Hypoxia-associated protein expression in primary central nervous system diffuse large B-cell lymphoma: does it predict prognosis?

Extranodal lymphoma: pathogenesis, diagnosis and treatment

Approximately 30% of lymphomas occur outside the lymph nodes, spleen, or bone marrow, and the incidence of extranodal lymphoma has been rising in the past decade. While traditional chemotherapy and radiation therapy can improve survival outcomes for certain patients, the prognosis for extranodal lymphoma patients remains unsatisfactory. Extranodal lymphomas in different anatomical sites often have distinct cellular origins, pathogenic mechanisms, and clinical manifestations, significantly influencing their diagnosis and treatment. Therefore, it is necessary to provide a comprehensive summary of the pathogenesis, diagnosis, and treatment progress of extranodal lymphoma overall and specifically for different anatomical sites. This review summarizes the current progress in the common key signaling pathways in the development of extranodal lymphomas and intervention therapy. Furthermore, it provides insights into the pathogenesis, diagnosis, and treatment strategies of common extranodal lymphomas, including gastric mucosa-associated lymphoid tissue (MALT) lymphoma, mycosis fungoides (MF), natural killer/T-cell lymphoma (nasal type, NKTCL-NT), and primary central nervous system lymphoma (PCNSL). Additionally, as PCNSL is one of the extranodal lymphomas with the worst prognosis, this review specifically summarizes prognostic indicators and discusses the challenges and opportunities related to its clinical applications. The aim of this review is to assist clinical physicians and researchers in understanding the current status of extranodal lymphomas, enabling them to make informed clinical decisions that contribute to improving patient prognosis.

Expression of hypoxia-inducible factor 1α, glucose transporter 1, and hexokinase 2 in primary central nervous system lymphoma and the correlation with the biological behaviors

BACKGROUND

It has been indicated that abnormal glucose metabolism mediated by hypoxia-inducible factor 1α (HIF-1α) played an essential role in the development of solid tumor. However, there were rare studies about the role of them in primary central nervous system lymphoma (PCNSL).

OBJECTIVE

To investigate the protein levels of HIF-1α, glucose transporter 1 (GLUT1), and hexokinase 2 (HK2) in PCNSL and whether their levels are associated with prognostic factors.

METHODS

Expression of HIF-1α, GLUT1, and HK2 in 39 tumor tissues was evaluated by immunohistochemical stainning. The correlation of the expression of HIF-1α with the protein level of GLUT1 and HK2 was investigated. In addition, the association between these protein expression levels and clinical parameters and prognosis was analyzed.

RESULTS

In the tumor specimens of PCNSL, positive stainings of HIF-1α, GLUT1, and HK2 were in 23 patients (58.97%), 25 patients (64.1%), and 26 patients (66.67%), respectively, which were associated with the expression level of lactic dehydrogenase (LDH), but not with age, gender, number of lesion, ECOG score, or deep structure. The expression of HIF-1α was positively correlated with the expression of GLUT1 (p < .01, r = .749) and HK2 (p < .01, r = .787). Univariate analysis showed that upregulated GLUT1 was unfavorable predictors of progression-free survival (PFS) in PCNSL. The results of Cox proportional hazards model showed GLUT1 was significantly associated with shorter PFS (hazard ration: 5.65; 95% confidence interval: 1.23-25.84; p = .026).

CONCLUSIONS

This study indicated that there was a hypoxic microenvironment and HIF-1α was involved in the regulation of glycolysis pathway in PCNSL. GLUT1 might be a potential marker for shorter PFS in PCNSL.

Sustain, Adapt, and Overcome-Hypoxia Associated Changes in the Progression of Lymphatic Neoplasia

Irregular perfusion and related tissue hypoxia is a common feature of solid tumors the role of which in the survival and progression cancer has been gradually recognized. Adaptation and selection mechanisms in hypoxic areas in solid tumors are regulated by Hypoxia Inducible transcriptional factor 1 (HIF1) and other hypoxia mediators and are associated with aggressive clinical behavior in a large spectrum of malignancies. Aggressive forms of lymphatic neoplasias present with solid tumor-like features, also including rapid cell growth, necrosis and angiogenesis, the clinical potential of which is still underestimated. While the role of regional hypoxia in normal B-cell maturation and malignant transformation is becoming evident, the impact of tissue hypoxia on their behavior is not well-understood. Compared to some of the common solid cancer types data for some of the key regulators, such as HIF1 and HIF2, and for their downstream effectors are available in a limited fashion. In the current review we aim to overview the physiological aspects of major hypoxia pathways during B-cell maturation and adaptation-related changes reported in lymphatic neoplasia covering important targets, such as carbonic anhydrases IX and XII (CAIX, CAXII), glucose transporter 1 (GLUT-1) and vascular endothelial growth factor (VEGF). In conclusion, experimental and clinical results direct to important but currently unexploited role of hypoxia-driven resistance mechanisms especially in aggressive forms of B-cell neoplasia.

