Current and emerging treatment options in primary mediastinal B-cell lymphoma

Lung cancer statistics, 2023

Despite decades of declining mortality rates, lung cancer remains the leading cause of cancer death in the United States. This article examines lung cancer incidence, stage at diagnosis, survival, and mortality using population-based data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. Over the past 5 years, declines in lung cancer mortality became considerably greater than declines in incidence among men (5.0% vs. 2.6% annually) and women (4.3% vs. 1.1% annually), reflecting absolute gains in 2-year relative survival of 1.4% annually. Improved outcomes likely reflect advances in treatment, increased access to care through the Patient Protection and Affordable Care Act, and earlier stage diagnosis; for example, compared with a 4.6% annual decrease for distant-stage disease incidence during 2013-2019, the rate for localized-stage disease rose by 3.6% annually. Localized disease incidence increased more steeply in states with the highest lung cancer screening prevalence (by 3%-5% annually) than in those with the lowest (by 1%-2% annually). Despite progress, disparities remain. For example, Native Americans have the highest incidence and the slowest decline (less than 1% annually among men and stagnant rates among women) of any group. In addition, mortality rates in Mississippi and Kentucky are two to three times higher than in most western states, largely because of elevated historic smoking prevalence that remains. Racial and geographic inequalities highlight longstanding opportunities for more concerted tobacco-control efforts targeted at high-risk populations, including improved access to smoking-cessation treatments and lung cancer screening, as well as state-of-the-art treatment.

Prognostic factors and clinical survival outcome in patients with primary mediastinal diffuse large B-cell lymphoma in rituximab era: A population-based study

The goal of this study was to investigate the clinical characteristics, prognostic variables, and survival of patients with primary mediastinal diffuse large B cell lymphoma (PMBCL) in the rituximab era. The Surveillance, Epidemiology, and End Results (SEER) database was used to identify PMBCL patients diagnosed between 2000 and 2019. The Kaplan-Meier (K-M) technique and log-rank test were used to assess overall survival (OS) and disease-specific survival (DSS). The independent prognostic variables for OS and DSS were identified using univariate and multivariate Cox regression analysis. Nomograms were created to predict survival prospects according to identified prognostic indicators. Totally, 841 patients were enrolled with PMBCL. One-year, 5-year, and 10-year OS rates were 93.99%, 85.04%, and 81.76%, and the corresponding DSS rates were 95.27%, 87.37%, and 85.98%. The results of multivariate Cox regression analysis demonstrated that age, years of diagnosis, Ann arbor staging, and chemotherapy were independent prognostic factors for survival. Nomograms designed exclusively for PMBCL were created to forecast the likelihood of 1-year, 5-year, and 10-year OS and DSS, respectively. The Harrell concordance index (C-index) for the nomograms predictions of OS and DSS were 0.704 and 0.733, respectively, which showed the established model harboring powerful and accurate performance. The present study revealed that incidence of PMBCL has been consistently rising over the last 20 years. Simultaneously, survival rates have improved tremendously. Rituximab based immunochemotherapy has emerged as an effective treatment option, leading to enhanced OS and DSS outcomes. Furthermore, the nomograms specifically developed for PMBCL have demonstrated robustness and accuracy in forecasting OS and DSS rates at 1, 5, and 10 years. These predictive tools can be valuable for clinicians in accurately estimating prognosis and establishing personalized treatment plans and follow-up protocols.

Molecular Characterization of Primary Mediastinal Large B-Cell Lymphomas

Since the description of primary mediastinal large B-cell lymphoma (PMBL) as a distinct entity from diffuse large B-cell lymphomas (DLBCL), numerous studies have made it possible to improve their definition. Despite this, this differential diagnosis can be challenging in daily practice. However, in some centers, PMBL may be treated according to a particular regimen, distinct from those used in DLBCL, emphasizing the importance of accurate identification at diagnosis. This study aimed to describe the histological and molecular characteristics of PMBL to improve the accuracy of their diagnosis. Forty-nine cases of PMBL were retrospectively retrieved. The mean age at diagnosis was 39 years (21-83), with a sex ratio of 0.88. All cases presented a fibrous background with diffuse growth of intermediate to large cells with an eosinophil (26/49, 53%) or retracted cytoplasm (23/49, 47%). "Hodgkin-like" cells were observed in 65% of cases (32/49, 65%). The phenotype was: BCL6+ (47/49, 96%), MUM1+ (40/49, 82%), CD30+ (43/49, 88%), and CD23+ (37/49, 75%). Genomic DNAs were tested by next generation sequencing of 33 cases using a custom design panel. Pathogenic variants were found in all cases. The most frequent mutations were: SOCS1 (30/33, 91%), TNFAIP3 (18/33, 54.5%), ITPKB (17/33, 51.5%), GNA13 (16/33, 48.5%), CD58 (12/33, 36.4%), B2M (12/33; 36.4%), STAT6 (11/33, 33.3%) as well as ARID1A (10/33, 30.3%), XPO1 (9/33, 27.3%), CIITA (8/33, 24%), and NFKBIE (8/33, 24%). The present study describes a PMBL cohort on morphological, immunohistochemical, and molecular levels to provide pathologists with daily routine tools. These data also reinforce interest in an integrated histomolecular diagnosis to allow a precision diagnosis as early as possible.

