The National Swedish Lymphoma Register - a systematic validation of data quality.

BACKGROUND AND PURPOSE: The Swedish Lymphoma Register (SLR) was initiated in the year 2000 with the aim to monitor quality of care in diagnostics, treatment and outcome of all lymphomas diagnosed nationally among adults. Here, we present the first systematic validation of SLR records as a basis for improved register quality and patient care. PATIENTS AND METHODS: We evaluated timeliness and completeness of register records among patients diagnosed with lymphoma in the SLR (n = 16,905) compared with the National Cancer Register for the period 2013-2020. Comparability was assessed through evaluation of coding routines against national and international guidelines. Accuracy of 42 variables was evaluated through re-abstraction of data from medical records among 600 randomly selected patients diagnosed in 2016-2017 and treated across all six Swedish healthcare regions.  Results: Completeness was high, >95% per year for the period 2013-2018, and >89% for 2019-2020 compared to the National Cancer Register. One in four patients was registered within 3 months, and 89.9% within 2 years of diagnosis. Registration instructions and coding procedures followed the prespecified guidelines. Missingness was generally low (<5%), but high for occasional variables, for example, those describing maintenance and consolidative treatment. Exact agreement of categorical variables was high overall (>80% for 24/34 variables), especially for treatment-related data (>80% for 17/19 variables). INTERPRETATION: Completeness and accuracy are high in the SLR, while timeliness could be improved. Finetuning of variable registration guided by this validation can further improve reliability of register reports and advance service to lymphoma patients and health care in the future.

Treatment sequencing and impact of number of treatment lines on survival in follicular lymphoma: A national population-based study.

Follicular lymphoma (FL) is a clinically heterogeneous disease. The need for treatment, treatment sequencing, number of treatment lines, and its association with survival have not been described in a population-based setting. We identified all patients diagnosed with FL in the Swedish Lymphoma register from 2007 to 2014, followed until 2020, with detailed data on progression/relapse, transformation, and 2nd and further lines of therapy. During a median follow-up of 6.8 years, 1226 patients (69%) received 1st systemic treatment, 358 patients (20%) were managed with watch-and-wait (WaW) only, and 188 (10%) patients were treated with radiotherapy and did not require additional therapy during the study period. Among patients starting systemic treatment, 496 (40%), 224 (18%), and 88 (7%) received 2nd-, 3rd-, or 4th-line therapy, respectively. The 10-year cause-specific cumulative incidence of transformation was 13%. Among patients managed with 1st line R-single, R-CHOP, or BR, 54%, 33%, and 29% required 2nd line, respectively. The cumulative probability of starting subsequent treatment within 2 years was 26% after 1st line and 35% after 2nd line treatment. Two-year OS following 1st, 2nd, 3rd, and 4th line systemic treatment was 84%, 70%, 52%, and 36%, respectively, and remained similar when excluding transformations. We conclude that a substantial proportion of FL patients can be managed with WaW for a long period of time, while patients who require multiple treatment lines constitute a group with a large clinical unmet need. These results constitute valuable real-world reference data for FL.

Redirecting NK cells to the lymph nodes to augment their lymphoma-targeting capacity.

CAR-NK cells can induce remission in lymphoma patients. We speculate that the full potential of adoptive NK cell immunotherapy against lymphoma is restricted by their poor lymph node (LN) homing capacity. Here, we have utilized a clinically approved transfection method with the aim of redirecting NK cells to LNs. Electroporation of ex vivo expanded NK cells with mRNAs coding for CCR7, CXCR5, and CD62L resulted in increased in vitro migration towards chemokines and mouse LN-derived supernatant. Following infusion into SCID/Beige mice, modified NK cells showed enhanced LN homing. Importantly, lymphoma patient-derived NK cells were equally well expanded and engineered as healthy donor NK cells, highlighting their translational potential. Additionally, the introduction of high-affinity CD16, together with the homing molecules, also augmented their ADCC capacity against autologous lymphoma cells. Hence, genetic engineering can be utilized to enhance NK cell LN homing. The homing concept may synergize with CAR- or monoclonal/bi-/tri-specific antibody-based approaches.

