Molecular Heterogeneity in Localized Diffuse Large B-Cell Lymphoma

Practical microenvironment classification in diffuse large B cell lymphoma using digital pathology

Diffuse large B cell lymphoma (DLBCL) is a heterogeneous B cell neoplasm with variable clinical outcomes influenced by both tumor-derived and lymphoma microenvironment (LME) alterations. A recent transcriptomic study identifies four DLBCL subtypes based on LME characteristics: germinal center (GC)-like, mesenchymal (MS), inflammatory (IN), and depleted (DP). However, integrating this classification into clinical practice remains challenging. Here, we utilize deconvolution methods to assess microenvironment component abundance, establishing an LME classification of DLBCL using immunohistochemistry markers and digital pathology based on CD3, CD8, CD68, PD-L1, and collagen. This staining-based algorithm demonstrates over 80% concordance with transcriptome-based classification. Single-cell sequencing confirms that the immune microenvironments distinguished by this algorithm align with transcriptomic profiles. Significant disparities in overall and progression-free survival are observed among LME subtypes following rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) or R-CHOP with targeted agents (R-CHOP-X) immunochemotherapy. LME subtypes differed from distinct immune escape mechanisms, highlighting specific immunotherapeutic targets and supporting application of this classification in future precision medicine trials.

Progress in deciphering the role of p53 in diffuse large B-cell lymphoma: mechanisms and therapeutic targets

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype, accounting for 30%-40% of non-Hodgkin lymphoma in adults. The mechanisms underlying DLBCL occurrence are extremely complex, and involve the B-cell receptor (BCR) and Toll-like receptor (TLR) signaling pathways, as well as genetic abnormalities and other factors. With the development of high-throughput sequencing, an increasing number of abnormal genes have been identified in DLBCL. Among them, the tumor protein p53 (TP53/p53) gene is important in DLBCL occurrence. Patients with DLBCL carrying TP53 gene abnormalities generally have poor prognosis and studies of p53 have potential to provide a better basis for their treatment. Normally, p53 is maintained at low levels through its interaction with murine double minute 2 (MDM2), and prevents tumorigenesis by mediating cell cycle arrest, apoptosis, and repair of damaged cells, among other processes. Therefore, the prognosis of patients with DLBCL harboring TP53 gene abnormalities (mutations, deletions, etc.) is poor, and targeting p53 for tumor therapy has become a research hotspot, following developments in molecular biology technologies. Current treatments targeting p53 mainly act by restoring the function or promoting degradation of mutant p53, and enhancing wild-type p53 protein stability and activity. Based on the current status of p53 research, exploration of existing therapeutic methods to improve the prognosis of patients with DLBCL with TP53 abnormalities is warranted.

Biological signatures of the International Prognostic Index in diffuse large B-cell lymphoma

ABSTRACT

Diffuse large B-cell lymphoma (DLBCL) is a highly aggressive subtype of lymphoma with clinical and biological heterogeneity. The International Prognostic Index (IPI) shows great prognostic capability in the era of rituximab, but the biological signatures of IPI remain to be discovered. In this study, we analyzed the clinical data in a large cohort of 2592 patients with newly diagnosed DLBCL. Among them, 1233 underwent DNA sequencing for oncogenic mutations, and 487 patients underwent RNA sequencing for lymphoma microenvironment (LME) alterations. Based on IPI scores, patients were categorized into 4 distinct groups, with 5-year overall survival of 41.6%, 55.3%, 71.7%, and 89.7%, respectively. MCD-like subtype was associated with age of >60 years, multiple extranodal involvement, elevated serum lactate dehydrogenase (LDH), and IPI scores ranging from 2 to 5, whereas ST2-like subtype showed an opposite trend. Patients with EZB-like MYC+ and TP53Mut subtypes exhibited poor clinical outcome independent of the IPI; integrating TP53Mut into IPI could better distinguish patients with dismal survival. The EZB-like MYC-, BN2-like, N1-like, and MCD-like subtypes had inferior prognosis in patients with IPI scores of ≥2, indicating necessity for enhanced treatment. Regarding LME categories, the germinal center-like LME was more prevalent in patients with normal LDH and IPI scores of 0 to 1. The mesenchymal LME served as an independent protective factor, whereas the germinal center-like, inflammatory, and depleted LME categories correlated with inferior prognosis for IPI scores of 2 to 5. In summary, our work explored the biological signatures of IPI, thus providing useful rationale for future optimization of the IPI-based treatment strategies with multi-omics information in DLBCL.

