Comparative outcomes of rituximab-based systemic therapy and splenectomy in splenic marginal zone lymphoma

Marginal zone lymphomas: a consensus practice statement from the Australasian Lymphoma Alliance

Marginal zone lymphomas (MZLs) are a rare, indolent group of non-Hodgkin lymphomas with different diagnostic, genetic and clinical features and therapeutic implications. The most common is extranodal MZL of mucosa-associated lymphoid tissue, followed by splenic MZL and nodal MZL. Patients with MZL generally have good outcomes with long survival rates but frequently have a relapsing/remitting course requiring several lines of therapy. The heterogeneous presentation and relapsing course present the clinician with several diagnostic and therapeutic challenges. This position statement presents evidence-based recommendations in the setting of Australia and New Zealand.

Time Trend Analysis of Splenectomy for Splenic Marginal Zone Lymphoma: Declining Surgery, Promising Survival

BACKGROUND

The purpose of current study was to examine the incidence, characteristics, treatment, and survival of splenic marginal zone lymphoma (SMZL).

METHODS

Using SEER-18 database, patients diagnosed with SMZL between 2000 and 2018 were included. Effect of splenectomy on survival was evaluated after balancing the confounding factors by propensity score matching. Rates of splenectomy and 1-year relative survival were calculated for each year. A logistic regression model identified factors related to splenectomy, and a Cox regression model assessed factors linked to overall survival (OS).

RESULTS

A total of 2790 patients with SMZL were analyzed. The majority were older than 60 years, female, and white. The age-adjusted incidence of SMZL was 0.17/100,000 person-years, with higher incidence in males. Incidence increased by 0.68%/year and peaked at 80-84 years for both genders. The SMZL-specific survival rates at 3 and 5 years were 89.6% and 85.3%, respectively. Meanwhile, the relative survival rates for the same periods were 88.6% and 85.9%, respectively. Splenectomy patients were more likely to be younger, male, and diagnosed with early-stage disease. Despite the decreasing utilization rate of splenectomy from 59.4% in 2000 to 16.2% in 2018, the 1-year relative survival rate remained relatively stable with minor fluctuations over time. Whether or not the patient underwent splenectomy was not found to be a significant prognostic indicator for OS.

CONCLUSIONS

Our study demonstrated a decreasing use of splenectomy but a relatively stable survival in patients with SMZL, highlighting the urgency to better understand the role of splenectomy and its associated outcomes.

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.

The role of splenectomy in management of splenic B-cell lymphomas

INTRODUCTION

Splenic B-cell lymphomas are rare and understudied entities. Splenectomy is frequently required for specific pathological diagnosis in patients with splenic B-cell lymphomas other than classical hairy cell leukemia (cHCL), and can be effective and durable therapy. Our study investigated the diagnostic and therapeutic role of splenectomy for non-cHCL indolent splenic B-cell lymphomas.

METHODS

Observational study of patients with non-cHCL splenic B-cell lymphoma undergoing splenectomy between 1 August 2011 and 1 August 2021 at the University of Rochester Medical Center. The comparison cohort was patients categorized as having non-cHCL splenic B-cell lymphoma who did not undergo splenectomy.

RESULTS

Forty-nine patients (median age 68 years) had splenectomy (SMZL n = 33, HCLv n = 9, SDRPL n = 7) with median follow up of 3.9 years post splenectomy. One patient had fatal post-operative complications. Post-operative hospitalization was ≤ 4 days for 61% and ≤ 10 days for 94% of patients. Splenectomy was initial therapy for 30 patients. Of the 19 patients who had previous medical therapy, splenectomy changed their lymphoma diagnosis in 5 (26%). Twenty-one patients without splenectomy were clinically categorized as having non-cHCL splenic B-cell lymphoma. Nine required medical treatment for progressive lymphoma and of these 3 (33%) required re-treatment for lymphoma progression compared to 16% of patients following first line splenectomy.

CONCLUSION

Splenectomy is useful for the diagnosis of non-cHCL splenic B-cell lymphomas with comparable risk/benefit profile and remission duration to medical therapy. Patients with suspected non-cHCL splenic lymphomas should be considered for referral to a high-volume center with experience in performing splenectomies for definitive diagnosis and treatment.

