Radiotherapy for early stage diffuse large B-cell lymphoma with or without double or triple hit genetic alterations

A MYC-rearrangement is a negative prognostic factor in stage II, but not in stage I diffuse large B-cell lymphoma

MYC oncogene rearrangements (MYC-R) negatively affect survival in patients with Ann Arbor stage III-IV diffuse large B-cell lymphoma (DLBCL), but their impact in limited stage (LS) I-II is unclear. Therefore, we assessed the impact of MYC-R on progression-free survival (PFS) and overall survival (OS) in LS DLBCL patients at the population level. We identified 1,434 LS DLBCL patients with known MYC-R status diagnosed between 2014 and 2020, who received R-CHOP(-like) regimens using the Netherlands Cancer Registry, with survival follow-up until February 2022. Stage I patients with (n = 83, 11%) and without (n = 650, 89%) a MYC-R had similar 2-years PFS (89% and 93%, p = 0.63) and OS (both 95%, p = 0.22). Conversely, stage II DLBCL patients with a MYC-R (n = 90, 13%) had inferior survival outcomes compared to stage II patients without a MYC-R (n = 611, 87%) (PFS 70% vs. 89%, p = 0.001; OS 79% vs. 94%, p < 0.0001). Both single MYC-R (single hit, n = 36) and concurrent BCL2 and/or BCL6 rearrangements (double/triple hit, n = 39) were associated with increased mortality and relapse risk. In conclusion, in stage II DLBCL a MYC-R is negatively associated with survival. In stage I DLBCL, however, survival outcomes are excellent irrespective of MYC-R status. This challenges the diagnostic assessment of MYC-R in stage I DLBCL patients.

Evolution of therapy for limited stage diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL), with limited-stage DLBCL defined as stage I or II disease. Risk stratification, initial treatment options, and relapse patterns are distinct from advanced-stage DLBCL, but there is limited data on the impact of biologic features on outcome. Patients have excellent outcomes, with ~90% survival at 2 years. Over the past several years, sequential prospective trials and large registry studies have evaluated the optimal number of chemotherapy cycles and implemented PET-adapted approaches to reduce the need for radiotherapy. Special consideration must still be given to cases of bulky disease, extranodal disease, fully resected scenarios, and adverse biologic features such as high-grade B-cell lymphoma with double/triple hit rearrangements. This review presents the evolution of a modern management approach, with a discussion of recent treatment-defining studies.

Salvage radiotherapy for primary refractory and relapsed diffuse large B-Cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma, accounting for 30-40% of all non-Hodgkin lymphoma cases and presenting later in life, most often in the sixth decade. Although DLBCL is curable, long-term remission rates are only 60-80%. The most recent major advance in upfront therapy for DLBCL was the monoclonal anti-CD20 antibody rituximab, which was approved in the late 1990s; now, 25 years later, up to 40% of patients will experience primary refractory or relapsed disease, thereby underscoring the importance of salvage therapy. Radiation therapy can be highly effective in DLBCL, both initially as consolidation therapy and later as salvage therapy and is currently being explored in the context of immune and cellular therapies. The aim of this review is to examine the therapeutic approaches for relapsed or refractory DLBCL, with a focus on whether using radiation therapy as salvage therapy can improve the likelihood of cure.

Prognostication of Primary Tumor Location in Early-Stage Nodal Diffuse Large B-Cell Lymphoma: An Analysis of the SEER Database

The prognostic role of primary tumor location for clinical outcomes of patients with early-stage nodal diffuse large B-cell lymphoma (DLBCL) remains uncertain. We evaluated the relationship between primary tumor site and overall survival (OS) in 9738 early-stage nodal DLBCL patients from the Surveillance, Epidemiology, and End Results (SEER) database. The primary site of the tumors was characterized as supradiaphragm and subdiaphragm according to the definition of lymph node distribution in the Ann Arbor staging. The OS was significantly better for patients of the supradiaphragm group (n = 6038) compared to the ones from the subdiaphragm group (n = 3655) (hazard ratio (HR) 1.24; 95%CI: 1.16-1.33; P < 0.001), and it was preserved after propensity score matching (PSM) (HR 1.15; 95% CI: 1.07-1.24; P < 0.001). Gene enrichment analyses demonstrated that the subdiaphragm group has an upregulated extracellular matrix (ECM)-related signaling, which reportedly can promote growth, invasion, and metastasis of the cancer, and downregulated interferon response, which is considered to have anti-tumor function. Our results indicate the two tumor locations (supradiaphragm and subdiaphragm) presented different prognostic implications for the overall survival, suggesting that the tumor's location could serve as a prognostic biomarker for early-stage nodal DLBCL patients.

