Primary mediastinal large B-cell lymphoma: optimal therapy and prognostic factors in 41 consecutive Asian patients

Outcomes after first-line immunochemotherapy for primary mediastinal B-cell lymphoma: a LYSA study

Primary mediastinal B-cell lymphoma (PMBL) is a rare type of aggressive lymphoma typically affecting young female patients. The first-line standard of care remains debated. We performed a large multicenter retrospective study in 25 centers in France and Belgium to describe PMBL patient outcomes after first-line treatment in real-life settings. A total of 313 patients were enrolled and received rituximab (R) plus ACVBP (doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone) (n = 180) or CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) delivered every 14 days (R-CHOP14, n = 76) or 21 days (R-CHOP21, n = 57) and consolidation strategies in modalities that varied according to time and institution, mainly guided by positron emission tomography. Consolidation autologous stem cell transplantation was performed for 46 (25.6%), 24 (31.6%), and 1 (1.8%) patient in the R-ACVBP, R-CHOP14, and R-CHOP21 groups, respectively (P < .001); only 17 (5.4%) patients received mediastinal radiotherapy. The end-of-treatment complete metabolic response rates were 86.3%, 86.8%, and 76.6% (P = .23) in the R-ACVBP, R-CHOP14, and R-CHOP21 groups. The median follow-up was 44 months, and the R-ACVBP, R-CHOP14, and R-CHOP21 three-year progression-free survival probabilities were 89.4% (95% confidence interval [CI], 84.8-94.2), 89.4% (95% CI, 82.7-96.6), and 74.7% (95% CI, 64-87.1) (P = .018). A baseline total metabolic tumor volume (TMTV) ≥360 cm3 was associated with a lower progression-free survival (hazard ratio, 2.18; 95% CI, 1.05-4.53). Excess febrile neutropenia (24.4% vs 5.3% vs 5.3%; P < .001) and mucositis (22.8% vs 3.9% vs 1.8%; P < .001) were observed with R-ACVBP compared with the R-CHOP regimens. Patients with PMBL treated with dose-dense immunochemotherapy without radiotherapy have excellent outcomes. R-ACVBP acute toxicity was higher than that of R-CHOP14. Our data confirmed the prognostic importance of baseline TMTV.

Pembrolizumab in the treatment of refractory primary mediastinal large B-cell lymphoma: safety and efficacy

Introduction: Primary mediastinal large B-cell lymphoma (PMBL) is a rare subtype of lymphoma, clinically and biologically distinct from diffuse large B-cell lymphoma (DLBCL) that shows overlapping features with classical Hodgkin lymphoma (cHL). If first-line strategies lead to 80-85% of curability, relapse occurs early with a chemo-refractory disease and a poor outcome. The presence of 9p24.1 rearrangement, conducting to the overexpression of the immune checkpoint molecules PDL1 and 2, has paved the way for immune checkpoint blockers development in these entities. Pembrolizumab, an anti PD-1 checkpoint antibody, was initially approved in solid cancer and later on in the lymphoma field in cHL.Areas covered: We summarize the biology and clinical need in PMBL, leading to the rationale for checkpoint inhibitors development, as well as pembrolizumab clinical studies in this entity. To do so, we performed a PubMed search using the terms: 'PMBCL,' 'lymphoma,' 'Immune checkpoint,' and 'Pembrolizumab.'Expert opinion: Pembrolizumab showed tolerable safety profile and efficacy data in patients with PMBL who have relapsed after, or are ineligible for autologous stem cell transplant (ASCT). Some combination strategies have shown promising preliminary results, while others are currently being conducted.

