Prognostic implications of the microenvironment for follicular lymphoma under immunomodulation therapy

Evaluation of coverage, generalisability and validity of the U-CAN lymphoma biobank in Sweden: A comparison with nationwide registers

Validation of biobanks and large cancer cohorts is essential in ensuring high-quality research results. We examined the coverage, generalisability and validity of the lymphoma collection of the Uppsala-Umeå Comprehensive Cancer Consortium (U-CAN) biobank in Sweden, one of the largest cancer biobanks in Europe. Up until 2022, 889 lymphoma patients in U-CAN Uppsala had available samples, and 329 in U-CAN Umeå. Patients diagnosed in the U-CAN Uppsala area 2011-2021 (n = 843) were linked to the nationwide Swedish Lymphoma Register, and a subset diagnosed before 2019 (n = 727) to population-based registers. The coverage was 39% of all lymphoma patients between 2011 and 2019 diagnosed in the U-CAN Uppsala area, with a pandemic decline to 10% during 2020-2021. The patients included had superior overall survival (hazard ratio = 0.70 [95% confidence interval, CI: 0.60-0.82]) than all lymphoma patients in Sweden. They had better performance status, were younger (odds ratio [OR] = 0.21 [95% CI: 0.13-0.34]) and had less comorbidities (OR = 0.66 [95% CI: 0.56-0.78]). However, cause-specific survival and stage distribution were similar. The questionnaire data captured less comorbidities compared to the national registers. Evaluations of biobanks are important, as even population-based biobanks such as U-CAN select younger patients with higher socioeconomical status and better performance status. However, the similar cause-specific survival as in the registries suggests U-CANs usefulness for prognostic biomarker studies.

Analyzing the risk factors for disease progression within 2 years and histological transformation in patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone as first-line treatment: A 15-year follow-up of patients with advanced follicular lymphoma in JCOG0203

Follicular lymphoma (FL) is an indolent lymphoma that becomes aggressive due to histological transformation (HT), leading to reduced survival. Patients with FL have different clinical courses and various treatment options. Some patients exhibit shorter survival and experience disease progression within 24 months of diagnosis/treatment (POD24); the optimal treatment remains an unmet needs. Thus, identifying factors that predict shorter survival is essential to stratify treatment and prolong the survival of patients with FL. To analyze risk factors for POD24 and HT in patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) as first-line treatment, we performed this post-hoc analysis of patients with advanced indolent B-cell lymphoma in a randomized clinical trial wherein six cycles of R-CHOP were administered every 2-3 weeks. The primary analysis showed no differences in outcomes, which enabled the analysis of 248 patients with FL, assigned to two arms. All histopathological specimens from the 300 enrolled patients were reviewed by three expert hematopathologists. Multivariable analysis implicated Follicular Lymphoma International Prognostic Index (FLIPI) intermediate (odds ratio [OR] 2.531, 95% confidence interval [CI] 0.676-9.466) and high- (OR 2.236, 95% CI 0.160-31.226) risks, B symptoms (OR 2.091, 95% CI 0.747-5.851), and grade 3A (G3A) (OR 1.833, 95% CI 0.634-5.299) as risk factors for POD24. Furthermore, multivariable analysis through a median follow-up of 15.9 years implicated G3A (OR 2.628, 95% CI 0.806-8.575) and high-risk FLIPI (OR 4.401, 95% CI 0.186-104.377) as risk factors for HT. However, an analysis limited to the first 10 years revealed that the prognostic factors elucidated from the longer-term analysis had a greater impact on HT. G3A and high-risk FLIPI may independently predict POD24 and HT, thereby informing treatment stratification of patients with untreated advanced-stage FL in future trials, particularly to address the unmet needs of patients with POD24.

Targeting the immune microenvironment in mantle cell lymphoma: implications for current and emerging therapies

Mantle cell lymphoma (MCL) is a morphologically and phenotypically heterogeneous subtype of non-Hodgkin lymphoma, and has historically been associated with poor outcomes. However, recent advances in our understanding of this disease have yielded new targeted and immune-based therapies with promising activity. Immune-based therapies such as monoclonal antibodies, immunomodulators, and CAR T cells have significantly improved outcomes and are now standard of care in MCL. In this review, we describe our current understanding of the immune microenvironment of MCL, discuss current immunotherapeutic approaches, and highlight promising novel immune-based therapies and combination therapies that may further improve outcomes for patients with MCL.

