Transformed follicular lymphoma

An Endoscopic Ultrasound Diagnosis of a Rare Cause of Pancreatic Body Mass Demonstrating the Transformation to Large B-Cell Lymphoma

The presence of lymphoma in the gastrointestinal tract is most frequently manifested in the stomach and intestines. Pancreatic lymphomas consist of only 0.5% of all pancreatic neoplasms. In this case, we present a patient afflicted by follicular lymphoma with pancreatic involvement. To monitor the progression of this patient's lymphoma, endoscopic ultrasound was used to observe its transformation to large B-cell lymphoma and guide therapy.

AN UNUSUAL CASE OF PRIMARY VITREORETINAL LYMPHOMA: A TRANSFORMED LYMPHOMA

PURPOSE

To report a case of primary vitreoretinal lymphoma (VRL) presenting as diffuse large b-cell lymphoma 19 years after initial systemic follicular lymphoma.

METHOD

A case report.

RESULTS

An 81-year-old male patient presented with a 1-month history of floaters and blurry vision in the left eye. He had a history of follicular non-Hodgkin lymphoma treated with systemic chemotherapy in 2002 and prostate cancer treated surgically in 2004. Ophthalmic examination revealed vitritis, retinal whitening, perivascular sheathing, and a vascularized cream-colored retinal mass in the superonasal periphery of the left eye. Diagnostic vitrectomy with retina and vitreous biopsies demonstrated diffuse large b-cell lymphoma. Positron emission tomography/computed tomography confirmed the isolated lesion in the left eye without systemic involvement. Treatment with systemic and intraocular chemotherapy was planned.

CONCLUSION

To the best of our knowledge, this is the first reported case of primary vitreoretinal lymphoma of diffuse large b-cell lymphoma transformed from follicular lymphoma. Intravitreal and systemic chemotherapy, including rituximab, should be considered in the management of patients with transformed vitreoretinal lymphoma.

An Atypical relapsing follicular lymphoma to composite Hodgkin's lymphoma

Composite lymphoma is defined as two or more lymphomas with distinct morphological and immunophenotypical characteristics synchronously diagnosed at the same anatomical site. Composite lymphoma is rare, and the most common combination is follicular lymphoma (FL) associated with diffuse large B cell lymphoma, followed by FL associated with classic Hodgkin's lymphoma (HL). Histologically, composite lymphomas display a mixed pattern or distinct zonal distribution of each lymphoma component. Composite lymphoma poses a diagnostic challenge, especially when two lymphoma components are mixed in the same lymph node. Here, we report a case of composite HL and FL 11 years after initial and repeat biopsies consistent with FL in a man in his 70s emphasising the importance of repeat biopsy in lymphoma diagnosis.

Case Report: CD19 CAR T-cell therapy following autologous stem cell transplantation: a successful treatment for R/R CD20-negative transformed follicular lymphoma with TP53 mutation

Background

Follicular lymphoma (FL), a common indolent B-cell lymphoma, has the potential to transform into an aggressive lymphoma, such as diffuse large B-cell lymphoma (DLBCL). The outcome of patients with transformed follicular lymphoma (tFL) is poor, especially in patients with transformed lymphoma after chemotherapy and patients with progression within 24 months (POD24). Chimeric antigen receptor (CAR) T-cell therapy combined with autologous stem cell transplantation (ASCT) has promising antitumor efficacy.

Case presentation

Here, we described a 39-year-old male patient who was initially diagnosed with FL that transformed into DLBCL with POD24, CD20 negativity, TP53 mutation, and a bulky mass after 3 lines of therapy, all of which were adverse prognostic factors. We applied a combination approach: CD19 CAR T-cell infusion following ASCT. Ibrutinib was administered continuously to enhance efficacy, DHAP was administered as a salvage chemotherapy, and ICE was administered as a bridging regimen. The patient underwent BEAM conditioning on days -7~ -1, a total of 3.8 × 106/kg CD34+ stem cells were infused on days 01~02, and a total of 108 CAR T cells (relmacabtagene autoleucel, relma-cel, JWCAR029) were infused on day 03. The patient experienced grade 2 cytokine release syndrome (CRS), manifesting as fever and hypotension according to institutional standards. There was no immune effector cell-associated neurotoxicity syndrome (ICANS) after CAR T-cell infusion. Finally, the patient achieved CMR at +1 month, which has been maintained without any other adverse effects.

Conclusion

This case highlights the amazing efficacy of CD19 CAR T-cell therapy following ASCT for R/R tFL, thus providing new insight on therapeutic strategies for the future.

High-Throughput Drug Screen for Potential Combinations With Venetoclax Guides the Treatment of Transformed Follicular Lymphoma

Transformed follicular lymphoma (t-FL) is an aggressive malignancy that is refractory and rapidly progressing with poor prognosis. There is currently no effective treatment. High-throughput screening (HTS) platforms are used to profile the sensitivity or toxicity of hundreds of drug molecules, and this approach is applied to identify potential effective treatments for t-FL. We randomly selected a compound panel from the School of Pharmaceutical Sciences Xiamen University, tested the effects of the panel on the activity of t-FL cell lines using HTS and the CCK-8 assay, and identified compounds showing synergistic anti-proliferative activity with the Bcl-2 inhibitor venetoclax (ABT-199). Bioinformatics tools were used to analyze the potential synergistic mechanisms. The single-concentration compound library demonstrated varying degrees of activity across the t-FL cell lines evaluated, of which the Karpas422 cells were the most sensitive, but it was the cell line with the least synergy with ABT-199. We computationally identified 30 drugs with synergistic effects in all cell lines. Molecularly, we found that the targets of these 30 drugs didn't directly regulate Bcl-2 and identified 13 medications with high evidence value above .9 of coordination with ABT-199, further confirming TP53 may play the largest role in the synergistic effect. Collectively, these findings identified the combined regimens of ABT-199 and further suggested that the mechanism is far from directly targeting Bcl-2, but rather through the regulation and synergistic action of p53 and Bcl-2. This study intended to reveal the best synergistic scheme of ABT-199 through HTS to more quickly inform the treatment of t-FL.

Genetic subdivisions of follicular lymphoma defined by distinct coding and noncoding mutation patterns

Follicular lymphoma (FL) accounts for ∼20% of all new lymphoma cases. Increases in cytological grade are a feature of the clinical progression of this malignancy, and eventual histologic transformation (HT) to the aggressive diffuse large B-cell lymphoma (DLBCL) occurs in up to 15% of patients. Clinical or genetic features to predict the risk and timing of HT have not been described comprehensively. In this study, we analyzed whole-genome sequencing data from 423 patients to compare the protein coding and noncoding mutation landscapes of untransformed FL, transformed FL, and de novo DLBCL. This revealed 2 genetically distinct subgroups of FL, which we have named DLBCL-like (dFL) and constrained FL (cFL). Each subgroup has distinguishing mutational patterns, aberrant somatic hypermutation rates, and biological and clinical characteristics. We implemented a machine learning-derived classification approach to stratify patients with FL into cFL and dFL subgroups based on their genomic features. Using separate validation cohorts, we demonstrate that cFL status, whether assigned with this full classifier or a single-gene approximation, is associated with a reduced rate of HT. This implies distinct biological features of cFL that constrain its evolution, and we highlight the potential for this classification to predict HT from genetic features present at diagnosis.