Primary Mediastinal B-Cell Lymphoma: A 2021 Update on Genetics, Diagnosis, and Novel Therapeutics

Primary mediastinal large B-cell lymphoma (PMBCL) is an aggressive B-cell lymphoma arising from thymic B-cells having clinicopathologic features distinct from systemic diffuse large B-cell lymphoma (DLBCL). PMBCL comprises 2% to 4% of all non-Hodgkin lymphomas (NHL), 7% of DLBCL and seen predominantly in young females with a median age of 35 years at diagnosis. The annual incidence of PMBCL is 0.4 per million with a 5-year survival rate exceeding 70% with improving supportive care and genetic characterization of the disease. Pathogenesis involves dysregulation of Janus kinase-signal transducer and activator of transcription (JAK-STAT), nuclear factor-kB (NF-kB) pathways and amplification of the 9p24.1 region of chromosome 9. PMBCL patients have a prolonged life expectancy necessitating the need for treatment approaches that are based on maximizing cure with minimal long-term toxicity. Due to rarity and its recognition as a distinct entity, therapeutic decisions are guided by clinical presentation, clinician and center experience, and analysis of patients with PMBCL within DLBCL registries. Historically R-CHOP has been the usual first line treatment for PMBCL followed by involved site radiotherapy (ISRT), however clinical practice varies across centers with emerging consensus to avoid upfront RT by utilizing dose intense regimens (DA-EPOCH-R) in younger and fit patients. Prognosis of relapsed refractory PMBCL not responding to salvage chemotherapy is dismal, however there are many emerging options including Brentuximab Vedotin, immune check point inhibitors and chimeric antigen receptor T-cell therapy. In this article, we focus on the pathogenesis, current and evolving treatments, and provide recommendations for optimal management of patients with PMBCL.

Identification of Very Low-Risk Subgroups of Patients with Primary Mediastinal Large B-Cell Lymphoma Treated with R-CHOP

BACKGROUND

R-CHOP can cure approximately 75% of patients with primary mediastinal large B-cell lymphoma (PMLBCL), but prognostic factors have not been sufficiently evaluated yet. R-da- EPOCH is potentially more effective but also more toxic than R-CHOP. Reliable prognostic classification is needed to guide treatment decisions.

MATERIALS AND METHODS

We analyzed the impact of clinical prognostic factors on the outcome of 332 PMLBCL patients ≤65 years treated with R-CHOP ± radiotherapy in a multicenter setting in Greece and Cyprus.

RESULTS

With a median follow-up of 69 months, 5-year freedom from progression (FFP) was 78% and 5-year lymphoma specific survival (LSS) was 89%. On multivariate analysis, extranodal involvement (E/IV) and lactate dehydrogenase (LDH) ≥2 times upper limit of normal (model A) were significantly associated with FFP; E/IV and bulky disease (model B) were associated with LSS. Both models performed better than the International Prognostic Index (IPI) and the age-adjusted IPI by Harrel's C rank parameter and Akaike information criterion. Both models A and B defined high-risk subgroups (13%-27% of patients [pts]) with approximately 19%-23% lymphoma-related mortality. They also defined subgroups composing approximately one-fourth or one-half of the patients, with 11% risk of failure and only 1% or 4% 5-year lymphoma-related mortality.

CONCLUSION

The combination of E/IV with either bulky disease or LDH ≥2 times upper limit of normal defined high-risk but not very-high-risk subgroups. More importantly, their absence defined subgroups comprising approximately one-fourth or one-half of the pts, with 11% risk of failure and minimal lymphoma-related mortality, who may not need more intensive treatment such as R-da-EPOCH.

IMPLICATIONS FOR PRACTICE

By analyzing the impact of baseline clinical characteristics on outcomes of a large cohort of patients with primary mediastinal large B-cell lymphoma homogeneously treated with R-CHOP with or without radiotherapy, we developed novel prognostic indices which can aid in deciding which patients can be adequately treated with R-CHOP and do not need more intensive regimens such as R-da-EPOCH. The new indices consist of objectively determined characteristics (extranodal disease or stage IV, bulky disease, and markedly elevated serum lactate dehydrogenase), which are readily available from standard initial staging procedures and offer better discrimination compared with established risk scores (International Prognostic Index [IPI] and age-adjusted IPI).