Radiotherapy for Non-Hodgkin Lymphomas

Radiotherapy (RT) plays a diverse and essential role in the contemporary management of non-Hodgkin lymphoma (NHL) and remains the single most powerful monotherapeutic intervention for both aggressive and indolent subtypes. Over the past decade, there have been significant advancements in radiation oncology practice, which have made modern treatments safer and more conformal. Despite this sophistication and evidence supporting a continued role for RT, numerous data suggest that utilization is on the decline. In this review, we discuss the rationale for RT in 4 commonly encountered scenarios: combined modality therapy for limited-stage aggressive NHL, consolidation therapy for advanced-stage aggressive NHL, and the changing roles of salvage RT for relapsed/refractory NHL in an era of new frontiers such as cellular therapies. We also evaluate current strategies to treat indolent histologies. We conclude with perspectives on how RT for the hematological malignancies may continue to evolve.

Stage I-II diffuse large B-cell lymphoma treated with rituximab and chemotherapy with or without radiotherapy

We set to identify prognostic factors in a retrospective cohort of consecutive patients with stage I-II diffuse large B-cell lymphoma treated with rituximab-chemotherapy with or without radiotherapy from 2001 through 2017 at our institution. We identified 143 patients with median follow-up of 7.7 years. The majority were male (59.4%), had stage II (53.1%), had stage-modified IPI 0-1 (smIPI, 58.1%), and had non-bulky disease (<7 cm, 68.5%). 99 patients (69.2%) received rituximab-chemotherapy followed by radiotherapy, and 44 patients (30.8%) received rituximab-chemotherapy alone. The 5-year progression-free survival (PFS) and overall survival (OS) were 81.2% and 88.9%, respectively. The 5-year PFS for those with smIPI 0-1 versus 2-4 was 89.5% versus 69.7%, respectively (P = 0.005). Bulky disease (≥7 cm) was associated with worse PFS and OS on univariable and multivariable analyses (P < 0.05). Patients with smIPI 0-1 without bulky disease have excellent outcomes. However, patients with smIPI 2-4 or bulky disease have a high risk of progression.

The impact of cell-of-origin, MYC/Bcl-2 dual expression and MYC rearrangement on disease relapse among early stage diffuse large B-cell lymphoma patients treated with combined modality therapy

We addressed the prognostic impact of cell-of-origin (COO), MYC and Bcl-2 overexpression as well as isolated MYC rearrangement among 111 patients with limited stage diffuse large B-cell lymphoma (DLBCL) treated with consolidative radiation therapy (RT) after a metabolic complete response to immunochemotherapy. With a median follow-up of 31.1 months (95% CI 27.4 - 34.8), 4 relapses occurred. The 3-year progression free survival (PFS), overall survival (OS), and loco-regional relapse free survival (LRFS) for the cohort were 95%, 96%, and 100%, respectively. There were no differences in OS, PFS, or LRFS based on COO or MYC/Bcl-2 dual expression (DE). Similarly, patients with MYC translocations without BCL2 or BCL6 rearrangements did not have worse outcomes. Consolidative RT produced excellent local control, regardless of DLBCL biology, with one late in-field failure.

Positron Emission Tomography-Directed Therapy for Patients With Limited-Stage Diffuse Large B-Cell Lymphoma: Results of Intergroup National Clinical Trials Network Study S1001

PURPOSE

Diffuse large B-cell lymphoma (DLBCL) presents as a limited-stage disease in 25% to 30% of patients, with better overall survival (OS) than that for advanced-stage disease but with continuous relapse regardless of treatment approach. The preferred treatment is abbreviated rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and radiation therapy. On the basis of promising results of positron emission tomography (PET)-directed treatment approaches, we designed a National Clinical Trials Network (NCTN) study to improve outcomes and decrease toxicity.