Treatment of indolent lymphoma

Treatment of indolent lymphoma has improved significantly in recent decades since the advent of rituximab (anti-CD20 monoclonal antibody). Although, some patients with limited disease can be cured with radiation therapy alone, most patients experience disease progression and recurrence during follow-up despite early initiation of treatment. Thus, watch-and-wait is still regarded the standard for asymptomatic patients. Patients with indolent lymphoma have a significant heterogeneity in terms of tumor burden, symptoms (according to anatomical sites) and the need for instant therapy. Therefore, the initiation of treatment and treatment option should be decided with a clear goal in each patient according to the need for therapy and clinical benefits with the chosen treatment. In this review, we cover the current treatment of follicular lymphoma and marginal zone lymphoma.

CD5 expression in marginal zone lymphoma predicts differential response to rituximab or bendamustine/rituximab

We examined outcomes of 244 patients with marginal zone lymphoma (MZL) diagnosed in 2010-2020, of which 25 (10%) expressed CD5. CD5 expression was present in 22% of splenic, 8% of nodal, and 5% of extranodal MZL, and showed frequent blood/bone marrow involvement, elevated lactate dehydrogenase, and TP53 deletions. CD5 expression was not associated with progression-free or overall survival, but it conferred a significantly higher risk of histologic transformation (22% versus 4% at 5 years, p = 0.002). Among patients receiving first-line rituximab monotherapy, CD5 expression was associated with lower response rate (30% versus 77%, p = 0.006), PFS (25% versus 45% at 3 years, p = 0.003) and OS (44% versus 77%, p = 0.010), whereas CD5 status did not significantly affect outcomes of patients receiving bendamustine with rituximab (P for interaction = 0.012 for progression-free survival). CD5-positive MZL may have a propensity to leukemic dissemination, histologic transformation, and may derive benefit from first-line bendamustine/rituximab rather than rituximab alone.

Superior outcome for splenectomised patients in a population-based study of splenic marginal zone lymphoma in Sweden

Splenic marginal zone lymphoma (SMZL) is a rare low-grade B-cell lymphoma where associations with viral hepatitis and autoimmune and inflammatory diseases (AID) have been indicated. We aimed at assessing the prevalence of viral hepatitis and AID at SMZL diagnosis and outcome by treatment in a Swedish population-based study. A total of 277 SMZL patients registered in the Swedish Lymphoma Register in 2007-2017 were included. A history of viral hepatitis was reported in five (2%) patients and AID prior to SMZL in 72/240 (30%) patients. Treatment was given up front for 207 (75%) patients. Splenectomy with or without systemic treatment was performed in 119 (57%) and was associated with statistically significantly better overall survival [hazard ratio, HR = 0·47 (95% confidence interval, CI: 0·23-0·93), P = 0·03] and progression-free survival (HR = 0·55, 95% CI: 0·35-0·86, P = 0·008) compared to non-splenectomised patients in multivariable analyses. The up-front splenectomised group was younger and generally had a lower Ann Arbor stage, but also more frequently B symptoms and high lactate dehydrogenase than the non-splenectomised group. Viral hepatitis and AID history did not affect SMZL outcome. We report high incidence of AIDs and low incidence of viral hepatitis in this population-based study of SMZL. Splenectomy up front was associated with a favourable outcome.

Chemotherapy-Free Management of Follicular and Marginal Zone Lymphoma

Many patients with follicular (FL) or marginal zone lymphoma (MZL) are not eligible to receive immunochemotherapy due to advanced age or comorbidities. Recent innovations in the treatment of these indolent lymphomas provide options for multiple lines of chemotherapy-free management. More research is needed to determine which older patients are best served by a chemotherapy-free approach in the context of geriatric vulnerabilities. In the first line, regardless of disease burden, rituximab monotherapy can provide high rates of disease control with minimal toxicity, while judicious use of brief maintenance extends the duration of response. Radioimmunotherapy using ibritumomab tiuxetan is an effective and safe post-rituximab consolidation for older patients who have <25% bone marrow involvement. The combination of rituximab and lenalidomide, although “chemotherapy-free”, does not improve tolerability over immunochemotherapy. However, studies support lower doses and shorter duration of lenalidomide exposure as a means to improve safety without materially compromising efficacy for older individuals. Extranodal MZL can often be effectively controlled with low-dose radiation therapy, and splenic MZL has excellent outcomes with rituximab monotherapy. For many patients with relapsed FL/MZL, simple retreatment with anti-CD20 antibodies will prove sufficient. Other currently available options for relapsed/refractory disease include ibritumomab tiuxetan, lenalidomide with rituximab, umbralisib as a potentially less toxic PI3K inhibitor, ibrutinib (for MZL), and tazemetostat (for FL, especially with EZH2 mutation). Emerging data with novel forms of immunotherapy (antibody-drug conjugates like polatuzumab vedotin or loncastuximab tesirine; T-cell-engaging bispecific antibodies like mosunetuzumab or epcoritamab; and chimeric antigen receptor CAR T-cells like axicabtagene ciloleucel) suggest that immune-directed approaches can produce very high and potentially durable responses in FL/MZL with limited toxicities, further obviating the need for chemotherapy.