Primary Mediastinal B-Cell Lymphoma: Novel Precision Therapies and Future Directions

Primary mediastinal large B-cell lymphoma (PMBCL) is a distinct clinicopathologic disease from other types of diffuse large B-cell lymphoma (DLBCL) with unique prognostic features and limited availability of clinical data. The current standard treatment for newly diagnosed PMBCL has long been dependent on a dose-intensive, dose-adjusted multi-agent chemotherapy regimen of rituximab plus etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-R-EPOCH). Recent randomized trials have provided evidence that R-CHOP followed by consolidation radiotherapy (RT) is a valuable alternative option to first-line treatment. For recurrent/refractory PMBCL (rrPMBCL), new drugs such as pembrolizumab and CAR-T cell therapy have proven to be effective in a few studies. Positron emission tomography-computed tomography (PET-CT) is the preferred imaging modality of choice for the initial phase of lymphoma treatment and to assess response to treatment. In the future, baseline quantitative PET-CT can be used to predict prognosis in PMBCL. This review focuses on the pathology of PMBCL, underlying molecular basis, treatment options, radiotherapy, targeted therapies, and the potential role of PET-CT to guide treatment choices in this disease.

Addition of rituximab to CHOP-like chemotherapy in first line treatment of primary mediastinal B-cell lymphoma

Background

The addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) -like therapy has improved survival in primary mediastinal B-cell lymphoma (PMBCL) patients. However, these results were obtained in young low risk patients and a reevaluation in an unselected patient cohort is warranted.

Methods

In this study, we analyzed 80 PMBCL patients treated with a CHOP-based regimen with and without rituximab.

Results

In the non-rituximab cohort 10-year progression free survival (PFS) was 67% and 10-year overall survival (OS) was 72% versus a PFS of 95% and a OS of 92% in the rituximab group, PFS P = 0.001, OS P = 0.023. A subgroup PFS analysis by international prognostic index (IPI) risk revealed that all risk groups benefit from addition of rituximab to induction chemotherapy. In addition, OS probability was higher in the group of non-low risk patients who were treated with rituximab compared to those patients who did not receive rituximab (P = 0.035). In multivariate analysis, only addition of rituximab to induction chemotherapy and reaching complete remission (CR) after first line therapy had a beneficial effect on both PFS and OS, whereas IPI, age, upfront high dose (HD) chemotherapy/autologous blood stem cell transplantation (ABSCT) and rituximab maintenance had no impact on survival.

Conclusions

Our data demonstrate a survival benefit in unselected PMBCL patients treated with CHOP-like induction regimen and additional rituximab independently of the IPI risk score.

Fever and arthralgia as the initial symptoms of primary bone marrow diffuse large B-cell lymphoma: A case report

Primary bone marrow diffuse large B-cell lymphoma (DLBCL) is rare, and only a few cases have been reported. Fever and arthralgia as the initial symptom are extremely rare; however, awareness must be made of this presentation. The current study describes the clinical and pathological findings of a 41-year-old man affected by fever and arthralgia. Blood tests revealed leukopenia and anemia. Multiple bone marrow biopsies were conducted and confirmed the diagnosis of primary bone marrow DLBCL. Primary bone marrow DLBCL is a rare and frequently misdiagnosed subset of non-Hodgkin's lymphoma. The current case demonstrates that utility of bone marrow biopsy for diagnosis should not be ignored, and that repeated bone marrow punctures in multiple locations may be necessary.

Favorable outcome of primary mediastinal large B-cell lymphoma patients treated with sequential RCHOP-RICE regimen without radiotherapy

PURPOSE

Outcomes in primary mediastinal B cell lymphoma (PMBL) improved with the introduction of dose intense treatments, consolidation radiotherapy and rituximab. DA-EPOCH-R, which omits radiotherapy has been adopted with worldwide enthusiasm, despite lack of proven superiority in randomized trials. We aimed to evaluate the course and outcome of PMBL using an alternative intensive rituximab-containing regimen, RCHOP-RICE. We also evaluated the prognostic value of (18)FDG-PET-CT (PET-CT).

METHODS

We reviewed the clinical, laboratory and imaging data of PMBL patients receiving 1st-line treatment in Hadassah Medical Center between 8/2002 and 10/2014.

