Prevalence and Prognostication of CD5+ Mature T-Cell Lymphomas.

Background: T-cell lymphomas (TCLs) are a group of heterogenous cancers with poor rates and duration of response. There remains a great challenge in risk stratification of these cancers. Cluster of differentiation (CD) 5 has shown prognostic implication in many subtypes of B-cell lymphoma; however, its role in TCLs is not known. Methods: We performed a single-institution retrospective analysis of newly diagnosed patients with TCL. CD5 positivity was determined based on positive results via immunohistochemistry and/or flow cytometry. We used univariate and multivariable analysis of biological factors to assess their association with survival outcomes. Results: A total of 194 patients with TCL spanning 14 subtypes were identified. CD5 positivity was noted in 63% of patients, with the highest proportion of CD5 expression in TFH TCL (93.9%), PTCL-NOS (82.9%), and ATLL (77.8%) (p = 0.00004). Older age at diagnosis (p = 0.001), stage III or IV disease (p = 0.05), and bone marrow involvement (p = 0.003) were also associated with CD5 expression. Complete response rates were numerically lower in patients with CD5+ TCL across all subtypes. OS/PFS was not statistically associated with CD5 status in the overall cohort; however there was significantly decreased OS in CD5+ TFH TCL (p = 0.04) and CD5+ ATLL (p = 0.04) patients. Conclusions: This study represents the first to examine CD5 expression as a prognostic biomarker for outcomes in TCL. The frequent expression of CD5 in the most common nodal TCL in the Western world underpins its potential as an attractive target for cellular therapies. Confirmation of these findings in a larger cohort and investigation of potential pathophysiological mechanisms explaining our observations are planned.

Evaluation of Ki-67 expression and large cell content as prognostic markers in MZL: a multicenter cohort study.

Marginal zone lymphoma (MZL) can have varied presentations and pathologic features, including high Ki-67 expression ( > 20%) as well as increased numbers of large B cells (LC). However, there are limited data available demonstrating the prognostic significance of these variables in patients with MZL. In this multi-institutional retrospective cohort study of patients with MZL treated at 10 centers, we evaluated the association between the presence of Ki-67 expression and increased LCs on survival and risk of histologic transformation (HT). A total of 785 patients were included (60% with extranodal MZL, 20% with nodal MZL, and 20% with splenic MZL). Among the 440 patients with Ki-67 staining, 22% had high Ki-67 (Ki-67 >20%). The median progression-free survival (PFS) for patients with high Ki-67 was 5.4 years compared to 7.0 years for patients with low Ki-67 (HR = 1.45, 95%CI = 1.03-2.05). Ki-67 > 20% strongly correlated with high LDH level. The risk of HT was higher in patients with increased Ki-67 than those without (5-year risk, 9.8% vs 3.87%, p = 0.01). Twelve percent of patients had LC reported on biopsy with 6% having >10% LC. The presence of LC was associated with high Ki-67 (p < 0.001), but not associated with shorter PFS or overall survival (OS). The cumulative risk for HT was higher in patients with LC compared to those without LC (5-year risk, 9.4% vs 2.9%, p = 0.04). Receipt of anthracycline-based therapy did not impact PFS or OS in either group. Ki-67 staining >20% was a prognostic factor for worse survival and strongly correlated with elevated LDH. Novel therapies should be investigated for their potential ability to overcome the high-risk features in MZL. Our data reinforce the importance of obtaining biopsies at relapse or progression, particularly in patients with baseline high Ki-67 and increased LCs, given their increased risk for HT.

2024 Update: Advances in the risk stratification and management of large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with varying clinical outcomes. Our understanding of its molecular makeup continues to improve risk stratification, and artificial-intelligence and ctDNA-based analyses have the potential to enhance risk assessment and disease monitoring. R-CHOP and Pola-R-CHP are used in the frontline setting; chimeric antigen receptor therapy (CART) is now the new standard-of-care for most with primary refractory disease; both CART and autologous stem cell transplantation are utilized in the relapsed and refractory setting. In this review, we summarize the classification and management of DLBCL with an emphasis on recent advances in the field.