Splenic marginal zone lymphoma: a case report and literature review

BACKGROUND

Splenic marginal zone lymphoma (SMZL) is a rare non-Hodgkin lymphoma, and much little is known about its clinical characteristics and management strategies. Here we present a case of SMZL and review relevant literature to provide a better recognition of this disease entity.

CASE PRESENTATION

A 49-year-old Chinese female was admitted to our hospital with complaints of abdominal distension and acid reflux. Physical examinations and imaging investigations suggested the presence of splenomegaly. Laboratory workups revealed mildly reduced white blood cell count otherwise was not remarkable. The patient underwent splenectomy. Histological examination combined with immunohistochemical analysis of the resected spleen confirmed the diagnosis of SMZL. The patient recovered uneventfully during follow-ups.

CONCLUSIONS

Due to the rarity and unspecific clinical features, SMZL is extremely challenging to be diagnosed preoperatively. Patients with SMZL are generally associated with favorable prognosis. Combining the staging characteristics of non-Hodgkin's lymphoma and splenic primary lymphoma may assist in clinical staging management of SMZL.

Actualités dans les lymphomes à petites cellules non folliculaires

Non-follicular small cell lymphomas include several entities whose clinical and pathological descriptions have been refined in the last 20 years. MALT lymphoma, developed at the expense of lymphoid tissue associated with the mucosa, is usually localized to a given organ, but can also disseminate. Some patients with MALT lymphoma can be treated by eradicating the associated infectious agent, whereas local treatment should be preferred for other cases ; disseminated forms and relapsed patients are eligible for anti-CD20 antibodies associated with cytotoxic agents. Patients with mantle cell lymphoma have benefited from many advances, including the use of cytarabine and bendamustine, anti-CD20 antibodies, intensive treatments (autograft) and recently targeted therapy (ibrutinib, inhibitor or the Bruton tyrosine kinase). Patients with splenic nodal marginal zone lymphomas should be evaluated for different options, of which immunochemotherapy remains important. For all these entities, the implementation of treatments may be delayed by several years for certain groups of patients. Although considered as incurable, the prognosis of these pathologies has improved significantly and the majority of patients will be able to live for many years with often treatment-free intervals.

RIVA - a phase IIa study of rituximab and varlilumab in relapsed or refractory B-cell malignancies: study protocol for a randomized controlled trial

BACKGROUND

Over 12,000 new cases of B-cell malignancies are diagnosed in the UK each year, with diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) being the most common subtypes. Standard frontline therapy consists of immunochemotherapy with a CD20 monoclonal antibody (mAb), such as rituximab, delivered in combination with multi-agent chemotherapy. Despite being considered a treatable and potentially curable cancer, approximately 30% of DLBCL cases will relapse after frontline therapy. Advanced stage FL is incurable and typically has a relapsing and remitting course with a frequent need for re-treatment. Based on supportive preclinical data, we hypothesised that the addition of varlilumab (an anti-CD27 mAb) to rituximab (an anti-CD20 mAb) can improve the rate, depth and duration of the response of rituximab monotherapy in patients with relapsed or refractory B-cell malignancies.

METHODS/DESIGN

Combination treatment of varlilumab plus rituximab, in two different dosing regimens, is being tested in the RIVA trial. RIVA is a two-stage open-label randomised phase IIa design in up to 40 patients with low- or high-grade relapsed or refractory CD20+ B-cell lymphoma. The study is open to recruitment in the UK. Enrolled patients are randomised 1:1 to two different experimental varlilumab to rituximab combinations. The primary objective is to determine the safety and tolerability of the combination and the anti-tumour activity (response) in relapsed or refractory B-cell malignancies. Secondary objectives will include an evaluation of the duration of the response and overall survival. Tertiary translational objectives include assessment of B-cell depletion, changes in immune effector cell populations, expression of CD27 as a biomarker of response and pharmacokinetic properties. Analyses will not be powered for formal statistical comparisons between treatment arms.