Survival by First-line Treatment Type and Timing of Progression Among Follicular Lymphoma Patients: A National Population-based Study in Sweden

In follicular lymphoma (FL), progression of disease ≤24 months (POD24) has emerged as an important prognostic marker for overall survival (OS). We aimed to investigate survival more broadly by timing of progression and treatment in a national population-based setting. We identified 948 stage II-IV indolent FL patients in the Swedish Lymphoma Register diagnosed 2007-2014 who received first-line systemic therapy, followed through 2020. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated by first POD at any time during follow-up using Cox regression. OS was predicted by POD using an illness-death model. During a median follow-up of 6.1 years (IQR: 3.5-8.4), 414 patients experienced POD (44%), of which 270 (65%) occurred ≤24 months. POD was represented by a transformation in 15% of cases. Compared to progression-free patients, POD increased all-cause mortality across treatments, but less so among patients treated with rituximab(R)-single (HR = 4.54, 95% CI: 2.76-7.47) than R-chemotherapy (HR = 8.17, 95% CI: 6.09-10.94). The effect of POD was similar following R-CHOP (HR = 8.97, 95% CI: 6.14-13.10) and BR (HR = 10.29, 95% CI: 5.60-18.91). The negative impact of POD on survival remained for progressions up to 5 years after R-chemotherapy, but was restricted to 2 years after R-single. After R-chemotherapy, the 5-year OS conditional on POD occurring at 12, 24, and 60 months was 34%, 46%, and 57% respectively, versus 78%, 82%, and 83% if progression-free. To conclude, POD before but also beyond 24 months is associated with worse survival, illustrating the need for individualized management for optimal care of FL patients.

Investigating and modeling positron emission tomography factors associated with large cell transformation from low-grade lymphomas

Low-grade lymphomas have a 1%-3% annual risk of transformation to a high-grade histology, and prognostic factors remain undefined. We set to investigate the role of positron emission tomography (PET) metrics in identification of transformation in a retrospective case-control series of patients matched by histology and follow-up time. We measured PET parameters including maximum standard uptake value (SUV-max) and total lesion glycolysis (TLG), and developed a PET feature and lactate dehydrogenase (LDH)-based model to identify transformation status within discovery and validation cohorts. For our discovery cohort, we identified 53 patients with transformation and 53 controls with a similar distribution of follicular lymphoma (FL). Time to transformation and control follow-up time was similar. We observed a significant incremental increase in SUV-max and TLG between control, pretransformation and post-transformation groups (P < 0.05). By multivariable analysis, we identified a significant interaction between SUV-max and TLG such that SUV-max had highest significance for low volume cases (P = 0.04). We developed a scoring model incorporating SUV-max, TLG, and serum LDH with improved identification of transformation (area under the curve [AUC] = 0.91). Our model performed similarly for our validation cohort of 23 patients (AUC = 0.90). With external and prospective validation, our scoring model may provide a specific and noninvasive tool for risk stratification for patients with low-grade lymphoma.

Preclinical Studies of Chiauranib Show It Inhibits Transformed Follicular Lymphoma through the VEGFR2/ERK/STAT3 Signaling Pathway

Transformed follicular lymphoma (t-FL), for which there is no efficient treatment strategy, has a rapid progression, treatment resistance, and poor prognosis, which are the main reasons for FL treatment failure. In this study, we identified a promising therapeutic approach with chiauranib, a novel orally developed multitarget inhibitor targeting VEGFR/Aurora B/CSF-1R. We first determined the cytotoxicity of chiauranib in t-FL cell lines through CCK-8, EdU staining, flow cytometry, and transwell assays. We also determined the killing effect of chiauranib in a xenograft model. More importantly, we identified the underlying mechanism of chiauranib in t-FL tumorigenesis by immunofluorescence and Western blotting. Treatment with chiauranib significantly inhibited cell growth and migration, promoted apoptosis, induced cell cycle arrest in G2/M phase, and resulted in significant killing in vivo. Mechanistically, chiauranib suppresses the phosphorylation level of VEGFR2, which has an anti-t-FL effect by inhibiting the downstream MEK/ERK/STAT3 signaling cascade. In conclusion, chiauranib may be a potential therapy to treat t-FL, since it inhibits tumor growth and migration and induces apoptosis by altering the VEGFR2/ERK/STAT3 signaling pathway.

Diffuse large b-cell lymphoma of the ocular adnexa with flow cytometry analysis and review of the literature

PURPOSE

The aim of this study was to evaluate the clinicopathological features and flow cytometry (FCM) of tumor tissues in ocular adnexal diffuse large B-cell lymphoma (DLBCL).

METHODS

This retrospective, multicenter case study was designed to evaluate the clinical and immunohistochemical features of tumors. DLBCL was diagnosed based on histopathology, immunoglobulin (Ig) heavy chain gene rearrangement, and FCM in all surgically removed periocular tumor tissues. This study involved assessing percentages (%) of B-cell/T-cell markers, a natural killer cell marker, and cell-surface Ig kappa/lambda (κ/λ) expression measured by FCM analysis in tumor tissues.

RESULTS

Eleven DLBCL patients (4 men and 7 women) with 11 tumors were enrolled in this study. The median age at the time of initial presentation was 73 years. The tumor cells were immunohistochemically positive for cluster of differentiation (CD) 20, while CD5 was negative in all 8 cases tested. At the time of ophthalmic diagnosis, two cases already showed systemic dissemination of DLBCL throughout the body. FCM of tumor tissues detected a high percentage of B-cell markers including CD19 and CD20 in all 11 tumors. One case with high CD10 levels in FCM was histologic transformation from follicular lymphoma. One case with a relatively low CD20 population involved a history of systemic treatments including intravenous rituximab.

CONCLUSION

Although caution should be exercised when interpreting the data, FCM is useful for not only supportive diagnosis complementary to immunohistochemistry, but also facilitates a better understanding of immunopathology including histologic transformation of follicular lymphoma to DLBCL in the ocular adnexa.

Clinical usefulness of a novel classification of T cell distribution patterns in the tumor microenvironment of follicular lymphoma to detect transformation

The clinical course of follicular lymphoma (FL) is thought to be influenced by the infiltrating immune cells in the tumor microenvironment. Focusing on the distribution patterns of T cells may be a promising approach to estimate the prognosis of FL, especially histological transformation. This study was a retrospectively cohort study in the relationship between the pathological distribution pattern of T cells in the tumor microenvironment and clinical course of FL. One hundred twenty-eight patients with FL initially diagnosed at the University of Tokyo Hospital from January 2008 to January 2017 were evaluated. We classified each patient's specimen at initial diagnosis by the distribution pattern of tumor infiltrating CD3-positive cells, intra-follicle focal (IFF), intra-follicle diffuse (IFD), extra-follicle marginal (EFM), and extra-follicle diffuse (EFD). We analyzed the distribution pattern's correlation with other prognostic factors including overall survival (OS), progression free survival (PFS), and transformation. Among 128 cases, 81 had evaluable pathological specimen. Based on our criteria, in the intra-follicle,17 cases (21%) were classified as IFF. Sixty-four cases (79%) were classified as IFD. In the extra follicle, 25 cases (31%) were classified as EFM. Fifty-six cases (69%) were classified as EFD. There was significant difference in risk of transformation between the EFM and EFD around extra-follicle area in the adjusted model (p < 0.05). Also, cases with IFF and EFM had significantly higher risk of transformation compared to cases with other T cell distribution patterns (p < 0.01). We proposed a new classification of CD3-positive T cell distribution patterns around the follicle lesions in FL and demonstrated its clinical significance.