Biomarker analysis of the ASPEN study comparing zanubrutinib with ibrutinib for patients with Waldenström macroglobulinemia.

ABSTRACT: The phase 3 ASPEN trial (NCT03053440) compared Bruton tyrosine kinase inhibitors (BTKis), zanubrutinib and ibrutinib, in patients with Waldenström macroglobulinemia (WM). Post-hoc biomarker analysis was performed using next-generation sequencing on pretreatment bone marrow samples from 98 patients treated with zanubrutinib and 92 patients treated with ibrutinib with mutated (MUT) MYD88 and 20 patients with wild-type (WT) MYD88 treated with zanubrutinib. Of 329 mutations in 52 genes, mutations in CXCR4 (25.7%), TP53 (24.8%), ARID1A (15.7%), and TERT (9.0%) were most common. TP53MUT, ARID1AMUT, and TERTMUT were associated with higher rates of CXCR4MUT (P < .05). Patients with CXCR4MUT (frameshift or nonsense [NS] mutations) had lower very good partial response (VGPR) and complete response rates (CR; 17.0% vs 37.2%, P = .020) and longer time to response (11.1 vs 8.4 months) than patients with CXCR4WT treated with BTKis. CXCR4NS was associated with inferior progression-free survival (PFS; hazard ratio [HR], 3.39; P = .017) in patients treated with ibrutinib but not in those treated with zanubrutinib (HR, 0.67; P = .598), but VGPR + CR rates were similar between treatment groups (14.3% vs 15.4%). Compared with ibrutinib, patients with CXCR4NS treated with zanubrutinib had a favorable major response rate (MRR; 85.7% vs 53.8%; P = .09) and PFS (HR, 0.30; P = .093). In patients with TP53MUT, significantly lower MRRs were observed for patients treated with ibrutinib (63.6% vs 85.7%; P = .04) but not for those treated with zanubrutinib (80.8% vs 81.9%; P = .978). In TP53MUT, compared with ibrutinib, patients treated with zanubrutinib had higher VGPR and CR (34.6% vs 13.6%; P < .05), numerically improved MRR (80.8% vs 63.6%; P = .11), and longer PFS (not reached vs 44.2 months; HR, 0.66; P = .37). Collectively, patients with WM with CXCR4MUT or TP53MUT had worse prognosis compared with patients with WT alleles, and zanubrutinib led to better clinical outcomes.

Genetic and transcriptomic analyses of diffuse large B-cell lymphoma patients with poor outcomes within two years of diagnosis.

Despite the improvements in clinical outcomes for DLBCL, a significant proportion of patients still face challenges with refractory/relapsed (R/R) disease after receiving first-line R-CHOP treatment. To further elucidate the underlying mechanism of R/R disease and to develop methods for identifying patients at risk of early disease progression, we integrated clinical, genetic and transcriptomic data derived from 2805 R-CHOP-treated patients from seven independent cohorts. Among these, 887 patients exhibited R/R disease within two years (poor outcome), and 1918 patients remained in remission at two years (good outcome). Our analysis identified four preferentially mutated genes (TP53, MYD88, SPEN, MYC) in the untreated (diagnostic) tumor samples from patients with poor outcomes. Furthermore, transcriptomic analysis revealed a distinct gene expression pattern linked to poor outcomes, affecting pathways involved in cell adhesion/migration, T-cell activation/regulation, PI3K, and NF-κB signaling. Moreover, we developed and validated a 24-gene expression score as an independent prognostic predictor for treatment outcomes. This score also demonstrated efficacy in further stratifying high-risk patients when integrated with existing genetic or cell-of-origin subtypes, including the unclassified cases in these models. Finally, based on these findings, we developed an online analysis tool ( https://lymphprog.serve.scilifelab.se/app/lymphprog ) that can be used for prognostic prediction for DLBCL patients.

Parsaclisib, a PI3Kδ inhibitor, in relapsed and refractory follicular lymphoma (CITADEL-203): a phase 2 study.

