Tumour-immune microenvironment in duodenal-type follicular lymphoma

The Role of Small Bowel Capsule Endoscopy in Determining the Treatment Strategy for Duodenal Follicular Lymphoma: A Single-Center Retrospective Study

Objectives: In this single-center retrospective study, we aimed to verify the extent of duodenal follicular lymphoma (DFL) and investigate the role and clinical significance of video capsule endoscopy (VCE) in the treatment process. Methods: We analyzed the clinical and imaging data of 40 patients diagnosed with DFL. Results: Imaging workup and bone marrow biopsies revealed DFL only in the gastrointestinal tract (stage I) in 22 patients and in local lymph nodes (stage II1), distant lymph nodes (stage II2), pancreas (stage II2Epancreas), and extranodal regions (stage IV) in 1, 3, 1, and 13 patients, respectively. Fifteen of the 23 patients with localized (stages I and II1) DFL underwent VCE for comprehensive small bowel evaluation, which revealed lesion extension beyond the duodenum in 10 patients (66.7%). A watch-and-wait strategy was implemented for one patient and systemic chemotherapy was administered to the remaining nine. Of the eight patients without VCE, seven and one received radiotherapy and observation, respectively. Nine of the 23 patients (39.1%) received systemic treatment based on positive VCE results. Only one of the 17 patients with advanced-stage DFL (stages II2 and IV) accepted radiotherapy; 16 underwent systemic chemotherapy. During follow-up (median, 48.4 months), two relapse events occurred in the advanced stage, with no lymphoma-associated deaths. DFL tends to be indolent and has favorable outcomes. Conclusions: Proactive VCE for diagnosing DFL is recommended to determine small bowel involvement, which may influence subsequent treatment decisions.

Clinical characteristics and outcomes of Brazilian patients with duodenal-type follicular lymphoma: a multicenter retrospective study

Duodenal-type follicular lymphoma (DFL) is a rare subtype classified by the 5th edition of the WHO and international consensus classifications of lymphoid neoplasms, typically presenting as localized disease with favorable outcomes. This multicenter retrospective study examines 53 Brazilian DFL patients with a median age of 58.2 years (33-85), with males comprising 50% (n = 27). According to Lugano GI tract classification, 40 patients (75%) were stage I. Median follow-up was 2.9 years (range 0.1-11). Incidental diagnosis occurred in 28 patients (52.8%) during routine endoscopy; 24 patients (45%) presented mild gastrointestinal symptoms. Treatments included watchful waiting (32 patients, 60.4%), rituximab monotherapy (15 patients, 28.3%), radiotherapy (three patients, 5.7%), and chemoimmunotherapy (three patients, 5.7%). Three patients experienced disease progression; watchful waiting showed three spontaneous remissions. No deaths occurred during follow-up. This study, the first from Latin America, demonstrates a good prognosis across treatments, highlighting Watchful waiting's effectiveness.

Recent updates on treatment options for primary follicular lymphoma of the gastrointestinal tract

BACKGROUND

Primary gastrointestinal follicular lymphoma is a subtype of follicular lymphoma that originates directly from the gastrointestinal tract. Pathologically, it exhibits substantial similarities with the secondary gastrointestinal involvement observed in nodal follicular lymphoma. However, primary gastrointestinal follicular lymphoma presents clinically distinct features, necessitating divergent considerations in treatment selection compared with nodal follicular lymphoma.

AREAS COVERED

This narrative review focused on recent articles (2018-2023) regarding the long-term prognosis and treatment options for gastrointestinal follicular lymphoma. In addition, a brief overview of gastrointestinal follicular lymphomas is provided.

EXPERT OPINION

Patients with primary gastrointestinal follicular lymphoma often present with a low tumor burden. Lymphoma lesions typically remain asymptomatic for several years or may undergo spontaneous regression without immediate treatment. Therefore, a 'watch and wait' approach is justified. Conversely, when large tumor masses are identified in the gastrointestinal tract, the potential for tumor bleeding or intestinal obstruction requires timely therapeutic interventions.

