The Lymphoma Epidemiology of Outcomes cohort study: Design, baseline characteristics, and early outcomes.

To address the current and long-term unmet health needs of the growing population of non-Hodgkin lymphoma (NHL) patients, we established the Lymphoma Epidemiology of Outcomes (LEO) cohort study (NCT02736357; https://leocohort.org/). A total of 7735 newly diagnosed patients aged 18 years and older with NHL were prospectively enrolled from 7/1/2015 to 5/31/2020 at 8 academic centers in the United States. The median age at diagnosis was 62 years (range, 18-99). Participants came from 49 US states and included 538 Black/African-Americans (AA), 822 Hispanics (regardless of race), 3386 women, 716 age <40 years, and 1513 rural residents. At study baseline, we abstracted clinical, pathology, and treatment data; banked serum/plasma (N = 5883, 76.0%) and germline DNA (N = 5465, 70.7%); constructed tissue microarrays for four major NHL subtypes (N = 1189); and collected quality of life (N = 5281, 68.3%) and epidemiologic risk factor (N = 4489, 58.0%) data. Through August 2022, there were 1492 deaths. Compared to population-based SEER data (2015-2019), LEO participants had a similar distribution of gender, AA race, Hispanic ethnicity, and NHL subtype, while LEO was underrepresented for patients who were Asian and aged 80 years and above. Observed overall survival rates for LEO at 1 and 2 years were similar to population-based SEER rates for indolent B-cell (follicular and marginal zone) and T-cell lymphomas, but were 10%-15% higher than SEER rates for aggressive B-cell subtypes (diffuse large B-cell and mantle cell). The LEO cohort is a robust and comprehensive national resource to address the role of clinical, tumor, host genetic, epidemiologic, and other biologic factors in NHL prognosis and survivorship.

Matching-adjusted indirect comparison from the Lymphoma Epidemiology of Outcomes Consortium for Real World Evidence (LEO CReWE) study to a clinical trial of mosunetuzumab in relapsed or refractory follicular lymphoma.

Mosunetuzumab is a novel bispecific antibody targeting epitopes on CD3 on T cells and CD20 on B cells with the goal of inducing T-cell mediated elimination of malignant B cells. A recent pivotal phase I/II clinical trial (GO29781) demonstrated that mosunetuzumab induced an overall response rate of 80%, complete response rate of 60%, and a median progression-free survival of 17.9 months in patients with relapsed/refractory (r/r) follicular lymphoma (FL) following at least two prior lines of systemic therapy, including alkylator and anti-CD20 antibody-based therapy. Historical data from cohorts receiving therapy for r/r FL can provide some context for interpretation of single-arm trials. We compared the results from the mosunetuzumab trial to outcomes from a cohort of patients with r/r FL from the LEO Consortium for Real World Evidence (LEO CReWE). We applied clinical trial eligibility criteria to the LEO CReWE cohort and utilized matching-adjusted indirect comparison weighting to balance the clinical characteristics of the LEO CReWE cohort with those from the mosunetuzumab trial. Overall response rates (73%, 95% CI:65-80%) and complete response rates (53%, 95% CI:45-61%) observed in the weighted LEO CReWE cohort were lower than those reported on the mosunetuzumab trial (ORR=80%, 95% CI:70-88%; CR=60%, 95% CI:49-70% respectively). Progression-free survival at 12 months was similar in the weighted LEO CReWE (60%, 95% CI:51-69%) and the mosunetuzumab trial (PFS 58%, 95% CI:47-68%). Sensitivity analyses examining the impact of matching variables, selection of line of therapy, and application of eligibility criteria, provide context for best practices in this setting.

A Young Boy With Hemophagocytic Lymphohistiocytosis Presenting With Vaccine-Related Granulomatous Dermatitis: A Case Report and Literature Review.