Background: Parsaclisib, a potent and highly selective PI3Kδ inhibitor, has shown clinical benefit in patients with relapsed or refractory (R/R) B-cell malignancies. This phase 2 study (CITADEL-203; NCT03126019, EudraCT 2017-001624-22) assessed efficacy and safety of parsaclisib monotherapy in patients with R/R follicular lymphoma (FL). Methods: Patients ≥18 years of age with histologically confirmed R/R FL (grade 1-3a) and prior treatment with ≥2 systemic therapies received parsaclisib 20 mg once daily (QD) for 8 weeks then parsaclisib 20 mg once weekly (weekly dosing group [WG]) or parsaclisib 20 mg QD for 8 weeks then parsaclisib 2.5 mg QD (daily dosing group [DG]); DG was selected for further assessment. Primary endpoint was objective response rate (ORR). Findings: At data cut-off (January 15, 2021), 126 patients had been treated (WG: n = 23; DG: n = 103). ORR (95% confidence interval [CI]) was 77.7% (68.4-85.3) with a complete response rate (95% CI) of 19.4% (12.3-28.4) in DG; median (95% CI) duration of response was 14.7 months (10.4-not estimable [NE]), median progression-free survival was 15.8 months (11.0-NE), and median overall survival was not reached. The most common any-grade treatment-emergent adverse events (TEAEs) among all treated patients included diarrhoea (n = 48, 38.1%), nausea (n = 31, 24.6%), and cough (n = 28, 22.2%); the most common grade ≥3 TEAEs were diarrhoea (n = 15, 11.9%), neutropenia (n = 13, 10.3%), and colitis (n = 7, 5.6%). Dose interruption, reduction, and discontinuation from TEAEs occurred in 46.8% (n = 59), 17.5% (n = 22), and 23.8% (n = 30) of patients, respectively. Interpretation: Treatment with parsaclisib demonstrated rapid and durable responses, and a manageable safety profile in patients with R/R FL. Funding: Incyte Corporation.

Splenic marginal zone lymphoma in Sweden 2000-2020: Increasing rituximab use and better survival in the elderly.

The treatment of splenic marginal zone lymphoma is debated: splenectomy (the old standard-of-care) is better than chemotherapy but maybe not better than rituximab-containing treatment. We examined all 358 patients diagnosed with splenic marginal zone lymphoma in Sweden 2000-2020. The median overall survival was 11.0 years. The median age was 73 years; 61% were women. Age was the only independently prognostic clinical characteristic. Eighty-six patients were started on wait-and-watch, 90 rituximab monotherapy, 47 rituximab-chemotherapy, 88 splenectomy, 37 chemotherapy, and 10 both systemic therapy and splenectomy. Overall survival was inferior in patients treated with chemotherapy, but equal in patients treated with rituximab, rituximab-chemotherapy and splenectomy. Patients treated with both systemic therapy and splenectomy showed good outcome, suggesting that surgery can be safely reserved for nonresponders. After adjustment for age, survival did not differ between patients started on wait-and-watch and those treated with splenectomy or rituximab-containing therapy. Over time, rituximab use and survival increased in patients ≥73 years. This is, to our knowledge, the largest population-based study of splenic marginal zone lymphoma patients treated with upfront rituximab. We conclude that wait-and-watch remains the most reasonable option in asymptomatic splenic marginal zone lymphoma patients. Symptomatic patients should be offered single-agent rituximab in first line.

Zanubrutinib Versus Ibrutinib in Symptomatic Waldenström Macroglobulinemia: Final Analysis From the Randomized Phase III ASPEN Study.