METHODS

Patients with nonbulky (< 10 cm) stage I/II untreated DLBCL received 3 cycles of standard R-CHOP therapy and underwent a centrally reviewed interim PET/computed tomography scan (iPET). Those with a negative iPET proceeded with 1 additional cycle of R-CHOP, whereas those with a positive iPET received involved field radiation therapy followed by ibritumomab tiuxetan radioimmunotherapy.

RESULTS

Of 158 patients enrolled, 132 were eligible and 128 underwent iPET, which was positive in 14 (11%) of the patients. With a median follow-up of 4.92 years (range, 1.1-7.7 years), only 6 patients progressed and 3 died as a result of lymphoma. Eleven patients died as a result of nonlymphoma causes at a median age of 80 years. The 5-year progression-free survival estimate was 87% (95% CI, 79% to 92%) and the OS estimate was 89% (95% CI, 82% to 94%), with iPET-positive and iPET-negative patients having similar outcomes.

CONCLUSION

To our knowledge, S1001 is the largest prospective study in the United States of limited-stage DLBCL in the rituximab era, with the best NCTN results in this disease subset. With PET-directed therapy, 89% of the patients with a negative iPET received R-CHOP × 4, and only 11% had a positive iPET and required radiation, with both groups having excellent outcomes. The trial establishes R-CHOP × 4 alone as the new standard approach to limited-stage disease for the absolute majority of patients.

Perspectives on chemotherapy for the management of double-hit lymphoma

INTRODUCTION

. Unlike most B-cell lymphomas, they have poor response to standard R-CHOP therapy, tend to quickly develop resistance to cytotoxic chemotherapies, and are associated with higher central nervous system (CNS) infiltration. This can lead to increased risk of relapse and worse prognosis. DHL/THL represent a subset of lymphomas with unmet medical need.

AREA COVERED

The authors present the available data for the current treatment regimens including intensive chemotherapy regimens, hematopoietic stem-cell transplantation (HSCT), and CNS prophylaxis. They also discuss treatment for relapsed disease including targeted therapies.

EXPERT OPINION

There is currently no accepted standard of care for DHL/THL. For frontline therapy, we recommend enrollment in a well-designed clinical trial if possible, otherwise DA-EPOCH-R with CNS prophylaxis is a commonly used first-line therapy. The authors recommend close surveillance for patients achieving complete response, but for those who fail to achieve a complete response, then clinical trials, more aggressive salvage chemotherapy regimens, or cellular therapies are usually considered.

Current perspectives on the treatment of double hit lymphoma

Introduction: Double hit lymphoma (DHL) represents a new diagnostic category with genetic, immunohistochemical and clinical characteristics intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma. Patients with DHL usually experience poor survival after frontline R-CHOP treatment and require alternative therapies. However, the ideal therapeutic options remain undefined. Areas covered: Traditional therapies for the treatment of DHL are discussed, including intensive induction, hematopoietic stem cell transplantation (HSCT), methotrexate CNS-directed prophylaxis, and radiation therapy. The authors further introduce small-molecule inhibitors targeting myc or bcl-2 signaling pathways, chimeric antigen receptor T-cell therapy, programmed death-1 monoclonal antibody and immunomodulatory drugs as novel approaches. Expert opinion: No standard treatment exists for DHL. At present, DA-EPOCH-R exhibits an upfront induction option. Central nervous system prophylaxis with methotrexate is recommended as part of the induction therapy. For those who do not obtain complete remission, HSCT or clinical trials should be considered. Targeted approaches, especially chimeric antigen receptor T-cell therapies and small-molecule inhibitors targeting myc or bcl-2, exhibit the potential of improving outcomes for patients with DHL. High-throughput sequencing is a promising technique both at diagnosis and relapse, in order to predict outcomes and potential novel therapies.