ABSTRACT: Cutaneous eruptions associated with hemophagocytic lymphohistiocytosis (HLH) have been reported in 6%-63% of patients. Clinical findings of these skin lesions vary widely and include maculopapular rashes, ulcers, and violaceous nodules. Corresponding histologic findings are also variable and are considered nonspecific. We report the case of a 4-year-old boy who initially developed a widespread popular-pustular rash 2 weeks after his 12-month measles, mumps, and rubella vaccinations. These resolved with scarring then recurred following his 24-month vaccinations. Multiple skin biopsies were negative for infectious organisms and showed a granulomatous infiltrate with perforation and necrobiosis. The differential diagnosis included perforating granuloma annulare, infection, or rheumatoid nodules. At the age of 4, he developed fever, hepatosplenomegaly, pancytopenia and other laboratory abnormalities, requiring hospitalization. A number of studies were performed including biopsies of bone marrow and liver. Molecular testing revealed 2 mutations in UNC13D known to be associated with familial HLH. His prior cutaneous lesions were likely caused by immune dysregulation exacerbated by immunizations because of underlying familial HLH. This case illustrates the importance of recognizing an unusual cutaneous manifestation of a rare disease to arrive at an earlier diagnosis in a pediatric patient. Although cutaneous eruptions usually develop concurrently with other systemic symptoms of HLH, preceding unusual skin lesions may be the first indication of this rare disease.

Acute lymphoblastic leukemia clonal distribution between bone marrow and peripheral blood.

Acute lymphoblastic leukemia (ALL) is often composed of numerous subclones. Here we test whether the clonal composition of the blood is representative of the bone marrow at leukemia onset. Using ultra-deep IGH sequencing, we detected 28 clones across 16 patients; 5/28 were only in the marrow. In four patients, the most abundant clones differed between sites, including three in which the dominant medullary clones were minimally detectable in the blood. These findings demonstrate that the peripheral blood often underrepresents the genetic heterogeneity in a B-ALL and highlight the potential impact of tissue site selection on the detection of minor subclones.

Transformed follicular non-Hodgkin lymphoma.

Histologic transformation of follicular lymphoma to an aggressive non-Hodgkin lymphoma is a critical biologic event with profound implications on the natural history of this otherwise indolent disease. Recent insights into the genetic and epigenetic basis of transformation have been described, with the recognition of pivotal events governing the initiation and persistence of tumor evolution. Outcomes of patients with transformed lymphoma have historically been poor; however, several studies in the rituximab era suggest that survival may be more favorable than previously recognized. This review highlights our current understanding of transformed follicular lymphoma biology and pathogenesis, current treatment, and future directions.

Phase II trial of R-CHOP plus bortezomib induction therapy followed by bortezomib maintenance for newly diagnosed mantle cell lymphoma: SWOG S0601.

Bortezomib is active in mantle cell lymphoma (MCL), with approval in upfront and relapsed settings. Given inevitable recurrence following induction chemoimmunotherapy, maintenance approaches are a rational strategy to improve clinical outcomes. We conducted a phase II study to evaluate the safety and efficacy of six cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) plus bortezomib (1.3 mg/m2 days 1 and 4 of 21 d cycles) followed by bortezomib maintenance (1.3 mg/m2 days 1, 4, 8, and 11 every 3 months for 2 years). Sixty-five eligible patients were enrolled. The treatment was well tolerated and toxicities were mainly haematological. The rate of grade ≥3 peripheral neuropathy was low (5%). With a median follow-up of 6.8 years, 2-year progression-free survival (PFS) was 62%, and 2-year overall survival (OS) was 85%. At 5 years, PFS was 28% and OS was 66%. MCL International Prognostic Index scores were significantly associated with 2-year PFS, but did not predict long-term (≥5-year) PFS. Baseline Ki-67 index was significantly associated with survival. Combination R-CHOP with bortezomib followed by maintenance bortezomib appears to improve outcomes compared historically with R-CHOP alone, with prolonged remissions in a subset of patients. These results suggest that inclusion of bortezomib with induction chemotherapy and/or maintenance is promising in MCL and warrants further exploration.

