IGH::NSD2 Fusion Gene Transcript as Measurable Residual Disease Marker in Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological malignancy. Approximately 15% of MM patients are affected by the t(4;14) translocation resulting in the IGH::NSD2 fusion transcript. Breakage occurs in three major breakpoint regions within the NSD2 gene (MB4-1, MB4-2, and MB4-3), where MB4-1 leads to the production of full-length protein, while truncated proteins are expressed in the other two cases. Measurable residual disease (MRD) has been conclusively established as a crucial prognostic factor in MM. The IGH::NSD2 fusion transcript can serve as a sensitive MRD marker. Using bone marrow (BM) and peripheral blood (PB) samples from 111 patients, we developed a highly sensitive quantitative real-time PCR (qPCR) and digital PCR (dPCR) system capable of detecting fusion mRNAs with a sensitivity of up to 1:100,000. PB samples exhibited sensitivity three orders of magnitude lower compared to BM samples. Patients with an MB4-2 breakpoint demonstrated significantly reduced overall survival (p = 0.003). Our novel method offers a simple and sensitive means for detecting MRD in a substantial proportion of MM patients. Monitoring may be carried out even from PB samples. The literature lacks consensus regarding survival outcomes among patients with different NSD2 breakpoints. Our data align with previous findings indicating that patients with the MB4-2 breakpoint type tend to exhibit unfavorable overall survival.

The Role of t(11;14) in Tailoring Treatment Decisions in Multiple Myeloma

Multiple myeloma (MM) represents a hematological neoplasia with an uncontrolled proliferation of malignant plasma cells and complex cytogenetic abnormalities. t(11;14) has emerged as a crucial genetic aberration and is one of the most common primary translocations in MM. Patients harboring t(11;14) represent a distinctive subgroup with a clinical profile that differs from t(11;14)-negative MM risk categories. One of the key features linked with t(11;14) is the BCL2 dependency, indicating vulnerability to BCL2 inhibition. BCL2 inhibitors, such as venetoclax, demonstrated impressive efficacy alone or in combination with other anti-myeloma drugs in patients with RRMM accompanied by t(11;14) and BCL2 overexpression. Therefore, t(11;14) plays a key role in both risk stratification and informed decision making towards a tailored therapy. In this review, we highlight the biology of t(11;14) in MM cells, summarize the current evolving role of t(11;14) in the era of novel agents and novel targeted therapies, illuminate current efficacy and safety data of BCL2-based treatment options and explore the future prospects of individualized precision medicine for this special subgroup of patients with MM.

CD5-Negative Primary Mantle Cell Lymphoma Presenting with a Bilateral Conjunctival Mass: A Potential Diagnostic Pitfall

Mantle cell lymphoma is a B-cell malignancy, which, in its classic form, usually involves lymph nodes and extranodal sites, and, among the extranodal sites, the gastrointestinal tract and the Waldeyer's ring are most prevalent. MCL is rarely reported in the ocular adnexa, a site more frequently affected by extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue, which is a form of low-grade malignancy. The diagnosis of MCL presenting in the ocular adnexa requires special attention as its rarity in this location combined with the not uncommon CD5 negativity of the disease when occurring in the ocular adnexa, may lead the pathologist to overlook the diagnosis and misinterpret MCL as marginal zone B cell lymphoma, which has a totally different behavior. Herein, we present a case of primary bilateral conjunctival CD5-negative MCL in a patient having no other sites affected by lymphoma and we discuss possible diagnostic pitfalls.

Transcriptomic Analysis in Multiple Myeloma and Primary Plasma Cell Leukemia with t(11;14) Reveals Different Expression Patterns with Biological Implications in Venetoclax Sensitivity

Simple Summary

The growing interest in BCL2 inhibitors for the treatment of multiple myeloma (MM) has led to the need for biomarkers that are able to predict patient’s sensitivity to the drug. The presence of the chromosomal translocation t(11;14) in MM is mainly associated with sensitivity to venetoclax and good prognosis. The incidence of t(11;14) largely increases in primary Plasma Cell Leukemia (pPCL) in association with an unfavorable outcome. Currently, data concerning pPCL sensitivity to venetoclax are virtually absent. In this context, we investigated the transcriptome of MM and pPCL with t(11;14), evidencing that the two clinical entities are likely responsive to venetoclax based on different molecular programs, thus prompting further studies to elucidate better novel potential predictive biomarkers.

Abstract

Mechanisms underlying the pathophysiology of primary Plasma Cell Leukemia (pPCL) and intramedullary multiple myeloma (MM) need to be further elucidated, being potentially relevant for improving therapeutic approaches. In such a context, the MM and pPCL subgroups characterized by t(11;14) deserve a focused investigation, as the presence of the translocation is mainly associated with sensitivity to venetoclax. Herein, we investigated a proprietary cohort of MM and pPCL patients, focusing on the transcriptional signature of samples carrying t(11;14), whose incidence increases in pPCL in association with an unfavorable outcome. In addition, we evaluated the expression levels of the BCL2-gene family members and of a panel of B-cell genes recently reported to be associated with sensitivity to venetoclax in MM. Moreover, transcriptional analysis of lncRNAs in the two clinical settings led to the identification of several differentially expressed transcripts, among which the SNGH6 deregulated lncRNA might be relevant in the pathogenesis and prognosis of pPCL with t(11;14). Overall, our data suggest that MMs and pPCLs with t(11;14) might be responsive to venetoclax based on different molecular programs, prompting further studies to elucidate better novel potential predictive biomarkers.