Impact of detectable monoclonal protein at diagnosis on outcomes in marginal zone lymphoma: a multicenter cohort study.

Given the paucity of data surrounding the prognostic relevance of monoclonal paraprotein (M-protein) in marginal zone lymphoma (MZL), we sought to evaluate the impact of detecting M-protein at diagnosis on outcomes in patients with MZL in a large retrospective cohort. The study included 547 patients receiving first-line therapy for MZL. M-protein was detectable at diagnosis in 173 (32%) patients. There was no significant difference in the time from diagnosis to initiation of any therapy (systemic and local) between the M-protein and no M-protein groups. Patients with M-protein at diagnosis had significantly inferior progression-free survival (PFS) compared with those without M-protein at diagnosis. After adjusting for factors associated with inferior PFS in univariate models, presence of M-protein remained significantly associated with inferior PFS (hazard ratio, 1.74; 95% confidence interval, 1.20-2.54; P = .004). We observed no significant difference in the PFS based on the type or quantity of M-protein at diagnosis. There were differential outcomes in PFS based on the first-line therapy in patients with M-protein at diagnosis, in that, those receiving immunochemotherapy had better outcomes compared with those receiving rituximab monotherapy. The cumulative incidence of relapse in stage 1 disease among the recipients of local therapy was higher in the presence of M-protein; however, this did not reach statistical significance. We found that M-protein at diagnosis was associated with a higher risk of histologic transformation. Because the PFS difference related to presence of M-protein was not observed in patients receiving bendamustine and rituximab, immunochemotherapy may be a preferred approach over rituximab monotherapy in this group and needs to be explored further.

Impact of early relapse within 24 months after first-line systemic therapy (POD24) on outcomes in patients with marginal zone lymphoma: A US multisite study.

Progression of disease within 24 months (POD24) from diagnosis in marginal zone lymphoma (MZL) was shown to portend poor outcomes in prior studies. However, many patients with MZL do not require immediate therapy, and the time from diagnosis-to-treatment interval can be highly variable with no universal criteria to initiate systemic therapy. Hence, we sought to evaluate the prognostic relevance of early relapse or progression within 24 months from systemic therapy initiation in a large US cohort. The primary objective was to evaluate the overall survival (OS) in the two groups. The secondary objective included the evaluation of factors predictive of POD24 and the assessment of cumulative incidence of histologic transformation (HT) in POD24 versus non-POD24 groups. The study included 524 patients with 143 (27%) in POD24 and 381 (73%) in non-POD24 groups. Patients with POD24 had inferior OS compared to those without POD24, regardless of the type of systemic therapy received (rituximab monotherapy or immunochemotherapy) at diagnosis. After adjusting for factors associated with inferior OS in the univariate Cox model, POD24 remained associated with significantly inferior OS (HR = 2.50, 95% CI = 1.53-4.09, p = 0.0003) in multivariable analysis. The presence of monoclonal protein at diagnosis and those who received first-line rituximab monotherapy had higher odds of POD24 on logistic regression analysis. Patients with POD24 had a significantly higher risk for HT compared to those without POD24. POD24 in MZL might be associated with adverse biology and could be used as an additional information point in clinical trials and investigated as a marker for worse prognosis.

A Novel Paradigm Between Leukocytosis, G-CSF Secretion, Neutrophil-to-Lymphocyte Ratio, Myeloid-Derived Suppressor Cells, and Prognosis in Non-small Cell Lung Cancer.