Combined comparative genomic hybridization and single-nucleotide polymorphism array detects cryptic chromosomal lesions in both myelodysplastic syndromes and cytopenias of undetermined significance.

The diagnosis of myelodysplastic syndrome (MDS) can be challenging, and may be facilitated by correlation with cytogenetic testing. Microarray analysis using comparative genomic hybridization and/or single-nucleotide polymorphism array can detect chromosomal abnormalities not seen by standard metaphase cytogenetics. We examined the ability of combined comparative genomic hybridization and single-nucleotide polymorphism analysis (hereafter referred to as 'combined array') to detect changes among 83 patients with unexplained cytopenias undergoing pathologic evaluation for MDS and compared results with 18 normal bone marrow controls. Thirty-seven patients (45%) were diagnosed with MDS, 12 patients (14%) were demonstrated to have 'indeterminate dyspoiesis' (insufficient for classification of MDS), 27 (33%) were essentially normal, and 7 patients (8%) had alternative pathologic diagnoses. Twenty-one MDS patients (57% of diagnoses) had effectively normal metaphase cytogenetics, but combined array showed that 5 of these (13% of MDS patients) harbored major cryptic chromosomal aberrations. Furthermore, nearly half of patients with 'indeterminate dyspoiesis' and 1 with normal morphology had clonal cytopenia(s) of undetermined significance by combined array analysis. Cryptic array findings among MDS patients and those with clonal cytopenias(s) included large-scale copy-neutral loss of heterozygosity (up to 118 Mb) and genomic deletion of loci implicated in MDS pathogenesis (eg, TET2 (4q22) and NUP98 (11p15)). By comparison, in MDS patients with abnormal metaphase cytogenetics, microarray mostly recapitulated findings seen by routine karyotype. Combined array analysis has considerable diagnostic yield in detecting cryptic chromosomal aberrations in MDS and in demonstrating aberrant clonal hematopoiesis in cytopenic patients with indeterminate morphologic dysplasia.

Intraclonal diversity in follicular lymphoma analyzed by quantitative ultradeep sequencing of noncoding regions.

Cancers are characterized by genomic instability, and the resulting intraclonal diversity is a prerequisite for tumor evolution. Therefore, metrics of tumor heterogeneity may prove to be clinically meaningful. Intraclonal heterogeneity in follicular lymphoma (FL) is apparent from studies of somatic hypermutation (SHM) caused by activation-induced deaminase (AID) in IGH. Aberrant SHM (aSHM), defined as AID activity outside of the IG loci, predominantly targets noncoding regions causing numerous "passenger" mutations, but it has the potential to generate rare significant "driver" mutations. The quantitative relationship between SHM and aSHM has not been defined. To measure SHM and aSHM, ultradeep sequencing (>20,000-fold coverage) was performed on IGH (~1650 nt) and nine other noncoding regions potentially targeted by AID (combined 9411 nt), including the 5' untranslated region of BCL2. Single-nucleotide variants (SNVs) were found in 12/12 FL specimens (median 136 SHMs and 53 aSHMs). The aSHM SNVs were associated with AID motifs (p < 0.0001). The number of SNVs at BCL2 varied widely among specimens and correlated with the number of SNVs at eight other potential aSHM sites. In contrast, SHM at IGH was not predictive of aSHM. Tumor heterogeneity is apparent from SNVs at low variant allele frequencies; the relative number of SNVs with variable allele frequency < 5% varied with clinical grade, indicating that tumor heterogeneity based on aSHM reflects a clinically meaningful parameter. These data suggest that genome-wide aSHM may be estimated from aSHM of BCL2 but not SHM of IGH. The results demonstrate a practical approach to the quantification of intratumoral genetic heterogeneity for clinical specimens.

Evolution to plasmablastic lymphoma evades CD19-directed chimeric antigen receptor T cells.

