STAT3 Activation Is Associated with Interleukin-10 Expression and Survival in Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma: advances in its pathogenesis, molecular markers and targeted therapies

PURPOSE OF REVIEW

Primary central nervous system lymphoma (PCNSL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL) located in the CNS with a less favorable prognosis. Recent information addressing the disease molecular heterogeneity is paving the way for tailored treatment strategies. This article reviews current work on the pathogenesis of the disease, potential biomarkers, and treatments.

RECENT FINDINGS

Previous molecular classifications of PCNSL, built on DLBCL heterogeneity, did not properly address its intrinsic variability. Recent evidence has shown the existence of four different molecular PCNSL subtypes with associated multiomic characteristics, including prognostic relevance. Several studies have identified the tumor microenvironment (TME) as a driving prognostic factor in PCNSL. Therapy efforts continue mainly into targeting either the NF-κβ (nuclear factor kappa-light-chain enhancer of activated B cells) pathway or modulating the TME through immunomodulatory drugs (lenalidomide) or immunotherapy (antiprogrammed cell death 1/programmed cell death 1 ligand 1).

SUMMARY

Despite the increasing understanding of PCNSL pathogenesis with recent studies, future efforts are still needed to yield diagnostic biomarkers to detect either PCNSL or its molecular subtypes and hence ease routine clinical use.

The genomic and transcriptional landscape of primary central nervous system lymphoma

Primary lymphomas of the central nervous system (PCNSL) are mainly diffuse large B-cell lymphomas (DLBCLs) confined to the central nervous system (CNS). Molecular drivers of PCNSL have not been fully elucidated. Here, we profile and compare the whole-genome and transcriptome landscape of 51 CNS lymphomas (CNSL) to 39 follicular lymphoma and 36 DLBCL cases outside the CNS. We find recurrent mutations in JAK-STAT, NFkB, and B-cell receptor signaling pathways, including hallmark mutations in MYD88 L265P (67%) and CD79B (63%), and CDKN2A deletions (83%). PCNSLs exhibit significantly more focal deletions of HLA-D (6p21) locus as a potential mechanism of immune evasion. Mutational signatures correlating with DNA replication and mitosis are significantly enriched in PCNSL. TERT gene expression is significantly higher in PCNSL compared to activated B-cell (ABC)-DLBCL. Transcriptome analysis clearly distinguishes PCNSL and systemic DLBCL into distinct molecular subtypes. Epstein-Barr virus (EBV)+ CNSL cases lack recurrent mutational hotspots apart from IG and HLA-DRB loci. We show that PCNSL can be clearly distinguished from DLBCL, having distinct expression profiles, IG expression and translocation patterns, as well as specific combinations of genetic alterations.

Relapsed Primary Central Nervous System Lymphoma: Current Advances

Primary central nervous system lymphoma is an invasive malignant lymphoma confined to the central nervous system. Although patients undergoing first-line treatment can achieve complete response, most of them still relapse within two years. Relapsed lymphoma is derived from occult lymphoma cells, and B cell receptor pathway activation and immune escape are the key mechanisms for the pathogenesis of PCNSL. Most relapses are in the central nervous system, a small number of relapses are isolated systemic relapses, and clinical symptoms occur early and vary. Current treatments for relapse include high-dose methotrexate rechallenge and other regimens of chemotherapy, whole-brain radiation therapy, hematopoietic stem-cell transplantation, targeted therapy and immunotherapy, which have become promising treatments. The overall prognosis of relapsed PCNSL is very poor, although it is affected by many factors. This article summarizes the mechanisms, related factors, clinical features, follow-up, treatment and prognosis of relapsed primary central nervous system lymphoma.

MYD88 L265P mutation and interleukin-10 detection in cerebrospinal fluid are highly specific discriminating markers in patients with primary central nervous system lymphoma: results from a prospective study

Reliable biomarkers are needed to avoid diagnostic delay and its devastating effects in patients with primary central nervous system (CNS) lymphoma (PCNSL). We analysed the discriminating sensitivity and specificity of myeloid differentiation primary response (88) (MYD88) L265P mutation (mut-MYD88) and interleukin-10 (IL-10) in cerebrospinal fluid (CSF) of both patients with newly diagnosed (n = 36) and relapsed (n = 27) PCNSL and 162 controls (118 CNS disorders and 44 extra-CNS lymphomas). The concordance of MYD88 mutational status between tumour tissue and CSF sample and the source of ILs in PCNSL tissues were also investigated. Mut-MYD88 was assessed by TaqMan-based polymerase chain reaction. IL-6 and IL-10 messenger RNA (mRNA) was assessed on PCNSL biopsies using RNAscope technology. IL levels in CSF were assessed by enzyme-linked immunosorbent assay. Mut-MYD88 was detected in 15/17 (88%) PCNSL biopsies, with an 82% concordance in paired tissue-CSF samples. IL-10 mRNA was detected in lymphomatous B cells in most PCNSL; expression of IL-6 transcripts was negligible. In CSF samples, mut-MYD88 and high IL-10 levels were detected, respectively, in 72% and 88% of patients with newly diagnosed PCNSL and in 1% of controls; conversely, IL-6 showed a low discriminating sensitivity and specificity. Combined analysis of MYD88 and IL-10 exhibits a sensitivity and specificity to distinguish PCNSL of 94% and 98% respectively. Similar figures were recorded in patients with relapsed PCNSL. In conclusion, high detection rates of mut-MYD88 and IL-10 in CSF reflect, respectively, the MYD88 mutational status and synthesis of this IL in PCNSL tissue. These biomarkers exhibit a very high sensitivity and specificity in detecting PCNSL both at initial diagnosis and relapse. Implications of these findings in patients with lesions unsuitable for biopsy deserve to be investigated.