Leukocytosis is a common feature of malignancies. While controversial, there appears to be an association between the degree of tumor-related leukocytosis and prognosis. In this paper, we provide evidence supporting an untapped clinical paradigm linking G-CSF secretion to the induction of leukocytosis and expansion of myeloid-derived suppressor cells, providing an explanation for the association between leukocytosis, elevated neutrophil-to-lymphocyte ratios and prognosis in non-small cell lung cancer. Clinically validating this mechanism may identify MDSCs and G-CSF as dynamic markers of early disease progression and therapeutic response, and shed light onto novel therapeutic avenues for the treatment of patients with non-small cell lung cancer.

Cutaneous Ewing Sarcoma and Ewing Sarcoma of the Bone: Distinct Diseases.

Ewing sarcoma is an aggressive mesenchymal malignancy. It is the second most common bone tumor among children and adolescents and less commonly presents as a soft tissue or primary skin lesion. Cutaneous Ewing sarcoma has only been reported in case reports and case series. In this article, we describe a 12-year-old Hispanic female cured of localized, cutaneous Ewing sarcoma (pT1aN0M0) at the 40-month follow-up following surgical resection and adjuvant chemotherapy according to the COG AEWS1031 protocol for Ewing sarcoma of the bone. To our knowledge, this is the first article to provide a potential biological explanation for the differences in the prognosis of Ewing sarcoma of the bone, soft tissue, and skin.

Do preclinical studies suggest that CD99 is a potential therapeutic target in acute myeloid leukemia and the myelodysplastic syndromes?

INTRODUCTION: Acute myeloid leukemia (AML) and the myelodysplastic syndromes (MDS) are clonal hematopoietic neoplasms that arise from leukemia stem cells (LSCs) and hematopoietic stem cells (HSCs), respectively. Standard chemotherapy can efficiently eliminate the bulk of neoplastic cells, however, LSCs and MDS HSCs are relatively resistant to these therapies and can reinitiate and maintain disease. CD99 is a 32-kDa transmembrane polypeptide that is highly expressed on disease stem cells in the vast majority of AML and MDS. Areas covered: In this editorial, we focus on the current literature surrounding the identification of CD99 as a marker of MDS and AML stem cells and preclinical studies revealing the therapeutic efficacy of targeting CD99 in these diseases. Expert opinion/commentary: Cytotoxic CD99 monoclonal antibodies represent promising stem cell-directed therapies that have the potential to markedly improve clinical outcomes for these difficult-to-treat hematologic malignancies.

CD99 is a therapeutic target on disease stem cells in myeloid malignancies.

Acute myeloid leukemia (AML) and the myelodysplastic syndromes (MDS) are initiated and sustained by self-renewing malignant stem cells; thus, eradication of AML and MDS stem cells is required for cure. We identified CD99 as a cell surface protein frequently overexpressed on AML and MDS stem cells. Expression of CD99 allows for prospective separation of leukemic stem cells (LSCs) from functionally normal hematopoietic stem cells in AML, and high CD99 expression on AML blasts enriches for functional LSCs as demonstrated by limiting dilution xenotransplant studies. Monoclonal antibodies (mAbs) targeting CD99 induce the death of AML and MDS cells in a SARC family kinase-dependent manner in the absence of immune effector cells or complement, and anti-CD99 mAbs exhibit antileukemic activity in AML xenografts. These data establish CD99 as a marker of AML and MDS stem cells, as well as a promising therapeutic target in these disorders.

Pathogenic microRNA's in myeloid malignancies.

Recent studies have significantly improved our understanding of the role microRNAs (miRNAs) play in regulating normal hematopoiesis. miRNAs are critical for maintaining hematopoietic stem cell function and the development of mature progeny. Thus, perhaps it is not surprising that miRNAs serve as oncogenes and tumor suppressors in hematologic malignancies arising from hematopoietic stem and progenitor cells, such as the myeloid disorders. A number of studies have extensively documented the widespread dysregulation of miRNA expression in human acute myeloid leukemia (AML), inspiring numerous explorations of the functional role of miRNAs in myeloid leukemogenesis. While these investigations have confirmed that a large number of miRNAs exhibit altered expression in AML, only a small fraction has been confirmed as functional mediators of AML development or maintenance. Herein, we summarize the miRNAs for which strong experimental evidence supports their functional roles in AML pathogenesis. We also discuss the implications of these studies on the development of miRNA-directed therapies in AML.