The phase III ASPEN study demonstrated the comparable efficacy and improved safety of zanubrutinib versus ibrutinib in patients with Waldenström macroglobulinemia (WM). Here, we report long-term follow-up outcomes from ASPEN. The primary end point was the sum of very good partial response (VGPR) + complete response (CR) rates; secondary and exploratory end points were also reported. Cohort 1 comprised 201 patients (myeloid differentiation primary response 88-mutant WM: 102 receiving zanubrutinib; 99 receiving ibrutinib); cohort 2 comprised 28 patients (myeloid differentiation primary response 88 wild-type WM: 28 zanubrutinib; 26 efficacy evaluable). At 44.4-month median follow-up, VGPR + CR rates were 36.3% with zanubrutinib versus 25.3% with ibrutinib in cohort 1 and 30.8% with one CR in cohort 2. In patients with CXC motif chemokine receptor 4 mutation, VGPR + CR rates were 21.2% with zanubrutinib versus 10.0% with ibrutinib (cohort 1). Median progression-free survival and overall survival were not reached. Any-grade adverse events (AEs) of diarrhea (34.7% v 22.8%), muscle spasms (28.6% v 11.9%), hypertension (25.5% v 14.9%), atrial fibrillation/flutter (23.5% v 7.9%), and pneumonia (18.4% v 5.0%) were more common with ibrutinib versus zanubrutinib; neutropenia (20.4% v 34.7%) was less common with ibrutinib versus zanubrutinib (cohort 1). Zanubrutinib was associated with lower risk of AE-related treatment discontinuation. Overall, these findings confirm the long-term response quality and tolerability associated with zanubrutinib.

ADAR1-mediated RNA editing promotes B cell lymphomagenesis.

Diffuse large B cell lymphoma (DLBCL) is one of the most common types of aggressive lymphoid malignancies. Here, we explore the contribution of RNA editing to DLBCL pathogenesis. We observed that DNA mutations and RNA editing events are often mutually exclusive, suggesting that tumors can modulate pathway outcomes by altering sequences at either the genomic or the transcriptomic level. RNA editing targets transcripts within known disease-driving pathways such as apoptosis, p53 and NF-κB signaling, as well as the RIG-I-like pathway. In this context, we show that ADAR1-mediated editing within MAVS transcript positively correlates with MAVS protein expression levels, associating with increased interferon/NF-κB signaling and T cell exhaustion. Finally, using targeted RNA base editing tools to restore editing within MAVS 3'UTR in ADAR1-deficient cells, we demonstrate that editing is likely to be causal to an increase in downstream signaling in the absence of activation by canonical nucleic acid receptor sensing.

Δ9-THC and CBD in Plasma, Oral Fluid, Exhaled Breath, and Urine from 23 Patients Administered Sativex.

Background: Detecting the presence of Δ9-THC and CBD is mainly done through venous blood sampling, but other methods are becoming available. Oromucosal administration of Δ9-THC and CBD is less studied than inhalation, but this mode of administration is growing. In this study, we analyze samples obtained through invasive and noninvasive methods in a cohort of patients given oromucosally administered Δ9-THC and CBD to gain understanding in the strengths and weaknesses of the various detection methods. Materials and Methods: Blood, oral fluid (OF), exhaled breath, and urine were collected at several time points from 23 cannabis-naive patients after receiving a single dose of Sativex®; dose ranges: Δ9-THC, 2.7-18.9 mg; CBD 2.5-17.5 mg. Detection of Δ9-THC and CBD was done using liquid chromatography-mass spectrometry methods. Results: Δ9-THC and CBD were present in plasma, OF, and exhaled breath in all 23 patients. The detection time of Δ9-THC and CBD in OF and exhaled breath was longer than in blood. Urine analysis detected the Δ9-THC carboxy metabolite (THC-COOH) up to 7 days after administration, also in a patient who received 8.1/7.5 mg Δ9-THC/CBD. Conclusion: Time to detection of cannabinoids in blood samples was shorter than in exhaled breath and OF. Relative ease of sample collection combined with high sensitivity makes OF and exhaled breath specimens a valuable addition when samples are handled correctly. Δ9-THC metabolites were detected for an unexpected long period of time in urine. EudraCT Number: 2014-005553-39. Date of registration, December 29, 2015.

2-Arachidonoylglycerol Modulates CXCL12-Mediated Chemotaxis in Mantle Cell Lymphoma and Chronic Lymphocytic Leukemia.