Genetics of Transformed Follicular Lymphoma

Histological transformation (HT) to a more aggressive disease–mostly diffuse large B-cell lymphoma–is considered one of the most dismal events in the clinical course of follicular lymphoma (FL). Current knowledge has not found a single biological event specific for HT, although different studies have highlighted common genetic alterations, such as TP53 and CDKN2A/B loss, and MYC translocations, among others. Together, they increase genomic complexity and mutational burden at HT. A better knowledge of HT pathogenesis would presumably help to find diagnostic biomarkers allowing the identification of patients at high-risk of transformation, as well as the discrimination from patients with FL recurrence, and those who remain in remission. This would also help to identify new drug targets and the design of clinical trials for the treatment of transformation. In the present review we provide a comprehensive overview of the genetic events frequently identified in transformed FL contributing to the switch towards aggressive behaviour, and we will discuss current open questions in the field of HT.

Risk factors for POD24 in patients with previously untreated follicular lymphoma: a systematic review and meta-analysis

Progression of disease within 24 months (POD24) is strongly associated with a poor outcome in patients with follicular lymphoma (FL). Our study aimed to identify the potential risk factors for POD24 in patients with FL. Medline, EMBASE and the Cochrane Library were systematically searched from the earliest record to September 2020. Studies investigating the prognostic factors for POD24 in patients with newly diagnosed grade 1-3a FL were included. Among 10,014 pieces of literature, a total of 90 studies investigating 82 risk factors were included for qualitative analysis. Meta-analyses were performed in 31 studies with 11 factors. Results showed that elevated sIL-2R, β2m and LDH, total metabolic tumour volume > 510 cm³, vitamin D < 20 ng/mL, grade 3a and lymphoma-associated macrophages/high-power field ≥ 15 were significantly associated with an increased risk of POD24. No significant association was found between POD24 and the ALC/AMC ratio, sex, T effector signature or EZH2 genetic alteration. Additionally, minimal residual disease, Ki-67, PD-1 and TP53 were analysed narratively. Overall, this is the first study that comprehensively analysed the prognostic factors associated with POD24 in FL patients. We have confirmed the significance value of several common prognostic factors as well as others not commonly included in clinical study, helping to construct an integrated and more efficient model.

H3K27m3 overexpression as a new, BCL2 independent diagnostic tool in follicular and cutaneous follicle center lymphomas

Approximately 15% of follicular lymphomas (FL) lack overexpression of BCL2 and the underlying translocation t(14;18). These cases can be diagnostically challenging, especially regarding follicular hyperplasia (FH). In a subset of FL, mutations in genes encoding for epigenetic modifiers, such as the histone-lysine N-methyltransferase EZH2 (enhancer of zeste homolog 2), were found, which might be used diagnostically. These molecular alterations can lead to an increased tri-methylation of histone H3 at position lysine 27 (H3K27m3) that, in turn, can be visualized immunohistochemically. The aim of this study was to analyze the expression of H3K27m3 in FL, primary cutaneous follicle center lymphomas (PCFCL), and pediatric-type FL (PTFL) in order to investigate its value in the differential diagnosis to FH and other B cell lymphomas and to correlate it to BCL2 expression and the presence of t(14;18). Additionally, the mutational profile of selected cases was considered to address H3K27m3’s potential use as a surrogate parameter for mutations in genes encoding for epigenetic modifiers. Eighty-nine percent of FL and 100% of PCFCL cases overexpressed H3K27m3, independently of BCL2, EZH2, and the presence of mutations. In contrast, 95% of FH and 100% of PTFL cases lacked H3K27m3 overexpression. Other B cell lymphomas considered for differential diagnosis also showed overexpression of H3K27m3 in the majority of cases. In summary, overexpression of H3K27m3 can serve as a new, BCL2 independent marker in the differential diagnosis of FL and PCFCL, but not PTFL, to FH, while being not of help in the differential diagnosis of FL to other B cell lymphomas.

An Immune-Clinical Prognostic Index (ICPI) for Patients With De Novo Follicular Lymphoma Treated With R-CHOP/CHOP Chemotherapy

Purpose

Although the role of tumor-infiltrating T cells in follicular lymphoma (FL) has been reported previously, the prognostic value of peripheral blood T lymphocyte subsets has not been systematically assessed. Thus, we aim to incorporate T-cell subsets with clinical features to develop a predictive model of clinical outcome.