Diagnosis, prognosis and treatment of primary central nervous system lymphoma in the elderly population (Review)

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non-Hodgkin lymphoma that is unique and different from systemic diffuse large B-cell lymphomas. The median age at diagnosis of PCNSL is 65 years and its incidence is rising rapidly in the elderly population. A total of ≥20% of all patients with PCNSL are ≥80 years old. Notably, age has been identified as an independent poor prognostic factor for PCNSL. Elderly patients have an inferior prognosis to that of younger patients and are more severely affected by iatrogenic toxicity; therefore, elderly patients represent a unique and vulnerable treatment subgroup. The present review summarized the available literature to provide an improved understanding of the epidemiology, clinical characteristics, diagnosis, prognosis and management of PCNSL in the elderly population. Notably, the incidence of PCNSL in immunocompetent elderly patients, predominantly in men, is increasing. For the diagnosis of CNSL, imaging-guided stereotactic biopsy is considered the gold standard. When stereotactic biopsy is not possible or conclusive, certain biomarkers have been described that can help establish a diagnosis. PCNSL has a very poor prognosis in the elderly, even though several prognostic scoring systems exist and several prognostic markers have been reported in patients with PCNSL. Furthermore, the treatment of elderly patients remains challenging; it is unlikely that a novel agent could be used as a curative monotherapy; however, a combination of novel agents with polychemotherapy or its combination with other novel drugs may have therapeutic potential.

Clinicopathologic significance of MYD88 L265P mutation and expression of TLR4 and P-STAT3 in primary central nervous system diffuse large B-cell lymphomas

Patients with primary central nervous system lymphoma (PCNSL) have a prognosis poorer than that of systemic lymphoma patients. In patients with this condition, TLR4/STAT3 pathway alterations and the MYD88 L265P mutation may be viable targets for therapeutic intervention. The present study was, therefore, designed to identify clinicopathologic correlates of MYD88 mutations and TLR4/STAT3 pathway alterations in PCNSL. We detected TLR4 and p-STAT3 in 41.5% (22/53) and 43.4% (23/53) of PCNSL patients, respectively, while 60.4% of these patients (32/53) were found to harbor the MYD88 L265P mutation. TLR4 expression was found to be significantly associated with the presence of multiple brain lesions, while p-STAT3 expression was significantly linked to advanced age, the presence of multiple brain lesions, non-GCB histological findings, and non-CR status. The presence of the MYD88 L265P mutation was significantly linked to advanced age, the presence of multiple brain lesions, and DLBCL molecular subtype. Multivariate analyses additionally confirmed that elevated TLR4 and p-STAT3 expression levels are associated with a poorer PCNSL patient prognosis. Based on these findings, we hypothesize that signaling through the TLR4/MYD88/STAT3 pathway plays a key role in the pathogenesis of PCNSL.

Identification of Prognostic Markers in Patients with Primary Vitreoretinal Lymphoma by Clustering Analysis Using Clinical Data

(1) Purpose: Primary vitreoretinal lymphoma (PVRL) is associated with poor prognosis because most of the patients with PVRL develop central nerve system lymphoma. The prognostic biomarker of PVRL is largely unknown. Cluster analysis has been used to identify phenotypic groups within various diseases. In this study, we aimed to describe clinical features of patients with PVRL grouped by clustering analysis and to identify biomarkers for predicting survival prognosis in patients with PVRL. (2) Materials and Methods: Forty patients with PVRL were divided into two groups by clustering analysis using clinical data. Clinical features of the two groups were compared. (3) Result: Clustering analysis classified patients into groups A and B. The survival rate during the follow-up period was significantly lower in group B than in group A (p = 0.03). Serum IgG, serum IgA, vitreous IL-10 and vitreous IL-10 to IL-6 ratio were significantly different between groups A and B (p = 0.03, 0.005, 0.008 and 0.03, respectively). Receiver operating characteristic (ROC) curves generated for the four variables indicated that serum IgA was most suitable for the prediction of prognosis. Patients with serum IgA below 184 mg/dL obtained from the ROC curve had a lower three-year survival rate (p = 0.03) and more episodes of recurrence of lymphoma (3.2 times versus 1.8 times, p = 0.02) compared with patients with serum IgA above 184 mg/dL. (4) Conclusion: The survival rate was significantly different in PVRL patients classified into two groups by clustering analysis. Patients with lower serum IgA had more recurrences and poorer survival than patients with higher IgA.