To survive chemotherapy, lymphoma cells can relocate to protective niches where they receive support from the non-malignant cells. The biolipid 2-arachidonoylglycerol (2-AG), an agonist for the cannabinoid receptors CB1 and CB2, is released by stromal cells in the bone marrow. To investigate the role of 2-AG in lymphoma, we analyzed the chemotactic response of primary B-cell lymphoma cells enriched from peripheral blood of twenty-two chronic lymphocytic leukemia (CLL) and five mantle cell lymphoma (MCL) patients towards 2-AG alone and/or to the chemokine CXCL12. The expression of cannabinoid receptors was quantified using qPCR and the protein levels visualized by immunofluorescence and Western blot. Surface expression of CXCR4, the main cognate receptor to CXCL12, was analyzed by flow cytometry. Phosphorylation of key downstream signaling pathways activated by 2-AG and CXCL12 were measured by Western blot in three MCL cell lines and two primary CLL samples. We report that 2-AG induces chemotaxis in 80% of the primary samples, as well as 2/3 MCL cell lines. 2-AG induced in a dose-dependent manner, the migration of JeKo-1 cell line via CB1 and CB2. 2-AG affected the CXCL12-mediated chemotaxis without impacting the expression or internalization of CXCR4. We further show that 2-AG modulated p38 and p44/42 MAPK activation. Our results suggest that 2-AG has a previously unrecognized role in the mobilization of lymphoma cells by effecting the CXCL12-induced migration and the CXCR4 signaling pathways, however, with different effects in MCL compared to CLL.

Survival by First-line Treatment Type and Timing of Progression Among Follicular Lymphoma Patients: A National Population-based Study in Sweden.

In follicular lymphoma (FL), progression of disease ≤24 months (POD24) has emerged as an important prognostic marker for overall survival (OS). We aimed to investigate survival more broadly by timing of progression and treatment in a national population-based setting. We identified 948 stage II-IV indolent FL patients in the Swedish Lymphoma Register diagnosed 2007-2014 who received first-line systemic therapy, followed through 2020. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated by first POD at any time during follow-up using Cox regression. OS was predicted by POD using an illness-death model. During a median follow-up of 6.1 years (IQR: 3.5-8.4), 414 patients experienced POD (44%), of which 270 (65%) occurred ≤24 months. POD was represented by a transformation in 15% of cases. Compared to progression-free patients, POD increased all-cause mortality across treatments, but less so among patients treated with rituximab(R)-single (HR = 4.54, 95% CI: 2.76-7.47) than R-chemotherapy (HR = 8.17, 95% CI: 6.09-10.94). The effect of POD was similar following R-CHOP (HR = 8.97, 95% CI: 6.14-13.10) and BR (HR = 10.29, 95% CI: 5.60-18.91). The negative impact of POD on survival remained for progressions up to 5 years after R-chemotherapy, but was restricted to 2 years after R-single. After R-chemotherapy, the 5-year OS conditional on POD occurring at 12, 24, and 60 months was 34%, 46%, and 57% respectively, versus 78%, 82%, and 83% if progression-free. To conclude, POD before but also beyond 24 months is associated with worse survival, illustrating the need for individualized management for optimal care of FL patients.

Immune Biomarkers in the Peripheral Blood and Tumor Microenvironment of Classical Hodgkin Lymphoma Patients in Relation to Tumor Burden and Response to Treatment.