RESULTS

Of 47 PMBL patients, 24 (51 %) were treated with RCHOP-RICE and 23 (49 %) with other protocols. Overall, the 5-year progression-free survival was 93 % and the overall survival was 98 % (87 and 100 %, respectively, for the RCHOP-RICE regimen). Patient characteristics and treatment toxicities were balanced among protocols. A mean of 11.1 ± 1.3 hospitalization days/patient were needed to administer RCHOP-RICE regimen compared to 37 ± 2 days/patient for DA-EPOCH-R (n = 2). Radiotherapy was given to 3 patients (12 %) treated with RCHOP-RICE compared to 18 patients (78 %) treated with other protocols (p < 0.01). For patients followed with interim and end of treatment (EOT) PET-CT, we observed a significant reduction in the uptake between the two (p < 0.0001). Using a Deauville score cutoff of 3, the negative and positive predictive values (NPV and PPV) of EOT PET-CT were 94 and 33 %, respectively.

CONCLUSIONS

The RCHOP-RICE protocol results in excellent survival outcomes, generally permits omission of RT and is simpler to administer than DA-EPOCH-R. Interim PET-CT in PMBL may be unjustified; however, EOT Deauville scores ≤3 predicts a favorable outcome.

Role of radiation therapy in primary mediastinal large B-cell lymphoma in rituximab era: A US population-based analysis

The use of radiation (RT) in primary mediastinal large B-cell lymphoma (PMBCL) may predispose young patients to the risk of cardiopulmonary toxicities and secondary malignancies. We used Surveillance, Epidemiology and End Results (SEER) 18 database to compare the overall survival (OS) differences among adult patients treated with and without RT after rituximab approval in the US. Multivariate analyses were performed using Cox proportional hazards regression to compare OS based on the use of RT while adjusting for age, year of diagnosis, race, stage and gender. PMBCL patients (n = 258), who received RT (48%), were similar in terms of age, gender, race, and stage at diagnosis to patients who did not receive RT. The five year OS was similar between patients treated with versus without RT (82.5% vs. 78.6%, P = 0.47). In a multivariate analysis, the use of RT did not influence OS in the rituximab era (HR 0.83; 95% CI 0.43-1.59; P = 0.56). Rituximab may reduce the benefit of RT in select patients such as those who achieve a metabolic complete remission at the end of chemotherapy.

Primary mediastinal large B-cell lymphoma

The management of primary mediastinal large B-cell lymphoma (PMBCL) requires a balance between optimizing chances of cure and reducing risk of long-term toxicities. The combination of rituximab to cyclophosphamide, doxorubicin, vincristine and prednisone (RCHOP) followed by mediastinal radiation results in a plateau in progression-free survival after first few years of follow-up. In rituximab era, a negative positron emission tomography (PET) scan performed after the completion of immunochemotherapy has a high predictive value for durable remission. Consequently, end-of-therapy PET may be utilizable to avoid radiation without compromising survival. Additionally, intensified chemotherapy alone has shown excellent survival. PMBCL is frequently associated with amplification of programmed death ligand (PDL) 1/2 and constitutive activation of JAK-STAT and NFKB pathways; these may serve as promising therapeutic targets. Clinical trials that integrate novel therapies into upfront immunochemotherapy and utilize end-of-therapy PET scan to guide mediastinal radiation have potential to further enhance survival and prevent long-term toxicities.

Prognostic significance of pleural or pericardial effusion and the implication of optimal treatment in primary mediastinal large B-cell lymphoma: a multicenter retrospective study in Japan

The prognosis of patients with primary mediastinal large B-cell lymphoma has improved over recent years. However, the optimal treatment strategy including the role of radiotherapy remains unknown. We retrospectively analyzed the clinical outcomes of 345 patients with newly diagnosed primary mediastinal large B-cell lymphoma in Japan. With a median follow up of 48 months, the overall survival at four years for patients treated with R-CHOP (n=187), CHOP (n=44), DA-EPOCH-R (n=9), 2(nd)- or 3(rd)-generation regimens, and chemotherapy followed by autologous stem cell transplantation were 90%, 67%, 100%, 91% and 92%, respectively. Focusing on patients treated with R-CHOP, a higher International Prognostic Index score and the presence of pleural or pericardial effusion were identified as adverse prognostic factors for overall survival in patients treated with R-CHOP without consolidative radiotherapy (IPI: hazard ratio 4.23, 95% confidence interval 1.48-12.13, P=0.007; effusion: hazard ratio 4.93, 95% confidence interval 1.37-17.69, P=0.015). Combined with the International Prognostic Index score and the presence of pleural or pericardial effusion for the stratification of patients treated with R-CHOP without radiotherapy, patients with lower International Prognostic Index score and the absence of effusion comprised approximately one-half of these patients and could be identified as curable patients (95% overall survival at 4 years). The DA-EPOCH-R regimen might overcome the effect of these adverse prognostic factors. Our simple indicators of International Prognostic Index score and the presence of pleural or pericardial effusion could stratify patients with primary mediastinal large B-cell lymphoma and help guide selection of treatment.