Six-Year Results From RELEVANCE: Lenalidomide Plus Rituximab (R2) Versus Rituximab-Chemotherapy Followed by Rituximab Maintenance in Untreated Advanced Follicular Lymphoma

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.

The RELEVANCE trial (ClinicalTrials.gov identifier: NCT01650701) showed that lenalidomide plus rituximab (R²) provided similar efficacy to rituximab plus chemotherapy (R-chemo) in patients with advanced-stage, previously untreated follicular lymphoma (FL). We report the second interim analysis of the RELEVANCE trial after 6 years of follow-up. Patients with previously untreated grade 1-3a FL were assigned 1:1 to R² or R-chemo, followed by rituximab maintenance. Coprimary end points were complete response (confirmed/unconfirmed) at week 120 and progression-free survival (PFS). At median follow-up of 72 months, 6-year PFS was 60% and 59% for R² and R-chemo, respectively (hazard ratio = 1.03 [95% CI, 0.84 to 1.27]). Six-year overall survival was estimated to be 89% in both groups. Median PFS and overall survival were not reached in either group. Overall response after progression was 61% and 59%, and 5-year estimated survival rate after progression was 69% and 74% in the R² and R-chemo groups, respectively. The transformation rate per year in the R² and R-chemo groups was 0.68% and 0.45%, and secondary primary malignancies occurred in 11% and 13% (P = .34), respectively. No new safety signals were observed. R² continues to demonstrate comparable, durable efficacy and safety versus R-chemo in previously untreated patients with FL and provides an acceptable chemo-free alternative.

Prediction of prognosis and pathologic grade in follicular lymphoma using 18F-FDG PET/CT

Purpose

We investigated the utility of a new baseline PET parameter expressing lesion dissemination and metabolic parameters for predicting progression-free survival (PFS) and pathologic grade in follicular lymphoma (FL).

Methods

The baseline ¹⁸F-FDG PET/CT images of 126 patients with grade 1–3A FL were retrospectively analyzed. A novel PET/CT parameter characterizing lesion dissemination, the distance between two lesions that were furthest apart (D_max), was calculated. The total metabolic tumor volume and total lesion glycolysis (TLG) were computed by using 41% of the maximum standardized uptake value (SUV_max) thresholding method.

Results

The 5-year PFS rate was 51.9% for all patients. In the multivariate analysis, high D_max [P = 0.046; hazard ratio (HR) = 2.877], high TLG (P = 0.004; HR = 3.612), and elevated serum lactate dehydrogenase (P = 0.041; HR = 2.287) were independent predictors of PFS. A scoring system for prognostic stratification was established based on these three adverse factors, and the patients were classified into three risk categories: low risk (zero to one factor, n = 75), intermediate risk (two adverse factors, n = 29), and high risk (three adverse factors, n = 22). Patients in the high-risk group had a shorter 3-year PFS (21.7%) than those in the low- and intermediate-risk groups (90.6 and 44.6%, respectively) (P < 0.001). The C-index of our scoring system for PFS (0.785) was superior to the predictive capability of the Follicular Lymphoma International Prognostic Index (FLIPI), FLIPI2, and PRIMA-Prognostic Index (C-index: 0.628–0.701). The receiver operating characteristic curves and decision curve analysis demonstrated that the scoring system had better differentiation and clinical utility than these existing indices. In addition, the median SUV_max was significantly higher in grade 3A (36 cases) than in grades 1 and 2 FL (90 cases) (median: 13.63 vs. 11.45, P = 0.013), but a substantial overlap existed (range: 2.25–39.62 vs. 3.17–39.80).

Conclusion

TLG and D_max represent two complementary aspects of the disease, capturing the tumor burden and lesion dissemination. TLG and D_max are promising metrics for identifying patients at a high risk of progression or relapse. Additionally, SUV_max seems to have some value for distinguishing grade 3A from low-grade FL but cannot substitute for biopsy.

[Clinical features and outcomes of newly diagnosed follicular lymphoma concurrent with diffuse large B-cell lymphoma component]

Objective: To explore the clinical features and survival of newly diagnosed follicular lymphoma (FL) patients with diffuse large B-cell lymphoma (DLBCL) component. Methods: 1845 newly diagnosed FL patients aged ≥ 18 years with grades 1-3a in 11 medical centers in China from 2000 to 2020 were included, and patients with DLBCL component were screened. The clinical data and survival data of the patients were retrospectively analyzed, and the prognostic factors were screened by univariate and multivariate analysis. Results: 146 patients (7.9% ) with newly diagnosed FL had DLBCL component. The median age was 56 (25-83) years, 79 males (54.1% ) . The pathology of 127 patients showed the proportion of DLBCL component. Patients were divided into two groups according to whether the proportion of DLBCL component was ≥ 50% . The study found that patients with DLBCL component ≥ 50% had higher grade 3 ratio (94.3% vs 91.9% , P=0.010) , Ki-67 index ≥ 70% ratio (58.5% vs 32.9% , P=0.013) and PET-CT SUVmax ≥ 13 ratio (72.4% vs 46.3% , P=0.030) than patients with DLBCL component<50% . All patients received CHOP or CHOP like ± rituximab chemotherapy. The overall response rate (ORR) was 88.2% , and the complete response (CR) rate was 76.4% . In the groups with different proportions of DLBCL component, there was no significant difference in the remission rate after induction treatment and the incidence of disease progression within 2 years after initiation of treatment (POD24) (P<0.05) . The overall estimated 5-year progression free survival (PFS) rate was 58.9% , and the 5-year overall survival (OS) rate was 90.4% . The 5-year OS rate of POD24 patients was lower than that of non POD24 patients (70.3% vs 98.5% , P<0.001) . Compared with non maintenance treatment of rituximab, maintenance treatment of rituximab could not benefit the 5-year PFS rate (57.7% vs 58.8% , P=0.543) , and the 5-year OS rate had a benefit trend, but the difference was not statistically significant (100% vs 87.8% , P=0.082) . Multivariate analysis showed that failure to reach CR after induction treatment was an independent risk factor for PFS (P=0.006) , while LDH higher than normal was an independent risk factor for OS (P=0.031) . Conclusion: FL patients with DLBCL component ≥50% have more invasive clinical and pathological features. CHOP/CHOP like ± rituximab regimen can improve the clinical efficacy of patients. Rituximab maintenance therapy can not benefit the PFS and OS of patients. Failure to reach CR after induction therapy was the independent unfavorable factor for PFS.