DISCUSSION

RIVA will determine whether the combination of rituximab and varlilumab in relapsed or refractory B-cell malignancies is active and safe prior to future phase II/III trials.

TRIAL REGISTRATION

EudraCT, 2017-000302-37. Registered on 16 January 2017. ISRCTN, ISRCTN15025004 . Registered on 16 August 2017.

Distinct clinical characteristics draw a new prognostic model for splenic marginal zone lymphoma in HBV high prevalent region

Splenic marginal zone lymphoma (SMZL) is a rare indolent B-cell neoplasm with hepatitis virus supposed to involve in the pathogenesis. The characteristics of SMZL derived from Caucasia population and high hepatitis C virus (HCV) infection region have been widely investigated, but few was reported in the Eastern population with HBV prevalent region. We analyzed the clinical characteristics, cytogenetic aberrations and prognostic factors in 160 SMZL patients from China. 25 patients (16%) were HBsAg-positive and 54 (34%) patients with resolved HBV infection. IGH gene usage was analyzed in 39 patients. The preferential usages of IGHV genes were IGHV1-2 (26%), followed by IGHV4-34 (18%) and IGHV2-70 (10%). The patients with HBV infection presented biased IGHV-D-J rearrangements and mutational status. Using three independent factors hemoglobin level, HBsAg positivity and complex karyotype, we developed a new hierarchical prognostic model, which showed a better c-index than the previously reported IIL and HPLL scoring systems in SMZL. In conclusion, SMZL in HBV prevalent region have unique clinical and biological characteristics and new prognostic scoring model should be adopted in this population.

Indications and outcome of splenectomy in hematologic disease

Splenectomy is part of the therapeutic arsenal for benign or malignant hematological disorders that constitute the main indication for elective splenectomy. With the development of minimally invasive approaches, and in particular, laparoscopy, as well as the advent of monoclonal antibody therapy, the indications and the outcomes of splenectomy for hematologic disease have changed in recent years. Nonetheless, splenectomy has its place in hemoglobinopathies and hemolytic diseases, improves thrombocytopenia in refractory immune thrombocytopenic purpura, can reverse sequelae linked to voluminous splenomegaly secondary to myelofibrosis, or can be used for diagnostic purposes or for splenomegaly in lymphoproliferative syndromes.

Splenic marginal zone lymphoma: a literature review of diagnostic and therapeutic challenges

Splenic marginal zone lymphoma (SMZL) is a low-grade B-cell non-Hodgkin's lymphoma characterized by massive splenomegaly, moderate lymphocytosis with or without villous lymphocytes, rare involvement of peripheral lymph nodes and indolent clinical course. As a rare disease, with no randomized prospective trials, there is no standard of care for SMZL so far. Splenectomy has been done for many years as an attempt to control disease, but nowadays it has not been encouraged as first line because of new advances in therapy as rituximab, that are as effective with minimal toxicity. Facing these controversies, this review highlights advances in the literature regarding diagnosis, prognostic factors, treatment indications and therapeutic options.

Bacterial Infections Following Splenectomy for Malignant and Nonmalignant Hematologic Diseases

Splenectomy, while often necessary in otherwise healthy patients after major trauma, finds its primary indication for patients with underlying malignant or nonmalignant hematologic diseases. Indications of splenectomy for hematologic diseases have been reducing in the last few years, due to improved diagnostic and therapeutic tools. In high-income countries, there is a clear decrease over calendar time in the incidence of all indication splenectomy except nonmalignant hematologic diseases. However, splenectomy, even if with different modalities including laparoscopic splenectomy and partial splenectomy, continue to be a current surgical practice both in nonmalignant hematologic diseases, such as Immune Thrombocytopenic Purpura (ITP), Autoimmune Hemolytic Anemia (AIHA), Congenital Hemolytic Anemia such as Spherocytosis, Sickle Cell Anemia and Thalassemia and Malignant Hematological Disease, such as lymphoma. Today millions of people in the world are splenectomized. Splenectomy, independently of its cause, induces an early and late increase in the incidence of venous thromboembolism and infections. Infections remain the most dangerous complication of splenectomy. After splenectomy, the levels of antibody are preserved but there is a loss of memory B cells against pneumococcus and tetanus, and the loss of marginal zone monocytes deputed to immunological defense from capsulated bacteria. Commonly, the infections strictly correlated to the absence of the spleen or a decreased or absent splenic function are due to encapsulated bacteria that are the most virulent pathogens in this set of patients. Vaccination with polysaccharide and conjugate vaccines again Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis should be performed before the splenectomy. This practice reduces but does not eliminate the occurrence of overwhelming infections due to capsulated bacteria. At present, most of infections found in splenectomized patients are due to Gram-negative (G-) bacteria. The underlying disease is the most important factor in determining the frequency and severity of infections. So, splenectomy for malignant diseases has the major risk of infections.