Methods

We retrospectively screened a total of 1,008 patients, including 252 newly diagnosed de novo FL patients with available peripheral blood T lymphocyte subsets who were randomized to different sets (177 in the training set and 75 in the internal validation set). A nomogram and a novel immune-clinical prognostic index (ICPI) were established according to multivariate Cox regression analysis for progression-free survival (PFS). The concordance index (C-index), Akaike’s information criterion (AIC), and likelihood ratio chi-square were employed to compare the ICPI’s discriminatory capability and homogeneity to that of FLIPI, FLIPI2, and PRIMA-PI. Additional external validation was performed using a dataset (n = 157) from other four centers.

Results

In the training set, multivariate analysis identified five independent prognostic factors (Stage III/IV disease, elevated lactate dehydrogenase (LDH), Hb <120g/L, CD4+ <30.7% and CD8+ >36.6%) for PFS. A novel ICPI was established according to the number of risk factors and stratify patients into 3 risk groups: high, intermediate, and low-risk with 4-5, 2-3, 0-1 risk factors respectively. The hazard ratios for patients in the high and intermediate-risk groups than those in the low-risk were 27.640 and 2.758. The ICPI could stratify patients into different risk groups both in the training set (P < 0.0001), internal validation set (P = 0.0039) and external validation set (P = 0.04). Moreover, in patients treated with RCHOP-like therapy, the ICPI was also predictive (P < 0.0001). In comparison to FLIPI, FLIPI2, and PRIMA-PI (C-index, 0.613-0.647), the ICPI offered adequate discrimination capability with C-index values of 0.679. Additionally, it exhibits good performance based on the lowest AIC and highest likelihood ratio chi-square score.

Conclusions

The ICPI is a novel predictive model with improved prognostic performance for patients with de novo FL treated with R-CHOP/CHOP chemotherapy. It is capable to be used in routine practice and guides individualized precision therapy.

Lenalidomide triggers T-cell effector functions in vivo in patients with follicular lymphoma

The immunomodulatory drug lenalidomide is used in patients with follicular lymphoma (FL) with the aim of stimulating T-cell antitumor immune response. However, little is known about the effects of lenalidomide on T-cell biology in vivo in patients with FL. We thus undertook an extensive longitudinal immunologic study, including phenotypic, transcriptomic, and functional analyses, on 44 first-line and 27 relapsed/refractory patients enrolled in the GALEN trial (Obinutuzumab Combined With Lenalidomide for Relapsed or Refractory Follicular B-Cell Lymphoma) to test the efficacy of lenalidomide and obinutuzumab combination in patients with FL. Lenalidomide rapidly and transiently induced an activated T-cell phenotype, including HLA-DR, Tim-3, CD137, and programmed cell death protein 1 (PD-1) upregulation. Furthermore, sequential RNA-sequencing of sorted PD-1+ and PD-1- T-cell subsets revealed that lenalidomide triggered a strong enrichment for several gene signatures related to effector memory T-cell features, including proliferation, antigen receptor signaling, and immune synapse restoration; all were validated at the phenotypic level and with ex vivo functional assays. Correlative analyses pinpointed a negative clinical impact of high effector T-cell and regulatory T-cell percentages before and during treatment. Our findings bring new insight in lenalidomide mechanisms of action at work in vivo and will fuel a new rationale for the design of combination therapies.

Effects of lenalidomide on the bone marrow microenvironment in acute myeloid leukemia: Translational analysis of the HOVON103 AML/SAKK30/10 Swiss trial cohort

This translational study aimed at gaining insight into the effects of lenalidomide in acute myeloid leukemia (AML). Forty-one AML patients aged 66 or older of the Swiss cohort of the HOVON-103 AML/SAKK30/10 study were included. After randomization, they received standard induction chemotherapy with or without lenalidomide. Bone marrow biopsies at diagnosis and before the 2nd induction cycle were obtained to assess the therapeutic impact on leukemic blasts and microenvironment. Increased bone marrow angiogenesis, as assessed by microvessel density (MVD), was found at AML diagnosis and differed significantly between the WHO categories. Morphological analysis revealed a higher initial MVD in AML with myelodysplasia-related changes (AML-MRC) and a more substantial decrease of microvascularization after lenalidomide exposure. A slight increase of T-bet-positive TH1-equivalents was identifiable under lenalidomide. In the subgroup of patients with AML-MRC, the progression-free survival differed between the two treatment regimens, showing a potential but not significant benefit of lenalidomide. We found no correlation between the cereblon genotype (the target of lenalidomide) and treatment response or prognosis. In conclusion, addition of lenalidomide may be beneficial to elderly patients suffering from AML-MRC, where it leads to a reduction of microvascularization and, probably, to an intensified specific T cell-driven anti-leukemic response.