In classical Hodgkin lymphoma (cHL), the malignant cells represent only a small fraction of the tumor. Yet, they orchestrate a lymphocyte-dominated tumor microenvironment (TME) that supports their survival and growth. The systemic effects of this local immunomodulation are not fully elucidated. Here, we aimed at characterizing circulating lymphocytes and plasma proteins in relation to clinical parameters and treatment effect. Peripheral blood (PB) samples were obtained from 48 consecutive patients at diagnosis and at 2 time points after successful primary treatment. Single-cell suspensions were prepared from lymph node (LN) biopsies obtained for routine diagnostic purposes. Twenty healthy individuals were included as controls. Cells from PB and LN were analyzed by flow cytometry, and plasma proteins by Proximity Extension Assay. We found that the frequencies of T and B cells positively correlated between the LN and the PB compartments. Compared to controls, cHL patients had higher frequencies of proliferating T cells as well as higher expression of programmed death (PD)-1 and cytotoxic T lymphocyte antigen (CTLA)-4 in circulating T cells, and lower naive T-cell frequencies. Advanced-stage patients had fewer NK cells with a functionally impaired phenotype. Differences in the immune profile were observed in patients with a high tumor burden and with high inflammation, respectively. Most of these deviations disappeared after standard first-line treatment. Patients who received radiotherapy involving the mediastinum had low T-cell counts for a prolonged period. Our findings suggest that the immunomodulation of lymphocytes in the TME of cHL might affect immune biomarkers in the PB.

Impact of COVID-19 on patients treated with autologous hematopoietic stem cell transplantation: A retrospective cohort study.

Objective: To describe how coronavirus disease 2019 (COVID-19) affects patients with hematological malignancies treated with autologous hematopoietic stem cell transplantation (ASCT). Methods: This retrospective observational cohort study includes all patients with hematological malignancies treated with ASCT in Sweden from 1 January 2020 to 31 December 2020. Patients who subsequently tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) until 31 March 2021 were analyzed for morbidity, mortality, need for supportive care, and risk factors related to COVID-19. Results: This study identified 442 patients who underwent ASCT in Sweden in 2020, among whom 20 (4.5%) subsequently tested positive for COVID-19. The overall mortality was 15%, and the COVID-19-related mortality was 10% among the patients who contracted COVID-19. Six (35%) patients were hospitalized, of which four (24%) needed supplementary oxygen and two (12%) needed intensive care. The absolute risk of COVID-19-related mortality was 0.45%. Conclusions: ASCT patients have a higher risk of severe outcome of COVID-19 compared to the normal population. However, the risks of death, inpatient care, oxygen therapy, and intensive care seem lower in this study compared to previous studies, possibly due to fewer mildly ill patients in other studies. The risk of contracting SARS-CoV-2 appears to be comparable to that in the general population. This study suggests that the COVID-19 pandemic is not a strong argument for refraining from ASCT in the case of hematological malignancy.

Sting Is Commonly and Differentially Expressed in T- and Nk-Cell but Not B-Cell Non-Hodgkin Lymphomas.

The expression patterns of stimulator of interferon genes (STING) were investigated in a cohort of 158 T- and natural killer (NK)-cell and 265 B-cell non-Hodgkin lymphomas (NHLs), as well as in control reactive lymph nodes and tonsils. STING expression was assessed by immunohistochemical methods using diagnostic biopsy specimens obtained prior to treatment. Using an arbitrary 10% cutoff, STING was differentially expressed among T/NK-cell NHLs; positive in 36 out of 38 (95%) cases of ALK+ anaplastic large cell lymphoma (ALCL), 23 out of 37 (62%) ALK-ALCLs, 1 out of 13 (7.7%) angioimmunoblastic T-cell lymphomas, 15 out of 19 (79%) peripheral T-cell lymphomas, not otherwise specified, 20 out of 36 (56%) extranodal NK/T-cell lymphomas of nasal type, 6 out of 7 (86%) T-cell lymphoblastic lymphomas, and 3 out of 4 (75%) mycosis fungoides. STING expression did not correlate with clinicopathological parameters or outcome in these patients with T/NK-cell lymphoma. By contrast, all 265 B-cell NHLs of various types were STING-negative. In addition, STING mRNA levels were very high in 6 out of 7 T-cell NHL cell lines, namely, ALK+ and ALK-ALCL cell lines, and very low or undetectable in 7 B-cell NHL cell lines, suggesting transcriptional downregulation of STING in neoplastic B-cells. At the protein level, using Western blot analysis and immunohistochemistry performed on cell blocks, STING expression was found to be restricted to T-cell NHL cell lines. Taken together, STING expression represents a novel biomarker and therapeutic target in T- and NK-cell lymphomas with direct immunotherapeutic implications since modulators of cGAS-STING activity are already available for clinical use.