Cell cross talk within the lymphoma tumor microenvironment: follicular lymphoma as a paradigm

ABSTRACT

Follicular lymphoma (FL) is an indolent yet incurable germinal center B-cell lymphoma retaining a characteristic follicular architecture. FL tumor B cells are highly dependent on direct and indirect interactions with a specific and complex tumor microenvironment (TME). Recently, great progress has been made in describing the heterogeneity and dynamics of the FL TME and in depicting how tumor clonal and functional heterogeneity rely on the integration of TME-related signals. Specifically, the FL TME is enriched for exhausted cytotoxic T cells, immunosuppressive regulatory T cells of various origins, and follicular helper T cells overexpressing B-cell and TME reprogramming factors. FL stromal cells have also emerged as crucial determinants of tumor growth and remodeling, with a key role in the deregulation of chemokines and extracellular matrix composition. Finally, tumor-associated macrophages play a dual function, contributing to FL cell phagocytosis and FL cell survival through long-lasting B-cell receptor activation. The resulting tumor-permissive niches show additional layers of site-to-site and kinetic heterogeneity, which raise questions about the niche of FL-committed precursor cells supporting early lymphomagenesis, clonal evolution, relapse, and transformation. In turn, FL B-cell genetic and nongenetic determinants drive the reprogramming of FL immune and stromal TME. Therefore, offering a functional picture of the dynamic cross talk between FL cells and TME holds the promise of identifying the mechanisms of therapy resistance, stratifying patients, and developing new therapeutic approaches capable of eradicating FL disease in its different ecosystems.

Duodenal Follicular Lymphoma: Track or Treat?

Duodenal follicular lymphoma (DFL) is a rare variety of non-Hodgkin's lymphoma of the gastrointestinal tract that usually carries a favorable course, recognized as a new entity in 2016. It is usually diagnosed at an early stage located predominantly in the second portion of the duodenum. We report the case of a 74-year-old male patient with epigastric pain in whom gastroscopy revealed white mucosal nodules that were pathologically diagnosed as grade 1-2 DFL. Staging investigations revealed secondary lesions in the spleen and at the base of the tongue together with latero-cervical adenopathy. The tumor was stage IV according to the Lugano staging system. We reviewed the recent (last five years) literature defining the importance of combination therapy in the advanced stage. The patient achieved complete remission of the disease through chemoimmunotherapy following the Rituximab-Bendamustine scheme.

Tumor Microenvironment and Microvascular Density in Follicular Lymphoma

Follicular lymphoma (FL) is a slowly progressive disease and constitutes the second most common non-Hodgkin lymphoma. Biological factors, such as the tumor microenvironment and the host response, are determinants in the outcome of FL but the experimental data about microenvironment and tumor cells in FL are variable and contradictory. In this morphometric study, we analyzed by immunohistochemistry the cellular components of the tumor microenvironment and correlated these data with the microvascular vascular density in three different grades of FL lymph node biopsies, comparing the results to healthy lymph node controls. The results indicated a significant increase in the number of CD68⁺ and CD163⁺ macrophages in all three analyzed FL grades. Tryptase⁺ mast cells resulted in an increase only in grade 1. PDL-1⁺ cells, CD4- and CD8-lymphocytes number results were reduced in FL samples. The higher number of CD34⁺ microvessels in the FL grades 1 and 2 of samples positively correlated with CD68⁺ and CD163⁺ cells, underlining the important angiogenic potential of this subset of macrophages.