Screening of Adverse Prognostic Factors and Construction of Prognostic Index in Previously Untreated Concurrent Follicular Lymphoma and Diffuse Large B-Cell Lymphoma

Objective

Concurrent follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) (defined as FL/DLBCL) have been considered an important pathological feature in cell lymphoma. However, clinicopathological information and prognostic factors in these cases are scarce. The aim of this study was to construct a prediction index to compare with traditional prognostic models.

Methods

Retrospectively enrolled, previously untreated FL/DLBCL (n = 121) patients, as well as those with pure FL 1-3a (n = 471), were assessed. De novo DLBCL (n = 529) were used as controls. Kaplan-Meier curves were plotted to compare the outcomes among the three groups. Multivariate analysis identified risk factors associated with overall survival (OS) in FL/DLBCL patients. A clinicopathological prognosis index (CPPI) was developed to predict OS based on the Cox proportional hazards model.

Results

The outcomes of FL/DLBCL patients were intermediate between pure FL 1-3a and de novo DLBCL patients, with a 5-year PFS of 70%, 59%, and 48% (P < 0.05) and 5-year OS of 80%, 70% and 60% (P < 0.05), respectively. Cox regression analysis showed that the prognostic factors of OS for FL/DLBCL patients included FL grade, cell of origin, and Ann Arbor stage. A nomogram and clinicopathological prognostic index (CPPI) were developed to predict the OS for FL/DLBCL patients based on these factors. The area under the curve (AUC) of the CPPI for 3- and 5-year OS prediction was 0.782 and 0.860, respectively. This was superior to that of the International Prognostic Index (IPI), Follicular Lymphoma International Prognostic Index (FLIPI), and FLIPI2 in the 0.540-0.819 (P < 0.01) range.

Conclusions

A valid OS estimation in FL/DLBCL patients, using the recommended CPPI, may be useful in routine clinical practice.

Redefining the high‐grade B cell lymphoma with double/triple rearrangements of MYC and BCL2/BCL6 genes. Learning from a case report

We report a patient initially diagnosed with a triple hit high‐grade B cell lymphoma (HGBL‐TH), in which further morphologic, immunohistochemical, and next‐generation sequencing studies of subsequent specimens disclosed it to be a germinal center diffuse large B cell lymphoma (GC‐DLBCL) with BCL2/BCL6 gene translocations, PVT1‐deletion, and gain of MYC genes evolving from a previous follicular lymphoma. However, fluorescence in situ hybridization (FISH) studies with the break‐apart probe for MYC gene showed a fusion and two separated signals (red and green, respectively) leading to the interpretation of MYC gene translocation and a false diagnosis of a TH‐lymphoma, according to the recent WHO classification. Nevertheless, PVT1 deletion plus MYC gain/amplification has been described as a cause of the double‐hi transcription profile. These data highlight the need for new criteria to identify these highly aggressive lymphomas.

Dose escalation of subcutaneous epcoritamab in patients with relapsed or refractory B-cell non-Hodgkin lymphoma: an open-label, phase 1/2 study

BACKGROUND

Patients with relapsed or refractory B-cell non-Hodgkin lymphoma have few treatment options. We aimed to establish the safety and recommended phase 2 dose of epcoritamab, a novel bispecific antibody that targets CD3 and CD20 and induces T-cell-mediated cytotoxic activity against CD20+ malignant B cells.

METHODS

For the dose-escalation part of this phase 1/2 study, we enrolled adults (aged ≥18 years) with relapsed or refractory CD20+ B-cell non-Hodgkin lymphoma at ten sites across four countries (Denmark, the Netherlands, the UK, and Spain). Eligible patients received priming and intermediate doses followed by full doses of subcutaneous epcoritamab administered in 28-day cycles; each subsequent cohort involved escalation of the priming, intermediate, or full dose (0·0128-60 mg). The primary objectives were to determine the maximum tolerated dose and the recommended phase 2 dose. Safety, antitumour activity, pharmacokinetics, and immune biomarkers were also assessed. This study is registered with ClinicalTrials.gov, NCT03625037, with the dose-expansion part ongoing.

FINDINGS

Between June 26, 2018, and July 14, 2020, we enrolled 73 patients with relapsed, progressive, or refractory CD20+ mature B-cell non-Hodgkin lymphoma. 68 patients received escalating full doses (0·0128-60 mg) of subcutaneous epcoritamab. No dose-limiting toxic effects were observed, and the maximum tolerated dose was not reached; the full dose of 48 mg was identified as the recommended phase 2 dose. All 68 patients received at least one dose of epcoritamab and were included in safety analyses: common adverse events were pyrexia (47 patients [69%]), primarily associated with cytokine release syndrome (CRS; 40 [59%], all grade 1-2), and injection site reactions (32 [47%]; 31 grade 1). There were no grade 3 or higher CRS events. No discontinuations occurred due to treatment-related adverse events or treatment-related deaths. Overall response rate in patients with relapsed or refractory diffuse large B-cell lymphoma was 68% (95% CI 45-86), with 45% achieving a complete response at full doses of 12-60 mg. At 48 mg, the overall response rate was 88% (47-100), with 38% achieving a complete response. Patients with relapsed or refractory follicular lymphoma had an overall response rate of 90% (55-100), with 50% achieving a complete response at full doses of 0·76-48 mg. Epcoritamab induced robust and sustained B-cell depletion, and CD4+ and CD8+ T-cell activation and expansion, with modest increases in cytokine levels.

INTERPRETATION

Single-agent subcutaneous epcoritamab for treatment of patients with relapsed or refractory B-cell non-Hodgkin lymphoma merits investigation in ongoing phase 2 and phase 3 studies.

FUNDING

Genmab and AbbVie.

Diagnostic utility and prognostic significance of the Ki-67 labeling index in diffuse large B-cell lymphoma transformed from follicular lymphoma: a study of 76 patients

The diagnosis of histological transformation of follicular lymphoma can be challenging and ambiguous. We investigated the distribution of the Ki-67 labeling index of histological transformation of follicular lymphoma and determined its cutoff value to predict poor outcomes. The diagnostic criteria for histological transformation were a diffuse pattern of proliferation and a proportion of large lymphoma cells ≥20%. Of the 1121 patients with follicular lymphoma, 171 (15%) showed histological transformation to diffuse large B-cell lymphoma. Of these, 76 patients, whose biopsies were obtained from the sites with the highest maximum standardized uptake values, according to the positron emission tomography findings, were included. The Ki-67 index ranged from 16.8% to 98.4% (median, 60.6%). In patients with histological transformation, the most significant differences were found in progression-free survival (p = 0.087, 58% vs. 87% at 2 years) and overall survival (p = 0.024, 53% vs. 85% at 5 years) when a 70% cutoff was used. Additionally, overall survival was significantly shorter in patients with histological transformation with maximum standardized uptake values of ≥20 (p < 0.0001) and absence of a follicular lymphoma component (p = 0.004). A Ki-67 index of ≥70% was a significant adverse factor for overall survival in patients with histological transformation of follicular lymphoma and may predict poor outcomes.

R-CHOP intensification with mid-cycle methotrexate and consolidating AraC/TT with BCNU/aHSCT in primary aggressive lymphoma with CNS involvement

Purpose

Patients suffering from aggressive systemic peripheral lymphoma with primary central nervous system involvement (PCL) are a rare and sparsely investigated population. Recommended treatment regimens include a combination of intrathecal and systemic chemotherapy as well as whole brain radiotherapy while offering relatively poor survival.