Clinical Features and Outcomes of Primary Breast Diffuse Large B-Cell Lymphoma: A Matched-Pair Study

Background

The influence of the breast as the primary site on the outcome of diffuse large B-cell lymphoma (DLBCL) and further changes in therapeutic strategies remain unclear. We aimed to compare the outcomes between primary breast and non-breast DLBCL and analyze the genetic profiles of some of the study cohorts using next-generation sequencing.

Methods

This matched-pair study reviewed the medical records of 19 patients with stage I and II primary breast DLBCL diagnosed between January 2005 and December 2021 on the basis of the Wiseman and Liao criteria, and we used 1:4 propensity score matching to identify patients with non-breast DLBCL as the control group. The overall response rate, progression-free survival (PFS), and overall survival (OS) were the outcome measures.

Results

Patients with primary breast and non-breast DLBCL had a 5-year PFS of 72.6% and 86.9%, respectively (P = .206). These 2 groups also had comparable 5-year OS (86.9% vs 87.8%; P = .772). The breast as the primary site was not associated with inferior PFS (hazard ratio [HR]: 2.14; 95% CI: 0.66-6.96; P = .206) and OS (HR: 1.26; 95% CI: 0.27-5.93; P = .772).

Conclusion

Patients with primary breast DLBCL and those with non-breast DLBCL had comparable PFS and OS under rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) or R-CHOP-like regimens. Further investigations of the mutation profile, its clinical impact, potential central nervous system relapse, and prognosis of primary breast DLBCL are required.

Genetic subtype-guided immunochemotherapy in diffuse large B cell lymphoma: The randomized GUIDANCE-01 trial

We report the results of GUIDANCE-01 (NCT04025593), a randomized, phase II trial of R-CHOP alone or combined with targeted agents (R-CHOP-X) guided by genetic subtyping of newly diagnosed, intermediate-risk, or high-risk diffuse large B cell lymphoma (DLBCL). A total of 128 patients were randomized 1:1 to receive R-CHOP-X or R-CHOP. The study achieved the primary endpoint, showing significantly higher complete response rate with R-CHOP-X than R-CHOP (88% vs. 66%, p = 0.003), with overall response rate of 92% vs. 73% (p = 0.005). Two-year progression-free survival rates were 88% vs. 63% (p < 0.001), and 2-year overall survival rates were 94% vs. 77% (p = 0.001). Meanwhile, post hoc RNA-sequencing validated our simplified genetic subtyping algorithm and previously established lymphoma microenvironment subtypes. Our findings highlight the efficacy and safety of R-CHOP-X, a mechanism-based tailored therapy, which dually targeted genetic and microenvironmental alterations in patients with newly diagnosed DLBCL.

Clinicopathological and molecular features of indolent natural killer-cell lymphoproliferative disorder of the gastrointestinal tract

AIMS

Indolent natural killer (NK) cell lymphoproliferative disorder of the gastrointestinal (GI) tract (iNKLPD) is a rare, recently recognised neoplasm. Most of the reported tumours are confined to the GI tract, while a small subset of the tumours harbour JAK3 mutations. We collected four cases of iNKLPD with the goal of adding additional information to the current knowledge of this disease regarding the clinicopathological, immunohistochemical and molecular features.

METHODS AND RESULTS

Similar features including medium- to large-sized lymphoid cells with variable amounts of pale or slightly eosinophilic cytoplasm, and no evidence of EBER, TCR rearrangement were found in four cases. JAK3 K563_C565del mutation was found in one of three cases that were subjected to targeted next-generation sequencing. Unique findings of our study include one iNKLPD encountered for the first time in nasopharynx, where lesions could be inadvertently diagnosed as extranodal NK/T cell lymphoma, and one iNKLPD located in the gallbladder extended deeply into muscular and adventitial layers. Exceptional CD8-positive expression was observed in one iNKLPD. In addition, positive staining of phospho-STAT5, phospho-STAT3 and phospho-p38 were found in our cases. None of the four patients received therapy for lymphoma, but all had a benign clinical outcome during a follow-up time of 20-99 months.

CONCLUSIONS

We present four iNKLPDs with clinical, immunohistochemical and molecular features similar to the reported cases, as well as some unusual characters, which expand our knowledge on this disease, and further support the neoplastic nature of iNKLPDs.