Survivorship in adolescents and young adults.

In the USA, approximately 26,000 adolescents and young adults (AYAs) aged 15-29 years are diagnosed with cancer every year. The cure rate among this population exceeds 80%, resulting in a growing number of AYA cancer survivors. AYA cancer survivors suffer from a wide range of long-term treatment-related toxicities that adversely affect quality of life and increase the risk of premature death. Therefore, it is important to recognize the unique medical needs of the AYA cancer survivors and develop a cost-effective and systemic approach to screen and prevent cancer treatment-related sequelae and the adverse health outcomes.

A high-resolution gene expression map of the Arabidopsis shoot meristem stem cell niche.

The shoot apical meristem (SAM) acts as a reservoir for stem cells. The central zone (CZ) harbors stem cells. The stem cell progenitors differentiate in the adjacent peripheral zone and in the rib meristem located just beneath the CZ. The SAM is further divided into distinct clonal layers: the L1 epidermal, L2 sub-epidermal and L3 layers. Collectively, SAMs are complex structures that consist of cells of different clonal origins that are organized into functional domains. By employing fluorescence-activated cell sorting, we have generated gene expression profiles of ten cell populations that belong to different clonal layers as well as domains along the central and peripheral axis. Our work reveals that cells in distinct clonal layers exhibit greater diversity in gene expression and greater transcriptional complexity than clonally related cell types in the central and peripheral axis. Assessment of molecular functions and biological processes reveals that epidermal cells express genes involved in pathogen defense: the L2 layer cells express genes involved in DNA repair pathways and telomere maintenance, and the L3 layers express transcripts involved in ion balance and salt tolerance besides photosynthesis. Strikingly, the stem cell-enriched transcriptome comprises very few hormone-responsive transcripts. In addition to providing insights into the expression profiles of hundreds of transcripts, the data presented here will act as a resource for reverse genetic analysis and will be useful in deciphering molecular pathways involved in cell type specification and their functions.

WUSCHEL mediates stem cell homeostasis by regulating stem cell number and patterns of cell division and differentiation of stem cell progenitors.

Plant stem cell populations, unlike their animal counterparts, do not use cell migration and oriented cell divisions to maintain their size, and therefore require a precise coordination between self-renewing divisions of stem cells, and rates of cell division and differentiation among stem cell progenitors. Shoot apical meristems (SAMs) of higher plants harbor a set of stem cells within the central zone (CZ) that divide infrequently. Stem cell daughters that are displaced towards the surrounding peripheral zone (PZ) divide at a faster rate and enter into differentiation at specific locations to form leaves or flowers. The relative ratios of cells in the CZ and the PZ are maintained, despite a constant displacement of cells from the CZ into the PZ, and subsequent allocation of cells within the PZ to form organ primordia. The mechanisms that mediate this homeostatic balance are not well understood. A homeodomain transcription factor WUSCHEL, expressed in the rib meristem (RM), located beneath the CZ, has been shown to provide nonautonomous cues for stem cell specification. By employing transient spatial manipulation and live imaging, we show that an elevated level of WUS not only induces expansion of the CZ, but also results in increased cell division rates in cells of the PZ; conversely, decreases in WUS level lead to a smaller CZ and are associated with a reduction in cell division rate. Moreover, low levels of WUS lead to enlarged organ primordia, by elevating the responsiveness of the PZ cells to the plant hormone auxin. This reveals a function of WUS in mediating the balance between differentiating and non-differentiating cells of the PZ. Regulation of stem cell numbers, growth and differentiation patterns by a single transcription factor forms a interconnected and self-correcting feedback loop to provide robustness to stem cell homeostasis in a dynamic cellular environment.