Methods

We conducted a single-center retrospective study that analyzed safety and outcome of 4 + 4 cycles Rituximab (R)-CHOP and R-high-dose Methotrexate (HD-MTX) for newly diagnosed, transplant-eligible patients (“Ping-Pong”), followed by Cytarabine (AraC)/Thiotepa (TT), BCNU/TT, and autologous hematologic stem cell transplantation (aHSCT). We retrospectively analyzed a set of 16 patients with high–intermediate or high-risk IPI status.

Results

Overall response rate to Ping-Pong was 100% measured by CT/MRI, including 93.75% complete remissions after BCNU/TT followed by PBSCT. One patient failed to qualify for high-dose chemotherapy due to progression when receiving Cytarabine/TT. All patients experienced grade III adverse events, 3 of them a grade IV adverse event. Estimated progression-free survival is 93.75% after a 4.8-year follow-up currently.

Conclusion

Our study suggests high effectivity of R-CHOP with mid-cycle MTX with aHSCT consolidation towards acceptable OS results in this challenging patient population.

Relative frequency and clinicopathologic characteristics of MYC-rearranged follicular lymphoma

MYC rearrangement is a relatively rare genetic abnormality in follicular lymphoma (FL). In this study, we evaluated the relative frequency of MYC rearrangement in 522 cases of FL and studied their clinicopathologic, cytogenetic, and molecular characteristics. Fluorescence in situ hybridization studies for MYC (break-apart probe), MYC/IGH, IGH/BCL2, and BCL6 rearrangements were performed on tissue microarrays. Immunohistochemical stains for CD10, BCL2, BCL6, and MYC were performed and scored on MYC-rearranged cases. On 4 FL cases, a custom targeted panel of 356 genes was used for mutation analysis. Ten cases (1.9%) were positive for MYC rearrangement. Histologically, 6 of 10 cases were grade 1-2, and 4 cases were grade 3A. By immunohistochemistry, 9 of 9 tested cases were CD10+, all cases were BCL6+, and 9/10 cases were BCL2+. MYC protein staining was low in all cases tested. IGH/BCL2 rearrangement was detected in 5 of 9 cases, whereas BCL6 rearrangement was detected in 3 of 7 tested cases and 4 of 10 cases showed MYC/IGH rearrangement. The most commonly detected mutations in the MYC-positive cases included HLA-B, TNFRSF14, and KMT2D. MYC and/or B2M abnormalities were detected in 2 cases. In conclusion, MYC rearrangement is uncommon in FL and these cases do not appear to have specific histologic characteristics. Molecular analysis showed abnormalities in genes associated with transformation, namely MYC and B2M. Larger studies are needed to evaluate if MYC-rearrangement in FL has prognostic significance.

An analysis of genetic targets for guiding clinical management of follicular lymphoma

Introduction: Follicular lymphoma (FL) is one of the most common non-Hodgkin lymphoma (NHL) types, where genomic studies have accumulated potentially useful information about frequently mutated genes and deregulated pathways, which has allowed to a better understanding of the molecular pathogenesis of this tumor and the complex interrelationship between the tumoral cells and the stroma. Areas covered: The results of the molecular studies performed on Follicular Lymphoma have been here reviewed, summarizing the results of the clinical trials so far developed on this basis and discussing the reasons for the successes and failures. Searches were performed on June 1^st, 2020, in PubMed and ClinicalTrials.gov. Expert opinion: Targeted therapy for follicular lymphoma has multiple opportunities including the use of epigenetic drugs, PI3K inhibitors, modifiers of the immune stroma and others. Data currently known on FL pathogenesis suggest that combining these treatments with immunotherapy should be explored in clinical trials, mainly for patients with clinical progression or adverse prognostic markers. Association of targeted trials with dynamic molecular studies of the tumor and serum samples is advised. Chemotherapy-free approaches should also be explored as first-line therapy for FL patients.

Population-based epidemiological data of follicular lymphoma in Poland: 15 years of observation

Available epidemiological reports on follicular lymphoma (FL) often highlight a significant discrepancy between its high and low incidence rates in Western and Eastern Europe, respectively. The reasons behind that difference are not fully understood, but underreporting is typically presumed as one of the main factors. This study aimed to assess FL epidemiology in Poland based on 2000-2014 data from the Polish National Cancer Registry, which has 100% population coverage and over 90% completeness of the registration. All cases were coded according to ICD-10 and ICD-O-3 recommendations. The total number of registered FL cases was 3,928 with crude (CR) and standardized (SR) incidence rates of 0.72/10⁵ and 0.87/10⁵, respectively. The median age of FL diagnosis was 61 years, with the male to female incidence ratio of 1.06. The distribution of morphological types of FL: not otherwise specified (NOS), grades 1, 2, or 3 were 72.58, 4.81, 12.88, and 9.73%, respectively. Among all reported mature B-cell non-Hodgkin lymphomas, FL was ranked the fourth in incidence, just after chronic lymphocytic leukemia/small lymphocytic lymphoma (CR 3.62/10⁵, SR 4.99/10⁵), plasma cell neoplasms (CR 3.78/10⁵, SR 4.97/10⁵) and diffuse B-cell lymphoma, NOS (CR 2.13/10⁵, SR 2.65/10⁵). The systematic increase in FL incidence among females was observed. Our study confirms a lower FL incidence rate in Poland as compared to other European countries. Moreover, as our analysis was based on a registry with high data completeness, it provides evidence that reasons other than underreporting are responsible for FL incidence discrepancies between Eastern and Western Europe.

How to manage early-stage follicular lymphoma

INTRODUCTION

Early-stage follicular lymphoma (FL) is characterized by good prognosis and can be cured with involved-field radiotherapy (IF-RT) in most cases. PET scan is a milestone of diagnostic work-up, with the aim of identifying a truly localized disease; however, staging in most of the studies was without PET.

AREAS COVERED

We have searched in MEDLINE (inclusive dates 1994-2020) data about localized FL management. While high-quality evidence is lacking, current guidelines recommend IFRT or involved-site RT as first-line treatment in limited stages FL. Since a significant proportion of disease relapse occurred in non-irradiated areas, it has been hypothesized that occult disease could be present at diagnosis and could persist after RT, contributing to relapse. Available treatment options include watch-and-wait, chemotherapy, RT plus chemo- or chemo-immunotherapy, and RT combined with rituximab (R).

EXPERT OPINION

RT combined with chemotherapy could increase PFS, but a clear OS benefit is lacking and toxic effects could be unacceptable. A promising strategy is represented by R combined with IF-RT, with low relapse rate outside the radiation fields and without the toxicity reported with chemotherapy. The study of prognostic factors in PET-staged patients, the reduction of RT fields and doses, and a response-adapted strategy represent new perspectives to investigate.