The tumor microenvironment of lymphomas: Insights into the potential role and modes of actions of checkpoint inhibitors

The tumor microenvironment (TME) - a term comprising non-neoplastic cells and extracellular matrix as well as various cytokines, chemokines, growth factors, and other substances in the vicinity of tumor cells - is an integrative part of most tumors including lymphomas. Interactions between lymphoma cells and the TME are vital for survival and proliferation of the former. In addition, lymphoma cells often reprogram the TME to protect them from defense mechanisms of the host's immune system. In this review, we will introduce the role of the tumor microenvironment (TME) for lymphoma cells looking at direct cell-cell interactions as well as cytokine-related communications. The immunomodulative/immunosuppressive role of the TME is more and more coming into the focus of potential new targeted therapies, and thus a special attention will be given to the interactions of immune checkpoints such as programed cell death protein 1 and L1 (PD-1/PD-L1), T-cell immunoglobulin and mucin-domain containing protein-3 (TIM-3), lymphocyte-activation gene 3 (LAG-3), and cytotoxic T-lymphocyte-associated protein-4 (CTLA4) with the TME, as well as their expression by both lymphoma cells and cells of the TME. Aspects of the TME will be discussed for indolent and aggressive B-cell lymphomas, Hodgkin lymphomas, and T-cell lymphomas. In addition, the potential influence of other immunomodulators such as lenalidomide will be briefly touched. The complex role of the TME is in the focus of new therapeutic options. In order to exploit its full therapeutic potential, however, a thorough understanding of TME biology and interaction between lymphoma cells and the TME, as well as the host's immune system and the TME is necessary.

Precision medicine in follicular lymphoma: Focus on predictive biomarkers

Current care for patients with follicular lymphoma (FL) offers most of them long-term survival. Improving it further will require careful patient selection. This review focuses on predictive biomarkers (ie, those whose outcome correlations depend on the treatment strategy) in FL, because awareness of what patient subsets benefit most or least from each therapy will help in this task. The first part of this review aims to summarize what biomarkers are predictive in FL, the magnitude of the effect and the quality of the evidence. We find predictive biomarkers in the setting of (a) indication of active treatment, (b) front-line induction (use of anthracyline-based regimens, CHOP vs bendamustine, addition of rituximab), (c) post-(front-line)induction (rituximab maintenance, radioimmunotherapy), and (d) relapse (hematopoietic stem cell transplant) and targeted agents. The second part of this review discusses the challenges of precision medicine in FL, including (a) cost, (b) clinical relevance considerations, and (c) difficulties over the broad implementation of biomarkers. We then provide our view on what biomarkers may become used in the next few years. We conclude by underscoring the importance of assessing the potential predictiveness of available biomarkers to improve patient care but also that there is a long road ahead before reaching their broad implementation due to remaining scientific, technological, and economic hurdles.

An integrative microenvironment approach for follicular lymphoma: roles of inflammatory cell subsets and immune-response polymorphisms on disease clinical course

The study of the tumor microenvironment (TME) in follicular lymphoma (FL) has produced conflicting results due to assessment of limited TME subpopulations, and because of heterogeneous treatments among different cohorts. Also, important genetic determinants of immune response, such as single-nucleotide polymorphisms (SNPs), remain underexplored in this disease. We performed a detailed study of the TME in 169 FL biopsies using immunohistochemistry, encompassing lymphocytes, macrophages, and cytokines. We also genotyped 16 SNPs within key immune-response genes (IL12A, IL2, IL10, TGFB1, TGFBR1, TGFBR2, IL17A, and IL17F) in 159 patients. We tested associations between SNPs, clinicopathological features and TME composition, and proposed survival models in R-CHOP/R-CVP-treated patients. Presence of the IL12A rs568408 "A" allele associated with the follicular pattern of FOXP3+ cells. The IL12A AA haplotype included rs583911 and rs568408 and was an independent predictor of worse survival, together with the follicular patterns of T-cells (FOXP3+ and CD8+) and high IL-17F tumor levels. The patterns of CD3+, CD4+ and CD8+ cells, displayed as a principal component, also associated with survival. Hierarchical clustering of the TME proteins demonstrated a cluster that was associated with worse prognosis (tumors enriched in IL-17A, IL-17F, CD8, PD1, and Ki-67). The survival of FL patients who were treated in the rituximab era shows a strong dependence on TME signals, especially the T-cell infiltration patterns and IL-17F tumor levels. The presence of the AA haplotype of IL12A in the genome of FL patients is an additional prognostic factor that may modulate the composition of T-reg cells in this disease.