Clinical effects of a single dose of cannabinoids to patients with chronic lymphocytic leukemia.

This phase II clinical trial investigates a one-time oromucosal dose of tetrahydrocannabinol/cannabidiol (THC/CBD) in 23 patients with indolent leukemic B cell lymphomas. Primary endpoint was a significant reduction in leukemic B cells. Grade 1 - 2 adverse events were seen in 91% of the patients; most common were dry mouth (78%), vertigo (70%), and somnolence (43%). After THC/CBD a significant reduction in leukemic B cells (median, 11%) occurred within two hours (p = .014), and remained for 6 h without induction of apoptosis or proliferation. Normal B cells and T cells were also reduced. CXCR4 expression increased on leukemic cells and T cells. All effects were gone by 24 h. Our results show that a single dose of THC/CBD affects a wide variety of leukocytes and only transiently reduce malignant cells in blood. Based on this study, THC/CBD shows no therapeutic potential for indolent B cell lymphomas (EudraCT trial no. 2014-005553-39).

Clinical and biological impact of SAMHD1 expression in mantle cell lymphoma.

SAMHD1 is a deoxynucleoside triphosphate triphosphohydrolase (dNTPase) that restricts viral replication in infected cells and limits the sensitivity to cytarabine by hydrolysing its active metabolite, as recently shown in acute myeloid leukemia. Cytarabine is an essential component in the Nordic mantle cell lymphoma protocols (MCL2 and MCL3) for induction and high-dose chemotherapy treatment before autologous stem cell transplantation for younger patients with mantle cell lymphoma (MCL). We here investigated the expression of SAMHD1 in a population-based cohort of MCL (N = 150). SAMHD1 was highly variably expressed in MCL (range, 0.4% to 100% of positive tumor cells). Cases with blastoid/pleomorphic morphology had higher SAMHD1 expression (P = 0.028) and SAMHD1 was also correlated to tumor cell proliferation (P = 0.016). SAMHD1 expression showed moderate correlation to the expression of the transcriptional regulator SOX11 (P = 0.036) but genetic silencing of SOX11 and SAMHD1 by siRNA in MCL cell lines did not suggest mutual regulation. We hypothesized that expression of SAMHD1 could predict short time to progression in patients treated with Cytarabine as part of high-dose chemotherapy. Despite the correlation with known biological adverse prognostic factors, neither low or high SAMHD1 expression correlated to PFS or OS in patients treated according to the Nordic MCL2 or MCL3 protocols (N = 158).

The value of complete remission according to positron emission tomography prior to autologous stem cell transplantation in lymphoma: a population-based study showing improved outcome.

BACKGROUND: Chimeric antigen-receptor T-cell and bispecific antibody therapies will likely necessitate a reconsideration of the role of autologous stem-cell transplantation (ASCT) in lymphoma. Patients who are likely to profit from ASCT need to be better identified. METHODS: Here, we investigated the value of positron emission tomography/computerized tomography (PET/CT) before ASCT. All 521 patients transplanted for lymphoma 1994-2019 at Karolinska (497 conditioned with BEAM) were included. RESULTS: Outcome improved over three calendar periods 1994-2004, 2005-2014, 2015-2019 (2-year overall survival [OS]: 66, 73, 83%; P = 0.018). Non-relapse mortality (NRM) at 100 days over the three periods were 9.8, 3.9, 2.9%, respectively. The OS improvement between 1994 and 2004 and 2005-2014 was due to lower NRM (P = 0.027), but the large OS advance from 2015 was not accompanied by a significant reduction in NRM (P = 0.6). The fraction of PET/CT as pre-ASCT assessment also increased over time: 1994-2004, 2%; 2005-2014, 24%; 2015-2019, 60% (P < 0.00005). Complete responses (PET/CT-CR) were observed in 77% and metabolically active partial responses (PET/CT-PR) in 23%. PET/CT-CR was a predictor for survival in the entire population (P = 0.0003), also in the subpopulations of aggressive B-cell (P = 0.004) and peripheral T-cell (P = 0.024) lymphomas. Two-year OS and progression-free survival (OS/PFS) for patients in PET/CT-CR were in relapsed/refractory aggressive B-cell lymphoma 87%/75% and peripheral T-cell lymphoma 91%/78%. The corresponding figures in PET/CT-PR were 43%/44 and 33%/33%. Patients with solitary PET/CT-positive lesions showed acceptable outcome with ASCT followed by local irradiation (2-year OS/PFS 80%/60%). CT was less discriminative: 2-year OS/PFS: CT-CR, 76%/66%; CT-PR, 62%/51%. Outcome was inferior after BEAC compared with BEAM conditioning. CONCLUSIONS: We conclude that the improved outcome reflects better, PET/CT-informed, identification of patients who should proceed to ASCT. The excellent survival of patients in PET/CT-CR indicates that ASCT should remain part of standard therapy for lymphoma.