Development of diffuse large B-cell lymphoma from duodenal type follicular lymphoma: a retrospective study of 23 cases

The incidence and clinical characteristics of histological transformation (HT) from duodenal type follicular lymphoma (DFL) are unclear. A retrospective analysis was conducted to identify the incidence and clinical features of HT from DFL in 23 cases with DFL. The median follow-up duration was 4.6 years (range, 0.8-20 years). HT to diffuse large B-cell lymphoma was observed in 2 of 23 cases during follow-up (8.7%). One of two cases transformed at 21 months later with increased serum lactate dehydrogenase (LDH; 1655 U/L) and abdominal lymphadenopathy. Partial response was achieved after R-THP (pirarubicin)-COP therapy, but the disease progressed. The other case transformed at 8.3 years with an increase of serum LDH (4022 U/L), abdominal lymphadenopathy, and bone marrow involvement. The disease was refractory to DA-EPOCH-R and a high-dose methotrexate/cytarabine regimen. The patient received allogenic peripheral blood stem cell transplantation and finally achieved complete response. Both cases developed HT at nodal or other intestinal lesions with no progression of the primary duodenal lesion. No significant factors for the occurrence of HT were identified. Although the incidence is low, HT could occur in DFL with aggressive clinical manifestations.

Initial Treatment of High Tumor Burden Follicular Lymphoma

Follicular lymphoma is the most common indolent B-cell lymphoma, with most patients presenting with advanced-stage disease. Patients who are symptomatic or otherwise meet the criteria for high tumor burden merit immediate intervention with combination immunochemotherapy, although more recently, "chemotherapy-free" approaches including novel therapies have shown benefit in this treatment-naïve population. In this review, the authors critically appraise the criteria for high tumor burden, the various options available for initial therapy, and the optimal post-treatment surveillance strategies.

Non-diffuse large B-cell lymphoma transformation from follicular lymphoma: a single-institution study of 19 cases

Diffuse large B-cell lymphoma (DLBCL) is the most common histological transformation (HT) of follicular lymphoma (FL). Other types of HT are very rare, and their incidence, histopathology, and patient outcomes have not been sufficiently described. Here, we assessed the clinicopathological characteristics of 19 cases of non-DLBCL HT of FL in a single institution in Japan to advance the understanding of the disease. Among 889 consecutive patients diagnosed with FL between 2000 and 2018, 191 suffered HT (21%). The median follow-up period was 94 months (range = 3-225). A total of 172 patients (90%) had DLBCL transformation, whereas the remaining 19 patients (10%) exhibited non-DLBCL transformation. In the latter cases, the following diagnoses were made based on morphology, immunohistochemistry, flow cytometry, and fluorescence in situ hybridization analyses: classic Hodgkin lymphoma (7 patients; 4%); high-grade B-cell lymphoma (HGBL) with MYC and BCL2 rearrangements (4 patients; 2%); HGBL, not otherwise specified (4 patients; 2%); B-cell lymphoblastic leukemia/lymphoma (2 patients; 1%); anaplastic large-cell lymphoma-like lymphoma (1 patient; 0.5%); and plasmablastic lymphoma (1 patient; 0.5%). Epstein-Barr virus-encoded RNA-1 did not associate with HT in any of the cases tested (n = 8). Patients with non-DLBCL transformation showed poor outcomes, with a median overall survival of 13 months (range = 2 days-107 months); 10 of the patients (53%) died of HT. In conclusions, non-DLBCL transformation was observed in 10% of patients with HT from FL. Our data show that timely, accurate, and comprehensive histopathological diagnosis is needed to ensure optimal treatment and improve the outcome of these patients.

B Cell Lymphoma

B cell development and activation are accompanied by dynamic genetic alterations including V(D)J rearrangements and immunoglobulin-gene somatic hypermutation and class-switch recombination. Abnormalities in these genetic events can cause chromosomal translocations and genomic mutations, leading to altered expression and function of genes involved in B cell survival or proliferation and consequently B lymphomagenesis. In fact, B cell lymphoma accounts for 95% of the lymphomas. In this chapter, we summarize the morphology, immunophenotypes, clinical features, genetic defects that cause the malignancies, treatments, and prognosis of the most prevalent types of B cell lymphomas, including typical precursor B cell malignance (B-ALL/LBL) and mature B cell lymphoma (Hodgkin lymphoma and B cell non-Hodgkin lymphoma).

Follicular lymphoma

Follicular lymphoma (FL) is a systemic neoplasm of the lymphoid tissue displaying germinal centre (GC) B cell differentiation. FL represents ~5% of all haematological neoplasms and ~20-25% of all new non-Hodgkin lymphoma diagnoses in western countries. Tumorigenesis starts in precursor B cells and becomes full-blown tumour when the cells reach the GC maturation step. FL is preceded by an asymptomatic preclinical phase in which premalignant B cells carrying a t(14;18) chromosomal translocation accumulate additional genetic alterations, although not all of these cells progress to the tumour phase. FL is an indolent lymphoma with largely favourable outcomes, although a fraction of patients is at risk of disease progression and adverse outcomes. Outcomes for FL in the rituximab era are encouraging, with ~80% of patients having an overall survival of >10 years. Patients with relapsed FL have a wide range of treatment options, including several chemoimmunotherapy regimens, phosphoinositide 3-kinase inhibitors, and lenalidomide plus rituximab. Promising new treatment approaches include epigenetic therapeutics and immune approaches such as chimeric antigen receptor T cell therapy. The identification of patients at high risk who require alternative therapies to the current standard of care is a growing need that will help direct clinical trial research. This Primer discusses the epidemiology of FL, its molecular and cellular pathogenesis and its diagnosis, classification and treatment.

Histological transformation in malignant lymphoma: a possible role of PET/CT and circulating tumor DNA as noninvasive diagnostic tools

Introduction: Transformation is a multi-step event wherein indolent lymphomas, such as follicular lymphomas, are converted into an aggressive subtype, such as diffuse large B-cell lymphoma. This process progresses not only through mutations in several of the causative genes, such as TP53, CDKN2A/B, or MYC, but also through epigenetic or micro-environmental changes. Excisional biopsy is recommended when transformation is clinically suspected.Areas covered: The authors summarized the current knowledge regarding the clinicopathological and molecular features of transformed lymphomas and discussed the relevance of re-biopsy in the diagnosis of transformation, comparing it with noninvasive diagnostic tools [fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) and circulating tumor DNA (ctDNA) analysis].Expert opinion: Pathological confirmation by biopsy is considered the golden standard for diagnosis and is indispensable for determining subsequent treatment strategies. The potential weakness of this approach is its invasiveness and the unavailability of pathological findings outside the biopsied areas. In the context of relapse, PET/CT is used mainly for the selection of the best suitable biopsy site, while ctDNA has the potential for detecting systemic genomic changes associated with relapse before clinical presentation. Future investigations should be focused on combining biopsies with new technologies for an early and accurate diagnosis of transformation.

Germinal Centre B Cell Functions and Lymphomagenesis: Circuits Involving MYC and MicroRNAs

BACKGROUND

The transcription factor MYC regulates several biological cellular processes, and its target gene network comprises approximately 15% of all human genes, including microRNAs (miRNAs), that also contribute to MYC regulatory activity. Although miRNAs are emerging as key regulators of immune functions, the specific roles of miRNAs in the regulation/dysregulation of germinal centre B-cells and B-cell lymphomas are still being uncovered. The regulatory network that integrates MYC, target genes and miRNAs is a field of intense study, highlighting potential pathways to be explored in the context of future clinical approaches.