Case report: Successful management of a refractory double-expressor diffuse large B-cell lymphoma patient under the guidance of in vitro high-throughput drug sensitivity test

Introduction

Double-expressor diffuse large B-cell lymphoma (DEL), harboring double expression of MYC and BCL2, has an inferior prognosis following standard first-line therapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). We initiated a clinical trial to treat newly diagnosed DEL with R-CHOP plus Bruton's tyrosine kinase (BTK) inhibitor (BTKi) zanubrutinib (ZR-CHOP) and achieved a high complete response (CR) rate while four patients progressed during therapy, one of them carrying ATM and CD58 mutations. We applied an in vitro high-throughput drug sensitivity test for the prediction of clinical responses to different drugs in this patient.

Case presentation

We report a 30-year-old female patient diagnosed with stage III (DEL), with ATM and CD58 mutations. The patient achieved partial response (PR) after two cycles of ZR-CHOP and remained PR after four cycles of ZR-CHOP, while the disease progressed after six cycles of ZR-CHOP. High-throughput drug screening using a panel of 117 compounds identified a range of therapies with efficacy for this patient. The primary tumor cells showed moderate sensitivity to bortezomib, thalidomide, and gemcitabine as a single agent and bortezomib, thalidomide, and dexamethasone (VTD) as a combined regimen. The patient was treated with two cycles of VTD regimen (bortezomib 1.3 mg/m², d1, 4, 8, 11; thalidomide 100 mg, d1-21; dexamethasone 20 mg, d1, 2, 4, 5, 8, 9) and achieved PR with only a small lesion left. Another two cycles of VTD plus gemcitabine were then administered, and the patient achieved CR. Stem cells were mobilized, and autologous hematopoietic stem cell transplantation was carried out afterward. The patient remained CR for more than 3 months after transplantation.

Conclusion

In this article, we present a first-line chemoresistant DEL patient with ATM and CD58 mutations who was treated successfully with VTD plus gemcitabine under the guidance of in vitro high-throughput drug sensitivity test.

Targeted sequencing reveals the relationship between mutations and patients' clinical indicators, blood cell counts and early progression in diffuse large-B cell lymphoma

In the current study, we assessed the relationship between mutations and the blood cell counts and early progression of patients with diffuse large-B cell lymphoma (DLBCL). A total of 109 patients with newly diagnosed DLBCL were included in this study. UBE2A mutation was only found in patients with bone marrow involvement. The mutations of ZNF608, SF3B1, DTX1, and NCOR2 were related to blood cell counts. NCOR2 mutations were only detected in patients of the noncomplete response group (PR + SD + PD). In addition, the mutations of ATM, BTG2, TBL1XR1, and TP53 were linked to lower PFS/OS rate, while SGK1, SCOS1, and NFKBIE were related to higher PFS/OS rate. Importantly, we identified that Ann Arbor stage (III-IV), B symptoms, absolute lymphocyte count (ALC) abnormity, and MTOR mutation were the four independent influencing factors of the 12-month progression of DLBCL patients. Overall, this study revealed that mutations were associated with the early progression of DLBCL.

Oncogenic Mutations and Tumor Microenvironment Alterations of Older Patients With Diffuse Large B-Cell Lymphoma

The incidence of diffuse large B-cell lymphoma (DLBCL) increases by age and older DLBCL are commonly related to poor prognosis. However, the clinical and biological features of older DLBCL patients remain to be determined. A total of 2,445 patients with newly diagnosed DLBCL were enrolled for clinical data analysis according to age at diagnosis, with tumor samples of 1,150 patients assessed by DNA sequencing and 385 patients by RNA sequencing. Older DLBCL presented advanced disease stage, elevated serum lactate dehydrogenase, poor performance status, multiple extranodal involvement, high percentage of double expressor subtype, and adverse clinical outcome. According to molecular features, age was positively correlated with the oncogenic mutations of PIM1, MYD88, BTG2, CD79B, TET2, BTG1, CREBBP, TBL1XR1, and with the MYD88-like genetic subtype. These oncogenic mutations were involved in B-cell receptor/NF-κB signaling, B-cell differentiation, and histone acetylation based on biological functions. Older DLBCL also manifested reduction in CD4⁺ naïve T and CD8⁺ naïve T cells, and also increased recruitment of exhausted T cells and macrophages, leading to immunosuppressive tumor microenvironment. Our work thus contributes to the understanding of aging-related oncogenic mutations and tumor microenvironment alterations in lymphoma progression, and may provide new insights to mechanism-based targeted therapy in DLBCL.