Primary mediastinal large B-cell lymphoma: Clinical features, prognostic factors and survival with RCHOP in Arab patients in the PET scan era

Objective:

PMBCL is a distinct type of nonhodgkins lymphoma with specific clinicopathological features. To clarify clinical features, treatment alternatives and outcomes, we evaluated 28 Arab patients treated with chemotherapy or radiotherapy between 2006 and 2011.

Patients and Methods:

PMBCL lymphoma patients identified according to WHO classification and treated at KCCC between 2006 and 2011 were included in this study. Demographic and clinical data are presented as means or medians. Overall survival was estimated using the Kaplan-Meier method. Survival rates were compared using the log-rank test. A P < 0.05 was considered significant.

Results:

The median age of the patients was 31 years and the male to female ratio was 2:1. Majority of the patients (75%) presented with stage I/II disease. Most had features of local extension like pleural effusion (18%) and SVCO (39%). Only 11% of the patients had bone marrow involvement at presentation. 96% of the patients required biopsy from the mediastinal mass either by image guided core biopsy (75%) or by surgical biopsy. Most patients were treated by RCHOP and involved field radiotherapy. Patients with positive PET scan after RCHOP chemotherapy received salvage chemotherapy and BEAM autologous marrow transplant. The five year OS for the entire group was 85% while the PFS was 73%. Patients who had PET scan for response evaluation had better OS [P = 0.013] and PFS [P = 0.039] when compared with those patients who received only radiotherapy based on CT scan evaluation.

Conclusion:

PMBCL is a specific lymphoma entity seen in the young with good survival. The role of PET scan for response evaluation and the type of consolidation therapy needs to be further clarified

Treatment of high-risk aggressive B-cell non-Hodgkin lymphomas with rituximab, intensive induction and high-dose consolidation: long-term analysis of the R-MegaCHOP-ESHAP-BEAM Trial

We have studied the feasibility and efficacy of intensified R-MegaCHOP-ESHAP-BEAM therapy in high-risk aggressive B-cell lymphomas. Altogether 105 patients (19-64 years) with diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBL) or follicular lymphoma grade 3 (FL3) with an age-adjusted International Prognostic Index of 2-3 were recruited. Treatment consisted of three cycles of high-dose R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), followed by three cycles of R-ESHAP (rituximab, etoposide, methylprednisolone, cytarabine, cisplatin) and high-dose consolidation with BEAM (BCNU, etoposide, cytarabine, melphalan) and autologous stem cell transplant. The 5-year progression-free survival (PFS) was 72% (DLBCL 60%, PMBL 89%) and overall survival (OS) was 74% (DLBCL 61%, PMBL 89%) after a median follow-up of 85 months. However, an independent prognostic factor was age only, with patients ≤ 45 years having 5-year PFS 90% and patients > 45 years having PFS 54%. PMBL had better prognosis than DLBCL/FL3 in patients > 45 years (PFS, 88% vs. 48%), but not in younger patients (PFS, 91% vs. 94%).

Primary mediastinal large B-cell lymphoma: a single-center experience in Korea

BACKGROUND

Primary mediastinal large B-cell lymphoma (PMBL) is a distinct subtype of non-Hodgkin lymphoma, which has no consensus for its ideal treatment or prognosis.

METHODS

We reviewed the clinicopathologic features and clinical outcomes of 25 PMBL cases diagnosed at a single institution between 1993 and 2009 and compared them with 588 cases of non-mediastinal, diffuse large B-cell lymphoma (DLBCL, control group) diagnosed during the same period.