The role of BAFF and G-CSF for rituximab-induced late-onset neutropenia (LON) in lymphomas.

Mechanisms for late-onset neutropenia (LON) after rituximab treatment are poorly defined both for non-Hodgkin lymphoma (NHL) and for autoimmune disorders. We performed a case-control analysis of a prospective cohort of 169 evaluable consecutive rituximab-treated NHL patients to assess cytokines involved in neutro- and lymphopoiesis (G-CSF, SDF1, BAFF, APRIL) and inflammation (CRP) as possible LON mechanisms. Fifteen patients (9%) developed LON (peripheral blood /PB/ absolute neutrophil counts /ANC/ < 0.5 G/L, all with marked depletion of CD20+ B-lymphocytes in bone marrows); they were compared with 20 matched NHL controls without LON. At start of LON, significantly higher PB G-CSF and BAFF levels (P = 0.0004 and 0.006, respectively), as well as CRP rises were noted compared to controls; these G-CSF and BAFF and most CRP values returned to levels of the controls in post-LON samples. G-CSF (but not BAFF) changes correlated to CRP rises (but not to ANC levels). BAFF levels correlated significantly to absolute monocyte counts and PB large granular lymphocyte counts (but not to ANC, C-CSF or CRP values). No changes of SDF1 or APRIL levels were noted. Neither LON cases nor controls displayed anti-neutrophil autoantibodies. Collectively, LON in NHL patients was timewise related to transient bursts of blood G-CSF and BAFF concentrations, suggesting that these neutro- and lymphopoiesis growth factors play a role in emergence of rituximab-induced LON, and that inflammation may be a trigger for G-CSF production during LON.

Incidence of relapsed/refractory diffuse large B-cell lymphoma (DLBCL) including CNS relapse in a population-based cohort of 4243 patients in Sweden.

We performed a national population-based study of all patients diagnosed with diffuse large B-cell lymphoma (DLBCL) in Sweden in 2007-2014 to assess treatment intent and risk of relapsed/refractory disease, including central nervous system (CNS) relapse, in the presence of competing risks. Overall, 84% of patients started treatment with curative intent (anthracycline-based) (n = 3550, median age 69 years), whereas 14% did not (n = 594, median age 84 years) (for 2% the intent was uncertain). Patients treated with curative intent had a 5-year OS of 65.3% (95% CI: 63.7-66.9). The median OS among non-curatively treated patients was 2.9 months. The 5-year cumulative incidence of relapsed/refractory disease in curative patients was 23.1% (95% CI: 21.7-24.6, n = 847). The 2-year cumulative incidence of CNS relapse was 3.0% (95% CI: 2.5-3.6, n = 118) overall, and 8.0% (95% CI: 6.0-10.6, n = 48) among patients with high CNS-IPI (4-6), when considering other relapse locations and death as competing events. The incidence of relapsed/refractory DLBCL overall and in the CNS was lower than in previous reports, still one in seven patients was not considered fit enough to start standard immunochemotherapy at diagnosis. These results are important for quantification of groups of DLBCL patients with poor prognosis requiring completely different types of interventions.