PET/CT in Non-Hodgkin Lymphoma: An Update

Non-Hodgkin lymphomas represents a heterogeneous group of lymphoproliferative disorders characterized by different clinical courses, varying from indolent to highly aggressive. ¹⁸F-FDG-PET/CT is the current state-of-the-art diagnostic imaging, for the staging, restaging and evaluation of response to treatment in lymphomas with avidity for ¹⁸F-FDG, despite it is not routinely recommended for surveillance. PET-based response criteria (using five-point Deauville Score) are nowadays uniformly applied in FDG-avid lymphomas. In this review, a comprehensive overview of the role of ¹⁸F-FDG-PET in Non-Hodgkin lymphomas is provided, at each relevant point of patient management, particularly focusing on recent advances on diffuse large B-cell lymphoma and follicular lymphoma, with brief updates also on other histotypes (such as marginal zone, mantle cell, primary mediastinal- B cell lymphoma and T cell lymphoma). PET-derived semiquantitative factors useful for patient stratification and prognostication and emerging radiomics research are also presented.

Efficacy and safety of PD-1/PD-L1 immune checkpoint inhibitors in treating non-Hodgkin lymphoma: A systematic review and meta-analysis of clinical trials

BACKGROUND

Immunotherapy with programmed cell death protein-1 (PD-1)/programmed cell death ligand-1 (PD-L1) inhibitors has been widely used in the treatment of solid tumors and Hodgkin lymphoma, demonstrating powerful efficacy and good safety. However, there is no systematic review and meta-analysis to fully investigate the efficacy and safety of PD-1/PD-L1 inhibitors in treating non-Hodgkin lymphoma (NHL).

METHODS

We searched PubMed, EMBASE, The Cochrane Library, China National Knowledge Infrastructure, Wanfang database, and abstracts of conference proceedings of annual meetings up to January 23, 2022, to identify eligible clinical trials. To evaluate the efficacy of PD-1/PD-L1 inhibitors, objective response rate (ORR), complete response rate (CRR), 1-year overall survival rate, and 1-year progression-free survival rate were analyzed. For safety analysis, we calculated rates of any grade and grade ≥3 treatment-related adverse events.

RESULTS

Overall 22 studies and 1150 participants were enrolled in this meta-analysis. The pooled ORR, CRR, 1-year overall survival, and 1-year progression-free survival rates were 0.43 (95% confidence interval [CI], 0.33-0.54), 0.21 (95% CI, 0.13-0.31), 0.72 (95% CI, 0.58-0.89), and 0.42 (95% CI, 0.29-0.62), respectively. The ORR and CRR in the combination immunochemotherapy subgroup (0.65 and 0.41) were higher than those in the monotherapy (0.27 and 0.09) and combination chemotherapy (0.39 and 0.19) subgroups. This study was registered with PROSPERO (#CRD 42022316805).

CONCLUSION

Given that there were limited clinical trials and relatively few relevant studies, we conducted this meta-analysis to fully elucidate the efficacy and safety of PD-1/PD-L1 inhibitors in NHL. Our results suggested that PD-1/PD-L1 inhibitors improved outcomes of responses as well as survival rates in NHL patients with tolerable adverse events. More well-designed randomized clinical trials are still needed to further confirm our findings.

Pediatric Aggressive Mature B-Cell Lymphomas, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pediatric Aggressive Mature B-Cell Lymphomas include recommendations for the diagnosis and management of pediatric patients with primary mediastinal large B-cell lymphoma (PMBL) and sporadic variants of Burkitt lymphoma and diffuse large B-cell lymphoma. PMBL is now considered as a distinct entity arising from mature thymic B-cells accounting for 2% of mature B-cell lymphomas in children and adolescents. This discussion section includes the recommendations outlined in the NCCN Guidelines for the diagnosis and management of pediatric patients with PMBL.

Interim results of the PML-16, PML-19 protocols for primary mediastinal large B-cell lymphoma therapy

Introduction. Primary mediastinal lymphoma (PML) is an aggressive lymphoid tumor treatment success of which is determined by induction therapy. To date, none of the standard chemotherapy regimens (CT) have demonstrated an advantage in efficacy. Intensive therapy programs are associated with high toxicity.

Aim — to evaluate the efficacy and toxicity of two pilot prospective treatment protocols PML-16 and PML-19 as well as the possibility of using the analysis of freely circulating tumor DNA (ctDNA) to assess MRD in patients with PML.