RESULTS

Thirteen (52.0%) PMBL patients had Ann Arbor stage III or IV disease, and 10 (40.0%) had B symptoms. Thirteen (52%) PMBL patients were classified as high-intermediate/high-risk according to the International Prognostic Index. There was a significant prevalence of young (median: 31 years; range, 15-78 years; P<0.001), female (68%; P=0.014) patients in the PMBL group compared to the control group (median: 56 years; range, 15-85 years; 43.2% female). Bulky disease and elevated levels of lactate dehydrogenase (LDH) were more frequent in the PMBL group (P<0.001 and P=0.003, respectively). Nineteen (76%) PBML patients achieved complete remission, and 18 were alive at the last follow-up (median: 43 months; range, 1-92 months). There was no difference in the 3-year, overall survival rate (72%, 95% confidence interval [CI]: 54.0-83.0 versus 70.1%, 95% CI, 109.0-126.0; P=0.686) between PMBL and control patients, respectively.

CONCLUSION

Compared to patients with non-mediastinal DLBCL, Korean patients with PMBL are predominantly young women with bulky disease and high LDH levels but with no significant difference in survival.

Prognostic significance of rituximab and radiotherapy for patients with primary mediastinal large B-cell lymphoma receiving doxorubicin-containing chemotherapy

Abstract The aim of this study was to evaluate the prognostic importance of rituximab and radiotherapy in patients with primary mediastinal large B-cell lymphoma (PMBCL) receiving doxorubicin-containing chemotherapy. Seventy-nine patients with PMBCL received CHOP chemotherapy with (n = 39) or without rituximab (n = 40), and 60 patients received additional radiotherapy. Patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) had significantly superior survival rates. The 5-year overall survival (OS) and progression-free survival (PFS) rates were 83.7% and 76.7% for R-CHOP, compared with 48.3% (p = 0.011) and 44.2% (p = 0.012) for CHOP, respectively. Similarly, the 5-year OS and PFS rates for early stage patients were 93.8% and 84.6% with R-CHOP, and 52.0% (p = 0.002) and 46.6% (p = 0.003) with CHOP, respectively. Patients treated with chemotherapy and radiotherapy had better survival and local control (LC) rates compared with chemotherapy alone. The 5-year OS, PFS and LC rates for early stage patients were 73.6%, 69.9% and 92.6% for chemotherapy and radiotherapy, and 50.8% (p = 0.076), 36.9% (p = 0.008) and 56.4% (p < 0.001) for chemotherapy alone, respectively. Early stage patients treated with R-CHOP and radiotherapy had 5-year OS, PFS and LC rates of 96.4%, 85.9% and 93.1%. R-CHOP plus consolidation radiotherapy was associated with excellent survival and LC rates.

Noncoplanar intensity-modulated radiation therapy for young female patients with mediastinal lymphoma

The purpose of this study is to apply noncoplanar intensity‐modulated radiation therapy (Nonco_IMRT) to young female patients with mediastinal lymphoma. Nonco_IMRT was evaluated through a planning comparison study with coplanar IMRT (Co_IMRT) and conventional anteroposterior and posteroanterior fields (AP–PA) plans. Co_IMRT was performed with five equally spaced beams starting from a gantry angle of 216°. Nonco_IMRT used two noncoplanar beams in the sagittal plane to replace the Co_IMRT beams that directly irradiated the breasts. Nineteen young female patients were enrolled in the retrospective study. Dose coverage of the planning target volume (PTV) and the dose delivered to organs at risk (OARs) were analyzed. For all patients, PTV coverage and heart V30 were similar between the two IMRT techniques (p < 0.05). Compared to Co_IMRT, the mean dose delivered and regions receiving a low radiation dose were significantly reduced for bilateral breasts and lungs in Nonco_IMRT (p < 0.05). Breast V5 and lung V5 were relatively reduced by 21% and 12%, respectively. Compared with the conventional AP–PA plan, Nonco_IMRT had better PTV coverage and OARs sparing, except for being larger in V5 to breast and lung. In IMRT for young female patients with mediastinal lymphoma, using of Nonco_IMRT significantly reduces the radiation dose to the breasts and lungs compared with Co_IMRT, and consequently reduces the risk of breast second cancer and pulmonary toxicity. Besides young female patients, Nonco_IMRT can also benefit other mediastinal lymphoma patients.

PACS number: 87.55.D‐