METHODS

The scientific literature that is indexed in PUBMED was consulted for publications involving MYC and miRNAs with validated bioinformatics analyses or experimental protocols. Additionally, seminal studies on germinal centre B-cell functions and lymphomagenesis were reported.

CONCLUSIONS

This review summarizes the interactions between MYC and miRNAs through regulatory loops and circuits involving target genes in germinal centre B-cell lymphomas with MYC alterations. Moreover, we provide an overview of the understanding of the regulatory networks between MYC and miRNAs, highlighting the potential implication of this approach for the comprehension of germinal centre B-cell lymphoma pathogenesis. Therefore, circuits involving MYC, target genes and miRNAs provide novel insight into lymphomagenesis that could be useful for new improved therapeutic strategies.

Treatment Outcome in Patients with Primary or Secondary Transformed Indolent B-Cell Lymphomas

BACKGROUND

Histologic transformation (HT) of indolent B-cell lymphomas into an aggressive form can occur simultaneously (primary HT, pHT) or sequentially after a preceding diagnosis of indolent lymphoma (secondary HT, sHT). The clinical course after diagnosis of HT is variable.

OBJECTIVES

To describe the outcome of treatment in pHT and sHT patients.

METHODS

We retrospectively analyzed HT cases with an underlying follicular lymphoma, nodal marginal zone lymphoma, extranodal marginal zone lymphoma, lymphoplasmacytic lymphoma, or small lymphocytic lymphoma at our institution. Kaplan-Meier estimates were used to calculate progression-free survival (PFS) and overall survival (OS).

RESULTS

Ninety-two HT patients were identified, 38 with pHT and 54 with sHT. In sHT, time-to-transformation was not influenced by the preceding treatment strategy of the indolent lymphoma component. In pHT, median PFS was 61 months (95% CI 27-61), and OS was not reached. In sHT, median PFS and OS was 14 months (95% CI 9-32) and 42 months (95% CI 16-90), respectively. Significant differences between pHT and sHT in PFS (p = 0.002; Hazard ratio [HR] 2.30, 95% CI 1.36-3.91) and OS (p = 0.0001; HR 3.30, 95% CI 1.81-6.03) were observed. Response to treatment for transformation was highly prognostic of PFS and OS (p < 0.0001).

CONCLUSIONS

The outcome in pHT cases is favorable and signifi-cantly better than in sHT cases. Failure to achieve a remission after treatment for transformation confers a dismal pro-gnosis.

Characteristics, combinations, treatments, and survival of second primary hematological neoplasm: a retrospective single-center cohort of 49 patients (Hemo2study)

The coexistence of dual hematological neoplasms is very rare. Sequential or synchronous neoplasms in hematology are an uncommon and complex clinical situation. The aim of the Hemo² study was to describe the clinical characteristics and analyze the outcome of these patients. We performed a retrospective review of all patients diagnosed with sequential or synchronous hematological malignancies in the university hospital of Tours, between 2007 and 2018. We identified 49 patients in our study, with a prevalence of 0.89%. Sequential and synchronous combinations were found in 36 (73%) and 13 (27%) patients, respectively. One patient presented three sequential neoplasms. The median cumulative incidence was 6 years (95% CI 3-7). Among all neoplasms diagnosed (n = 99), we found 79 lymphoid neoplasms (LNs) (80%) and 20 myeloid neoplasms (MNs) (20%). Sex ratio was 1.88 with 65% of males and 35% of females. The most common LNs were Hodgkin lymphoma (n = 16; 16%) and multiple myeloma (n = 11; 11%). The most frequent MN was essential thrombocythemia (n = 5; 5%). The most common combination was Hodgkin lymphoma and follicular lymphoma in five (10%) patients. The overall survival from the first diagnosis (OS1) at 5 years was 82.4% (95% CI 72.1-94.3). The median overall survival from the second diagnosis (OS2) was 98 months (95% CI 44-NR) and 5-year OS2 was 58.7% (95% CI 45.5-75.7). Median progression-free survival from the second diagnosis (PFS) was 47 months (95% CI 27-NR) with 5-year PFS of 49% (95% CI 35.9-67). OS and PFS did not statistically differ between synchronous and sequential dual neoplasms. In this cohort, that the death relative risk (RR) was significantly lower if the second neoplasm appeared after more than 4 years following the first diagnosis (OR 0.37 (95% CI 0.16-0.90)). The Hemo²study confirmed the rarity of dual hematological neoplasms. In this cohort, HL and FL were the most frequent combinations. Our results may support that synchronous and sequential dual neoplasms bear the same prognosis. Further studies are needed to better characterize these uncommon clinical situations.

Immunoglobulin gene rearrangement IGHV3-48 is a predictive marker of histological transformation into aggressive lymphoma in follicular lymphomas

Follicular lymphoma (FL) is a heterogeneous disease whose pathogenesis remains partially unknown. Around 20% of FL patients experience early progression or treatment-refractory disease and 2–3% of patients per year experience histological transformation (HT) into a more aggressive lymphoma (tFL). Here, we evaluate the immunoglobulin heavy chain variable (IGHV) gene usage and mutational status in 187 FL cases to assess its impact on clinical outcome and histological transformation. The IGHV gene repertoire was remarkably biased in FL. The IGHV4-34 (14%), IGHV3-23 (14%), IGHV3-48 (10%), IGHV3-30 (9%) and IGHV3-21 (7%) genes accounted for more than half of the whole cohort. IGHV3-48 was overrepresented in cases of tFL (19%) compared with non-transformed FL at 5 years (5%, P = 0.05). Patients with the IGHV3-48 gene were significantly more likely to have had HT after 10 years than those who used other genes (71% vs. 25%, P < 0.05), irrespective of the therapy they received. Moreover, IGHV3-30 was also overrepresented in cases of FL (9%) and tFL (13%) compared with diffuse large B-cell lymphoma in which it was nearly absent. In conclusion, our results indicate a role for antigen selection in the development of FL, while the use of IGHV3-48 could help predict histological transformation.

A review of chimeric antigen receptor T-cells in lymphoma

Introduction: Immunotherapy has revolutionized the treatment of cancer. Antibodies, antibody drug conjugates, and bispecific antibodies have improved outcomes in various cancers especially lymphomas. Chimeric antigen receptor T cell (CAR-T) is a step forward in the immunotherapy paradigm for the treatment of Lymphomas. Recently, two CAR-T products, Tisagenlecleucel and Axicabtagene ciloleucel, were approved by the US FDA. While it is exciting to have such novel treatment available, the challenges of production, administration, related toxicity, and cost remain. Specific toxicities related to CAR-T like Cytokine Release Syndrome (CRS) and Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) could be fatal and need close monitoring and prompt treatment to avoid mortality and improve efficacy of the treatment. Areas covered: In this article, the authors discuss receptor constructs, administration, toxicities, efficacy and reimbursement of CAR-T treatment. Expert opinion: Since approval of CAR-T treatment, cost of therapy and reimbursement have been a big challenge in implementation of CAR-T. This has triggered cost-effective analysis and nationwide discussions about the reimbursement process of such treatment. In spite of these challenges, CAR-T treatment is a huge step forward with a very bright future. Novel CAR-T targeting a variety of antigens in different cancers seems promising in near future.

