Prognostic index (CNS-IPI), controversy still remains regarding the indication, timing, and method of CNS prophylaxis. The purpose of this study was to determine whether IT-MTX reduced the risk of CNS relapse, as well as treatment related and financial toxicity of CNS prophylaxis. Methods: We performed a single-center, retrospective analysis on a cohort of 192 patients with DLBCL who had received treatment between January 2010- August 2022. Patients were identified by using ICD10 code diagnosis in the electronic medical records system. We included patients of all stages of disease and CNS-IPI scores along with patients with testis, breast, sinus, and bone marrow extranodal involvement. Patients with primary CNS disease and primary mediastinal disease were excluded from the study. Clinical data collected by chart review included age at time of diagnosis, sex, performance status, LDH level, disease stage, number and type of therapies administered including IT-MTX, extranodal involvement, MYC/BCL2/BCL6 translocation status, HIV status, cell of origin (COO), treatment response. Toxicities and complications thought to be associated with IT-MTX prophylaxis were also documented in addition to total costs of treatment for each patient. Patient characteristics were compared using Fisher exact test or Pearson’s chi-square test. Results: In patients with intermediate to high CNS relapse risk (CNS-IPI 2-5) IT-MTX did not reduce the 1 year risk of CNS relapse (RR 1.1296, 95% CI 0.1933 to 6.6012, P = 0.08924). The median time to CNS relapse was longer in patients who had received IT-MTX (13.5 months) vs those who did not (7 months). Thirty eight (52.8%) patients reported adverse side effects of any kind as a result of IT-MTX administration, with 23.6% of patients developing grade 2-3 adverse events. The average cost for CNS-prophylaxis was estimated to be approximately $8,059.04 over a patient’s treatment course, but as high as $20,140. Conclusions: In conclusion, our study highlights the necessity to develop improved standardized guidelines for use of CNS prophylaxis in patients with DLBCL. The results from our retrospective study add to the growing body of literature showing IT-MTX has limited and potentially transient effectiveness in preventing CNS relapse. Given the high rate of side effects and significant cost of IT-MTX, we recommend that clinicians carefully consider the risks and benefits of prophylaxis before prescribing IT-MTX for CNS-prophylaxis.

CNS RELAPSE OF DIFFUSE LARGE B‐CELL LYMPHOMA AND ROLE OF UPFRONT PROPHYLAXIS: A 10‐YEAR SINGLE CENTER EXPERIENCE

Introduction: Central nervous system (CNS) relapse of diffuse large B-cell lymphoma (DLBCL) is a rare event, occurring in about 5% of patients (pts) and correlating with a very dismal prognosis. Much debate has surrounded the use of strategies to avert CNS disease recurrence. Nowadays, CNS prophylaxis is mostly based on high-dose intravenous (iv) methotrexate (HD-MTX), but its effectiveness is controversial. Our study focuses on pts with CNS relapse of DLBCL in order to evaluate their clinical and biological features, the validity of known prognostic scores, the efficacy of CNS prophylaxis, prognosis and treatment at the time of relapse. Methods: All pts with DLBCL diagnosed between January 2010 and December 2021 at AOU Città della Salute e della Scienza di Torino and treated with curative intent were selected: 498 cases with at least 12 months of follow-up were identified. Pts with primary mediastinal lymphoma, primary testicular lymphoma or CNS disease at diagnosis were excluded. Results: The case series included 406 pts. Mean age was 67 years, 56/400 had ECOG PS ≥ 2 (14%), 231/400 elevated LDH levels (58%), 251/404 were stage IV (62%), 192/374 IPI score ≥ 3 (51%), 189/373 CNS-IPI 2–3 (51%), 91/373 CNS-IPI 4–6 (24%). 95/397 pts received CNS prophylaxis (24%): 59 by intrathecal (IT) route only (15%) (n 26 CNS-IPI 2-3; n 29 CNS-IPI 4-6), 25 by iv MTX only (6%) (n 17 HD-MTX ≥3 g/mq; n 6 CNS-IPI 2-3; n 16 CNS-IPI 4-6), and 11 by combined route (3%) (n 5 CNS-IPI 2-3, n 6 CNS-IPI 3–6). 12 pts experienced CNS relapse; 8/12 exclusively CNS and 4/12 along with systemic recurrence. The cumulative incidence at 3 years was 2.8%. In univariate analysis CNS relapse risk was significantly influenced by ECOG PS and elevated LDH levels, while the use of prophylaxis was not shown to impact the risk of CNS recurrence. However, none of the pts who received systemic MTX prophylaxis had subsequent CNS disease, while 2/59 pts who received exclusive IT prophylaxis had CNS relapse with an incidence superimposable to the whole cohort (3.3%). In multivariate analysis, only ECOG PS confirmed significant correlation with the risk of such disease recurrence (Figure 1). With a mean follow-up of 36 months, the 3-year overall survival for pts with SNC recurrence was 30%. Encore Abstract—previously submitted to EHA 2023 Keyword: aggressive B-cell non-Hodgkin lymphoma No conflicts of interests pertinent to the abstract.

Risk assessment and prophylactic treatment strategies for central nervous system relapse of diffuse large B-cell lymphoma

Rituximab treatment significantly improved the outcomes of diffuse large B-cell lymphoma (DLBCL). A central nervous system (CNS) relapse remains a serious and fatal event for patients with DLBCL; therefore, the clinical question of the optimal treatment regimen for reducing the risk of CNS relapse remains unknown. The CNS-International Prognostic Index was identified as a predictive model for CNS relapse. No factors can completely predict CNS relapse although several reports regarding high-risk factors for CNS relapse have been reported. In practice, intrathecal methotrexate (MTX) and high-dose MTX therapy have been used for CNS prophylaxis. Unfortunately, evidence of the optimal therapy for CNS prophylaxis in patients with DLBCL remains lacking. This study aimed to review CNS relapse assessment and discuss study results with clinical impacts on CNS prophylaxis treatment strategies in DLBCL.

CNS prophylaxis in aggressive B-cell lymphoma

The prevention of central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) continues to be one of the most contentious areas of lymphoma management. Outcomes for patients with secondary CNS lymphoma (SCNSL) have historically been very poor. However, in recent years improved responses have been reported with intensive immunochemotherapy approaches, and there is a growing interest in potential novel/cellular therapies. Traditional methods for selecting patients for CNS prophylaxis, including the CNS International Prognostic Index, are hampered by a lack of specificity, and there is accumulating evidence to question the efficacy of widely employed prophylactic interventions, including intrathecal and high-dose methotrexate (HD-MTX). Given the potential toxicity of HD-MTX in particular and the ongoing need to prioritize systemic disease control in high-risk patients, there is an urgent need to develop more robust methods for identifying patients at highest risk of CNS relapse, as well as investigating prophylactic interventions with greater efficacy. Here we review new evidence in this field from the last 5 years, focusing on the potential use of molecular diagnostics to improve the identification of high-risk patients, recent large data sets questioning the efficacy of HD-MTX, and the current approach to management of patients with SCNSL. We provide a suggested algorithm for approaching this very challenging clinical scenario.