Decreased expression of T-cell-associated immune markers predicts poor prognosis in patients with follicular lymphoma

We previously examined the utility of rituximab-bendamustine (RB) in patients with follicular lymphoma (FL) exhibiting less than optimal responses to 2 cycles of the R-CHOP chemotherapy regimen. The aim of this study was to identify molecular biomarkers that can predict prognosis in RB-treated patients in the context of the prospective cohort. We first analyzed the mutational status of 410 genes in diagnostic tumor specimens by target capture and Sanger sequencing. CREBBP, KMT2D, MEF2B, BCL2, EZH2, and CARD11 were recurrently mutated as reported before, however none was predictive for progression-free survival (PFS) in the RB-treated patients (n = 34). A gene expression analysis by nCounter including 800 genes associated with carcinogenesis and/or the immune response showed that expression levels of CD8⁺ T-cell markers and half of the genes regulating Th1 and Th2 responses were significantly lower in progression of disease within the 24-mo (POD24) group (n = 8) than in the no POD24 group (n = 31). Collectively, we selected 10 genes (TBX21, CXCR3, CCR4, CD8A, CD8B, GZMM, FLT3LG, CD3E, EOMES, GZMK), and generated an immune infiltration score (IIS) for predicting PFS using principal component analysis, which dichotomized the RB-treated patients into immune IIS^high (n = 19) and IIS^low (n = 20) groups. The 3-y PFS rate was significantly lower in the IIS^low group than in the IIS^high group (50.0% [95% CI: 27.1-69.2%] vs. 84.2% [95% CI: 58.7-94.6%], P = .0237). Furthermore, the IIS was correlates with absolute lymphocyte counts at diagnosis (r = 0.460, P = .00355). These results suggest that the T-cell-associated immune markers could be useful to predict prognosis in RB-treated FL patients. (UMIN:000 013 795, jRCT:051 180 181).

Clinicopathological factors and tumor microenvironment markers predicting watch-and-wait discontinuation in 82 patients with follicular lymphoma

OBJECTIVES

In this study, we aimed to determine the clinicopathological factors influencing the treatment-free period in patients with follicular lymphoma (FL) using a watch-and-wait (WW) strategy.

METHODS

We retrospectively assessed histopathological parameters of 82 patients with FL.

RESULTS

The median time from diagnosis to WW discontinuation was 62 months (range, 3-138), and median follow-up was 86 months (range, 3-183). Intermediate or high-risk Follicular Lymphoma International Prognostic Index score (P = .012), non-duodenal-type (P = .011), higher numbers of interfollicular CD4⁺ (P = .038) and intrafollicular FOXP3⁺ cells (P = .024) in the tumor microenvironment, and Ki-67 index ≥10% (P = .031) were significant adverse factors for WW discontinuation in univariate analyses.

CONCLUSION

Patients with adverse factors for WW discontinuation should be carefully observed during follow-up.

Low absolute lymphocyte count is a poor prognostic factor for untreated advanced follicular lymphoma treated with rituximab plus bendamustine: results of the prospective phase 2 CONVERT trial

The aim of this trial is to evaluate the utility of rituximab-bendamustine (R-B) for untreated advanced follicular lymphoma (FL) showing non-optimal response (nOR) to R-CHOP, and to identify clinical prognostic factors for FL patients receiving R-B. Patients who failed to achieve complete response/complete response unconfirmed (CR/CRu) [nOR-group] after 2 cycles of R-CHOP subsequently received 6 cycles of R-B. The primary endpoint was the 3-year progression-free survival (PFS) rate. Secondary endpoints included determination of prognostic factors. Fifty-six patients initially received R-CHOP, 43/56 patients (76.8%) were judged as nOR, and 33/43 patients (76.7%) completed 6 cycles of R-B. At a median follow-up of 50.6 months in the nOR-group, the 3-year PFS rate was 69.0%, and the 3-year overall survival (OS) rate was 92.7%. The most common toxicities associated with R-B were grade 3-4 lymphopenia (93.0%) and neutropenia (74.4%), both of which were manageable. A multivariate analysis including dose intensity, serum soluble interleukin-2 receptor, and FL international prognostic index-2 revealed low absolute lymphocyte count (<  869/μL) at diagnosis was an independent poor prognostic factor for both PFS and OS in the R-B-treated nOR-group. This result was further confirmed in validation cohorts including R-B-treated de novo (n = 40) and relapsed (n = 49) FL patients.