Histological transformation in duodenal-type follicular lymphoma: a case report and review of the literature

Duodenal-type follicular lymphoma (DFL) is a rare variant of follicular lymphoma (FL) characterized by distinctive clinical features such as localization and favorable prognosis. We herein report a case of DFL in which histological transformation into diffuse large B-cell lymphoma developed 7 years after diagnosis. The transformed lymphoma was refractory to chemotherapy, and the patient passed away due to disease progression. To date, there have been only a limited number of reported cases of histological transformation of DFL, and the clinical outcomes of those cases except our present case have been favorable, with good responses to chemotherapy. Although the histological transformation of DFL is a rare event, the clinical course of the present case suggested that it would be a fatal event and underscore the importance of the life-long management of DFL. Further accumulation of cases is required to elucidate its incidence, characteristics, and prognosis.

Transformed follicular lymphoma in the rituximab era: A report from the Spanish Lymphoma Oncology Group

Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma (NHL) subtype. The histological transformation (HT) of FL is an event considered frequent in the natural history of this tumor. We studied the transformation rates, predictive factors, and treatment characteristics that may impact in the survival of patients with FL and HT. A total of 1074 patients diagnosed with FL were prospectively enrolled from 1990 to 2016 in a Spanish registry. Sixty-four HTs were recorded based on clinical criteria (55%) or histological confirmation (45%). The cumulative incidence rate of transformation at 5 years is 7.3%. The 5-year overall survival (OS) without HT was 85% (95% confidence interval [CI], 70%-90%) vs 66% (95% CI, 51%-76%; P = 0.0012) with HT. Factors associated with HT were elevated lactate dehydrogenase (LDH) (odds ratio [OR] 1.83), intermediate-high Follicular lymphoma international prognostic index (FLIPI) (OR 2.16-OR 3.21), B symptoms (OR 2.46), or Eastern Cooperative Oncology Group (ECOG) 1 (OR 2.35). Treatment options related to HT were "watch and wait" or no rituximab or anthracyclines initially. A 5-year OS for patients treated with chemotherapy before HT was 55% (95% CI, 38%-69%) versus 81% (95% CI, 53%-93%; P = 0.009) for those who had not received it. The HT rate has decreased after the introduction of rituximab, as has been previously described. The timing of this treatment had an impact on the survival of these patients.

Chemotherapy-Free Initial Treatment of Advanced Indolent Lymphoma Has Durable Effect With Low Toxicity: Results From Two Nordic Lymphoma Group Trials With More Than 10 Years of Follow-Up

PURPOSE

For indolent lymphoma, the optimal timing, sequence, and choice of therapeutic regimens remain a matter of debate. In two Nordic Lymphoma Group randomized trials, symptomatic or clearly progressing patients were treated first line with a rituximab-containing regimen without chemotherapy. The purpose of this study was to assess long-term survival, risk of transformation, and need of new therapies.

METHODS

Data were collected at cross-sectional follow-up for 321 patients with indolent lymphoma (84% with follicular lymphomas [FL]) included in one of two Nordic Lymphoma Group trials (accrual 1998 to 1999 and 2002 to 2008). All patients received first-line therapy with one or two cycles of four weekly infusions of rituximab 375 mg/m2, and 148 were randomly allocated to the addition of interferon alfa-2a. Follow-up data were retrieved from initial trial databases and medical records on repeated clinical evaluations.

RESULTS

At the end of follow-up, 73% of patients were alive, with a median follow-up after random assignment of 10.6 years. Among all, 36% (38% with FL) had never needed chemotherapy. For patients with FL who required new therapy within 24 months because of early disease progression, the 10-year survival rate was 59% versus 81% for those with longer remission. Interferon was not shown to improve long-term outcome. Transformation was diagnosed in 20% of all patients (2.4% per person-year) and in 18% with FL. An additional malignancy was found in 12%.

CONCLUSION

Approximately one third of patients with symptomatic indolent lymphoma (30% with FL, 23% without FL) did not need new therapy in the long term after first-line rituximab without chemotherapy. In the entire cohort, 10-year survival was excellent with no major safety issues, which suggests that chemotherapy can be delayed safely in the majority of patients.

An update in treating transformed lymphoma

Indolent lymphomas typically have a prolonged course and favorable prognosis. Recent data support survival times that can reach several decades, even if periodic treatment is needed to manage symptoms or stabilize disease. However, all indolent lymphomas have the potential to undergo transformation to an aggressive phenotype, clinically characterized by a rapid progression of adenopathy, new-onset constitutional symptoms, or laboratory abnormalities, and the immediate need for therapeutic intervention. The most common scenario is transformation of follicular lymphoma to either diffuse large B-cell lymphoma or high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 translocations; however, other indolent subtypes such as marginal zone lymphoma, lymphoplasmacytic lymphoma, small lymphocytic lymphoma/chronic lymphocytic leukemia, or even nodular lymphocyte predominant Hodgkin lymphoma, can undergo similar histologic transformation. The prognosis of transformed lymphomas has historically been quite poor, but there is ample evidence this is changing in the rituximab era. This article will provide a review of transformed lymphomas with an emphasis on treatment and the nuances of diagnosis and clinical management. Unless otherwise specified, all discussion in this review pertains to transformed follicular lymphoma which is the more common scenario and the subtype with the most robust data. In many cases, this information can be extrapolated and applied to other indolent histologies (i.e. transformed marginal zone lymphoma); however, several other clinical scenarios, such as Richter's transformation and "double hit" transformations, warrant a distinct discussion and will be reviewed separately.

Pediatric-Type Follicular Lymphoma in the Dura: A Case Report and Literature Review

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a relatively common tumor of the central nervous system. Although PCNSLs generally arise from the parenchyma, lymphomas arising primarily from the dura are termed dural lymphomas (DLs). Mucosa-associated lymphoid tissue is the most unique histological feature of DLs. Because of its rarity, the clinical characteristics of and treatments for DL have not been fully elucidated to date.

CASE DESCRIPTION

A 31-year-old man with no past medical history presented with numbness in his left upper limb. Magnetic resonance imaging revealed a dural-based tumoral lesion and cervical lymphadenopathies. The lesion was diagnosed radiologically as a meningioma, and tumor resection was planned. However, an intraoperative pathological diagnosis showed neoplastic lymphocytes, and the planned total tumor resection was halted. Histologically, the tumor was characterized by areas of poorly defined follicular architecture consisting of medium and large centroblasts. These tumor cells were immunohistologically positive for CD10 and CD20 and negative for B-cell lymphoma (BCL) 2 and BCL6. Fluorescence in situ hybridization did not show evidence of an Immunoglobulin H/BCL2 fusion. The lesion was subsequently diagnosed as a pediatric-type follicular lymphoma (PTFL). Six cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) plus 2 cycles of rituximab were administered. The patient showed no evidence of relapse at 12 months after diagnosis, and follow-up was ongoing at the time of this report.

CONCLUSIONS

This very rare case of DL was originally diagnosed as a PTFL. The tumor could be treated by immunochemotherapy alone.