A patient with relapsed and refractory chronic lymphocytic leukaemia with Richter transformation was treated with chimeric antigen receptor (CAR)-modified T cells targeted for CD19 but later relapsed with a clonally related plasmablastic lymphoma. The loss of most routine markers of pre-plasma cell or B lymphoid differentiation (including CD19) highlights the ability of such mature lymphomas to evade lineage-specific targeted immunotherapy by differentiating along pathways comparable to their normal cellular counterparts. Molecular genetic evaluation demonstrated multiple independent lines of CD19-negative disease that eventually evolved in this single patient. Such plasticity represents potential challenges for antigen-directed CAR-T cell therapy, while serving as a testament to the selective pressure exerted by these engineered T cells over time.

R-CHOP with iodine-131 tositumomab consolidation for advanced stage diffuse large B-cell lymphoma (DLBCL): SWOG S0433.

Radiolabelled antiCD-20 antibodies have demonstrated single agent activity in relapsed diffuse large B-cell lymphoma (DLBCL). The S0433 clinical trial enrolled patients with newly diagnosed, advanced stage or bulky stage II, histologically confirmed DLBCL. Patients received six cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone), two cycles of CHOP, then iodine-131 tositumomab radioimmunotherapy consolidation 30-60 d after completion of chemotherapy. The primary endpoint was 2-year progression-free survival (PFS). Eighty-four eligible patients were enrolled, and 56 patients completed the entire course of protocol treatment. Of the 84 patients evaluable for treatment response, 72 [86%, 95% confidence interval (CI): 76-92%] achieved a partial response (n = 21) or a confirmed (n = 41) or unconfirmed (n = 10) complete response to therapy. With a median follow-up of 3·9 years, the 2-year PFS estimate is 69% and the 2-year overall survival estimate is 77%. Rituximab levels at time of radioimmunotherapy did not correlate with toxicity or outcome. Twenty percent of patients had double hit features (MYC+; BCL2+) by immunohistochemistry, and had inferior outcome. These current results suggest that the incorporation of novel agents earlier in therapy may ultimately have greater impact in DLBCL, as early progressions, deaths and declining performance status during CHOP chemotherapy limited the number of patients who ultimately could benefit from radioimmunotherapy consolidation.

A highly curable lymphoma occurs preferentially in the proximal tibia of young patients.

The presentation of two 19-year-old male subjects with stage I non-Hodgkin lymphoma in the proximal tibia prompted an extensive review of institutional and national databases to assess whether there is any statistical evidence that these reflected a previously overlooked syndromic pattern of presentation. The institutional records of a single institution were reviewed for presentation of non-Hodgkin lymphoma in the bone. The records of two additional institutions were reviewed for all reports of non-Hodgkin lymphoma in the tibia. Analysis was performed on data from Surveillance, Epidemiology, and End Results (SEER) dichotomized to bone presentation in the lower extremity versus other bones. Institutional databases included 20 patients with tibial presentation of lymphoma with a median age of 22.5 years (versus 42 for all bone lymphomas; P<0.001). Eighteen out of twenty patients had diffuse large B-cell lymphoma, and all patients aged ≤40 achieved remission and apparent cure. Distinctive and unusual features were a tendency for bilateral involvement of the tibia and sclerotic changes on X-ray. SEER data included 808 cases of bone lymphoma; the fraction of cases presenting in the lower extremity versus other bone sites is higher at ages ≤40 years (38% versus 19%; P<0.0001). Presentation in the lower extremity, as compared with other bone sites, confers 97% overall survival in patients aged ≤40 (versus 82%; P=0.01). This survival effect was independent of stage. In contrast, no significant difference in overall survival was identified for lower extremity versus non-lower extremity site for age >40. These data show a previously undescribed syndromic pattern of disease presentation: bone lymphoma in young patients is likely to present in the lower extremity-specifically the proximal tibia-has atypical sclerotic features on X-ray, is often bilateral, and has an excellent prognosis compared with bone lymphomas at other sites matched for stage and age.

