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.

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.

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).

Absolute B cell counts in blood predict long-term response in follicular lymphoma patients treated with rituximab without chemotherapy.

Rituximab monotherapy is widely used for follicular lymphoma. However, there are no established predictors for response or response duration. We analyzed the long-term prognostic relevance of pre-treatment absolute blood counts of lymphocytes with subsets and monocytes in 265 follicular lymphoma patients, uniformly treated with rituximab without chemotherapy, in two Nordic Lymphoma Group trials. There were 265 previously untreated, stage II-IV follicular lymphoma patients with a median follow-up of over 10 years. Absolute B cell counts ≥ median (0.09 × 109/L) were an independent predictor for shorter time to next treatment or death (multivariable analysis P = 0.010). In univariate analysis, absolute monocyte counts ≥ median (0.5 × 109/L) did not correlate with time to next treatment or death, but with inferior overall survival (P = 0.034). Absolute T cell or T cell subset counts were not predictive for outcome. High absolute B cell counts, possibly reflecting circulating lymphoma cells, have an unfavorable impact on time to next treatment or death in patients treated with rituximab without chemotherapy.

The Karolinska experience of autologous stem-cell transplantation for lymphoma: a population-based study of all 433 patients 1994-2016.

BACKGROUND: Autologous stem-cell transplantation (ASCT) is a common treatment for lymphoma but it has some mortality. METHODS: All 433 lymphoma patients who underwent ASCT for lymphoma at Karolinska Huddinge 1994-2016 were investigated, including CD34+ cell amounts, medications, infectious and other complications, intensive care, longitudinal laboratory values, and secondary myeloid neoplasia. RESULTS: The 100-day non-relapse and overall mortalities were 5.6% and 7.2%. Stem-cell harvests < 5 million CD34+ cells/kg correlated with inferior 100-day and long-term survival. Prior to conditioning (93% BEAM), elevated (both 3-9 and ≥ 10 mg/L) C-reactive protein (CRP) and creatinine, and low albumin (but not higher age) predicted inferior higher 100-day survival. Intravenous antibiotics were given to 97% (22% positive blood cultures) and parenteral nutrition to 89%. After 1 year, 86% had normalized hemoglobin. The 5-year risk for secondary myeloid neoplasia was 4.1%, associated with smaller harvests. CONCLUSIONS: Before starting conditioning, patients should have preferably harvested ≥ 5 million CD34+ cells/kg and normal CRP, albumin, and creatinine. It appears safe to transplant patients ≥ 66 years.

Chemotherapeutic intensity and survival differences in young patients with diffuse large B-cell lymphoma: a Swedish Lymphoma Registry study.

Young patients with diffuse large B-cell lymphoma (DLBCL) are variably treated with rituximab combined with cyclophosphamide-doxorubicin-vincristine-prednisone (R-CHOP), CHOP-etoposide (R-CHOEP), and anthracycline-based regimens with the addition of high-dose cytarabine/methotrexate (R-HDA/M). Using the nationwide, population-based Swedish Lymphoma Registry, we evaluated outcome, by treatment and Healthcare Region, in all 751 DLBCL patients aged ≤60 years without central nervous involvement, diagnosed in Sweden between 2007 and 2012. Overall survival was estimated using multivariate Cox analysis. In patients with age-adjusted international prognostic index (aaIPI) ≥ 2, the 5-year overall survival (OS) was 70%, 76% and 85% after R-CHOP, R-CHOEP and R-HDA/M, respectively (P = 0·002); the corresponding estimates were 40%, 55%, and 92% in aaIPI = 3 (P = 0·014). There were large therapeutic differences between Sweden's six Healthcare Regions for aaIPI ≥ 2: three were "Moderate" (more R-CHOP) and three "Intensive" (more R-CHOEP and R-HDA/M). Patients with aaIPI ≥ 2 who were treated in the Intensive Regions, showed better OS (P < 0·00005), particularly those with aaIPI = 3 (5-year OS, 62% vs. 30%; P < 0·00005). There were no regional differences in therapy or survival in patients with aaIPI < 2. We conclude that in younger high-risk patients, survival appears superior after more intensive therapy than R-CHOP.