Materials and methods. From January 2016 to January 2022, 34 previously untreated PML patients were included in the study; average age — 32; stage > I — in 60 %; extramediastinal lesions — in 14.7 %; bulky disease — in 73.5 % of patients. Positron emission tomography combined with computed tomography (PET-CT) was performed; ctDNA was determined to assess the completeness of remission.

Results. Eighteen patients received treatment according to the PML-16 protocol (6 courses of chemotherapy; 2 blocks of RmNHL-BFM-90 + 4 courses of R-EPOCH). After the end of therapy, all 18 patients achieved PET-negative remission. The next 16 patients received treatment according to the PML-19 protocol (4 courses of chemotherapy; 2 blocks of R-mNHL-BFM-90 + 2 courses of R-EPOCH) in combination with lenalidomide. After the end of therapy, 9 (56 %) patients achieved PET-negative remission; 7 (44 %) retained pathological activity (D4–5 points). After 3 and 6 months 15 (94 %) patients achieved normalization of metabolic activity. Considering the high frequency of false-positive results in patients with PML, a ctDNA study was performed to determine the depth of remission in 15 patients. After the end of therapy, all 15 patients had complete elimination of ctDNA. Of these, 5 (33 %) remained PET-positive at the end of treatment. During further observation, after 3–6 months, in 4 patients the level of metabolic activity decreased to physiological without the use of consolidating therapy. After the end of therapy, one patient suffered the new coronavirus infection, COVID-19. A month later, residual formation of SUVmax 14.2 remained in the mediastinum. The patient is currently under observation. With a median follow-up of 36 months (9 to 76 months) all 34 patients are in remission.

Conclusion. The effectiveness of PML-16 made it possible to abandon the consolidation therapy and refuted the idea of the need for 6 courses of CT. The combination of programs based on the application of the principle of high-dose shortpulse induction of remission (R-mNHL-BFM-90) in combination with the prolonged administration of medium doses (R-EPOCH) was crucial in achieving a successful result. The inclusion of lenalidomide in the “PML-19” program made it possible to achieve complete remission in 100 % of cases after 4 courses. The possibility of using DNA analysis to assess MRD in patients with PML was shown.

PD-1/PD-L1 Pathway: A Therapeutic Target in CD30+ Large Cell Lymphomas

The programmed death-ligands, PD-L1 and PD-L2, reside on tumor cells and can bind with programmed death-1 protein (PD-1) on T-cells, resulting in tumor immune escape. PD-1 ligands are highly expressed in some CD30+ large cell lymphomas, including classic Hodgkin lymphoma (CHL), primary mediastinal large B-cell lymphoma (PMBL), Epstein–Barr virus (EBV)-positive diffuse large B-cell lymphoma (EBV+ DLBCL), and anaplastic large cell lymphoma (ALCL). The genetic alteration of the chromosome 9p24.1 locus, the location of PD-L1, PD-L2, and JAK2 are the main mechanisms leading to PD-L1 and PD-L2 overexpression and are frequently observed in these CD30+ large cell lymphomas. The JAK/STAT pathway is also commonly constitutively activated in these lymphomas, further contributing to the upregulated expression of PD-L1 and PD-L2. Other mechanisms underlying the overexpression of PD-L1 and PD-L2 in some cases include EBV infection and the activation of the mitogen-activated protein kinase (MAPK) pathway. These cellular and molecular mechanisms provide a scientific rationale for PD-1/PD-L1 blockade in treating patients with relapsed/refractory (R/R) disease and, possibly, in newly diagnosed patients. Given the high efficacy of PD-1 inhibitors in patients with R/R CHL and PMBL, these agents have become a standard treatment in these patient subgroups. Preliminary studies of PD-1 inhibitors in patients with R/R EBV+ DLBCL and R/R ALCL have also shown promising results. Future directions for these patients will likely include PD-1/PD-L1 blockade in combination with other therapeutic agents, such as brentuximab or traditional chemotherapy regimens.

Thymolipoma - the frontier between hamartoma and neoplasia?

Thymolipoma is an uncommon benign thymus lesion, with a partially deciphered etiopathogeny, being most frequently diagnosed in young patients, regardless of gender. Incidentally diagnosed in asymptomatic patients, larger thymolipomas lead to symptoms related to neighboring mediastinal structures compression, with an intensity which is correlated with the mass size. Our review presents the main epidemiological, pathogenic, clinicopathological and morphological characteristics of this rare pathology. Sometimes, thymolipomas may be associated with paraneoplastic syndromes, which are alleviated by the mass complete surgical resection. Imagistics may orientate the diagnosis, which is certified by the microscopic examination of the resection specimens. Extensive thymectomy remains the current therapeutic option and new tools have been developed to increase the accuracy of the surgical procedure to avoid incidental lesions of the important elements of the anterior mediastinum. Although rare, thymolipomas should be considered in the differential diagnosis of mediastinal masses and of paraneoplastic syndromes.