Moving towards best practice when using inverse probability of treatment weighting (IPTW) using the propensity score to estimate causal treatment effects in observational studies

The propensity score is defined as a subject's probability of treatment selection, conditional on observed baseline covariates. Weighting subjects by the inverse probability of treatment received creates a synthetic sample in which treatment assignment is independent of measured baseline covariates. Inverse probability of treatment weighting (IPTW) using the propensity score allows one to obtain unbiased estimates of average treatment effects. However, these estimates are only valid if there are no residual systematic differences in observed baseline characteristics between treated and control subjects in the sample weighted by the estimated inverse probability of treatment. We report on a systematic literature review, in which we found that the use of IPTW has increased rapidly in recent years, but that in the most recent year, a majority of studies did not formally examine whether weighting balanced measured covariates between treatment groups. We then proceed to describe a suite of quantitative and qualitative methods that allow one to assess whether measured baseline covariates are balanced between treatment groups in the weighted sample. The quantitative methods use the weighted standardized difference to compare means, prevalences, higher‐order moments, and interactions. The qualitative methods employ graphical methods to compare the distribution of continuous baseline covariates between treated and control subjects in the weighted sample. Finally, we illustrate the application of these methods in an empirical case study. We propose a formal set of balance diagnostics that contribute towards an evolving concept of ‘best practice’ when using IPTW to estimate causal treatment effects using observational data. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Management of the marginal zone lymphomas

Marginal zone lymphomas (MZL) represent around 8 % of all non-Hodgkin lymphomas. During the last decades a number of studies have addressed the mechanisms underlying the disease development. Extranodal MZL lymphoma usually arises in mucosal sites where lymphocytes are not normally present from a background of either autoimmune processes, such as Hashimoto thyroiditis or Sjögren syndrome or chronic infectious conditions. In the context of a persistent antigenic stimulation, successive genetic abnormalities can progressively hit a B-cell clone among the reactive B-cells of the chronic inflammatory tissue and give rise to a MALT lymphoma. The best evidence of an etiopathogenetic link is available for the association between Helicobacter pylori-positive gastritis and gastric MALT lymphoma. Indeed, a successful eradication of this micro-organism with antibiotics can be followed by gastric MALT lymphoma regression in more than 2/3 of cases. Other microbial agents have been implicated in the pathogenesis of MZL arising in the skin (Borrelia burgdorferi), in the ocular adnexa (Chlamydophila psittaci), and in the small intestine (Campylobacter jejuni). The prevalence of hepatitis C virus (HCV) has also been reported higher in MZL patients (particularly of the splenic type) than in the control population, suggesting a possible causative role of the virus. In non-gastric MALT lymphoma and in splenic MZL the role of the antimicrobial therapy is, however, less clear. This review summarizes the recent advances in Marginal Zone Lymphomas, addressing the critical points in their diagnosis, staging and clinical management.

Disparate survival outcomes after front-line chemoimmunotherapy in older patients with follicular, nodal marginal zone and small lymphocytic lymphoma

Using Surveillance, Epidemiology and End Results (SEER)-Medicare data (1996-2010), we compared survival and toxicity outcomes in 6993 patients older than 65 years with follicular (FL), nodal marginal zone (NMZL) and small lymphocytic lymphoma (SLL) receiving front-line therapy with rituximab (R), RCHOP (R, cyclophosphamide, doxorubicin, vincristine, prednisone), RCVP (R, cyclophosphamide, vincristine, prednisone) or R-fludarabine-containing regimens within 3 years from diagnosis. We demonstrated significant heterogeneity by histology after various regimens in multivariable survival models. Compared with RCHOP, overall survival was inferior with fludarabine-based regimens in FL (hazard ratio [HR] 1.53, p = 0.0001) and NMZL (HR 1.88, p = 0.0018). Conversely, in SLL outcomes were similar with any regimen. In NMZL and SLL, survival was not significantly different after single-agent R compared with multi-agent combinations. Choice of front-line chemotherapy may thus impact survival in older patients with indolent lymphomas, and heterogeneity by histology should be accounted for in clinical trials.