Clonally unrelated primary large B-cell lymphomas separated by over a decade involving the central nervous system and testicle: Possible predisposition to lymphomas of immune-privileged sites?

Primary large B-cell lymphomas of immune-privileged sites (IP-LBCLs) comprise LBCLs arising within "immune sanctuaries," including the central nervous system (CNS), vitreoretina, and testes. Although patients present with localized disease, the prognosis remains poor with high relapse rates, either at the originating site or within another immune-privileged site. Generally, in the presence of an antecedent IP-LBCL, subsequent LBCLs are expected to be clonally related. However, we present a primary CNS LBCL and later primary testicular LBCL in a middle-aged man, diagnosed over a decade apart, which proved to be clonally unrelated by targeted ultra-deep next-generation sequencing of the IgH locus.

Epstein-Barr Virus Orchestrates Spatial Reorganization and Immunomodulation within the Classic Hodgkin Lymphoma Tumor Microenvironment.

Classic Hodgkin Lymphoma (cHL) is a tumor composed of rare malignant Hodgkin and Reed-Sternberg (HRS) cells nested within a T-cell rich inflammatory immune infiltrate. cHL is associated with Epstein-Barr Virus (EBV) in 25% of cases. The specific contributions of EBV to the pathogenesis of cHL remain largely unknown, in part due to technical barriers in dissecting the tumor microenvironment (TME) in high detail. Herein, we applied multiplexed ion beam imaging (MIBI) spatial pro-teomics on 6 EBV-positive and 14 EBV-negative cHL samples. We identify key TME features that distinguish between EBV-positive and EBV-negative cHL, including the relative predominance of memory CD8 T cells and increased T-cell dysfunction as a function of spatial proximity to HRS cells. Building upon a larger multi-institutional cohort of 22 EBV-positive and 24 EBV-negative cHL samples, we orthogonally validated our findings through a spatial multi-omics approach, coupling whole transcriptome capture with antibody-defined cell types for tu-mor and T-cell populations within the cHL TME. We delineate contrasting transcriptomic immunological signatures between EBV-positive and EBV-negative cases that differently impact HRS cell proliferation, tumor-immune interactions, and mecha-nisms of T-cell dysregulation and dysfunction. Our multi-modal framework enabled a comprehensive dissection of EBV-linked reorganization and immune evasion within the cHL TME, and highlighted the need to elucidate the cellular and molecular fac-tors of virus-associated tumors, with potential for targeted therapeutic strategies.

Follicular lymphoma tumor-infiltrating T-helper (T(H)) cells have the same polyfunctional potential as normal nodal T(H) cells despite skewed differentiation.

The follicular lymphoma (FL) T-cell microenvironment plays a critical role in the biology of this disease. We therefore determined the lineage, differentiation state, and functional potential of FL-infiltrating CD4(+) T-helper cells (T(H)) compared with reactive and normal lymph node (NLN) T(H) cells. Relative to NLNs, FL cells have decreased proportions of naive and central memory but increased proportions of effector memory T(H) cells. We further show differences in the distribution and anatomical localization of CXCR5(+) T(H) populations that, on the basis of transcription factor analysis, include both regulatory and follicular helper T cells. On Staphylococcus enterotoxin-B stimulation, which stimulates T cells through the T-cell receptor, requires no processing by APCs, and can overcome regulator T cell-mediated suppression, the proportion of uncommitted primed precursor cells, as well as T(H)2 and T(H)17 cells is higher in FL cells than in reactive lymph nodes or NLNs. However, the proportion of T(H)1 and polyfunctional T(H) cells (producing multiple cytokines simultaneously) is similar in FL cells and NLNs. These data suggest that, although T(H)-cell differentiation in FL is skewed compared with NLNs, FL T(H) cells should have the same intrinsic ability to elicit antitumor effector responses as NLN T(H) cells when tumor suppressive mechanisms are attenuated.