Prognostic role of pretreatment 18F-FDG PET/CT in primary brain lymphoma

OBJECTIVE

Primary brain lymphoma is an aggressive extranodal non-Hodgkin lymphoma with poor prognosis. Many possible prognostic factors are investigated with controversial results, but possible prognostic role of 18fluorine-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) features remains unclear. Our aim was to study the metabolic behavior of brain lymphoma at 18F-FDG PET/CT and the prognostic impact of qualitative and semiquantitative PET/CT parameters.

METHODS

Between 2006 and 2018, 52 patients (26 females and 26 males; mean age: 61 years) with histologically confirmed diagnosis of brain lymphoma who underwent 18F-FDG PET/CT for staging before any treatment were included. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS) times. Cox regression models were performed to determinate the relation between qualitative and semiquantitative PET/CT features and OS and PFS.

RESULTS

Thirty-nine patients had positive 18F-FDG PET/CT showing 18F-FDG uptake (mean SUVbw of 18.2; SUVlbm of 13.9; SUVbsa of 5; MTV of 14.8; TLG of 153) at the corresponding cerebral lesion; the remaining 13 were not 18F-FDG avid. Relapse or progression of disease occurred in 22 patients with an average time of 9.7 months; death occurred in 18 patients with an average of 7.9 months. There was no difference in PFS and OS between baseline PET/CT positive and negative groups or considering SUVbw, SUVlbm, and SUVbsa. PFS and OS was significantly shorter in patients with MTV ≥ 9.8 cm³ (p = 0.037 and p = 0.022, respectively) and TLG ≥ 94 (p = 0.045 and p = 0.0430, respectively).

CONCLUSIONS

18F-FDG avidity was noted in 75% of cases. Only metabolic tumor parameters (MTV and TLG) were independently correlated with PFS and OS.

Glucose transporter-1 as an independent prognostic marker for cancer: a meta-analysis

Objective

Glucose transporter-1 (GLUT-1) as the major glucose transporter present in human cells is found overexpressed in a proportion of human malignancies. This meta-analysis is attempted to assess the prognostic significance of GLUT-1 for survival in various cancers.

Materials and Methods

We conducted an electronic search using the databases PubMed, Embase and Web of Science, from inception to Oct 20th, 2016. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated.

Results

Fourty-one studies with a total of 4794 patients were included. High GLUT-1 expression was significantly associated with poorer prognosis [overall survival: HR = 1.833 (95% CI: 1.597–2.069, P < 0.0001); disease-free survival: HR = 1.838 (95% CI: 1.264–2.673, P < 0.0001); progression-free survival: HR = 2.451 (95% CI: 1.668–3.233, P < 0.0001); disease specific survival: HR = 1.96 (95% CI: 1.05–2.871, P < 0.0001)].

Conclusions

High GLUT-1 expression may be an independent prognostic marker to predict poor survival in various types of cancers. Further clinical trials with high quality need to be conducted to confirm our conclusion.

Hyperglycemia is associated with poor survival in primary central nervous system lymphoma patients

PURPOSE

Primary central nervous system lymphoma (PCNSL) is a type of non-Hodgkin lymphoma (NHL), and it has been postulated that metabolic disorder may contribute to NHL etiology. We retrospectively investigated the prognostic significance of hyperglycemia in patients with PCNSL. We evaluated glucose transporter type 1 (GLUT1) expression by immunohistochemistry and analyzed its association with hyperglycemia and survival.

METHODS

The medical and neuroradiologic records of 50 patients with PCNSL at our institution over the past 15 years were analyzed. Patients were divided into 3 groups based on mean fasting plasma glucose (FPG) levels: normal (<110 mg/dL), prediabetes (110-125 mg/dL), and diabetes (≥126 mg/dL). We defined prediabetes and diabetes groups as hyperglycemia.

RESULTS

Forty-four percent of patients were in the prediabetes and diabetes groups. One-year survival rates were 73%, 66%, and 43% in normal, prediabetes, and diabetes groups, respectively. Univariate analysis revealed that high age, female sex, poor performance status, high mean FPG, and monotherapy were associated with shorter survival. Multivariable Cox regression analyses showed that high mean FPG and monotherapy were significant predictors of shorter survival (p = 0.036 and p = 0.000, respectively). The GLUT1 immunohistopathologic staining was performed in 34 cases, 20 of which (58%) showed variable levels of GLUT1 expression at the cell membrane and/or cytoplasm. Prediabetes and diabetes groups had a higher percentage of GLUT1-positive cells compared with the normal group (p = 0.015).

CONCLUSIONS

These findings indicate that hyperglycemia is associated with poor survival. The putative biological mechanism might involve differential GLUT1 expression between hyperglycemic and normal states in patients with PCNSL.

VEGF overexpression is a valuable prognostic factor for non-Hodgkin's lymphoma evidence from a systemic meta-analysis

Vascular endothelial growth factor (VEGF) plays a vital role in the progression of Non-Hodgkin's lymphoma (NHL). Although multiple studies have investigated the relationship between VEGF expression and prognosis of NHL, these studies have yielded conflicting results. Therefore, we performed a meta-analysis to evaluate the role of VEGF in the prognosis of NHL patients. We systematically searched eligible studies from databases and determined that there was a significant correlation between VEGF overexpression and overall survival (HR (hazard ratio) = 1.66, 95% CI: 1.25–2.22, P = 0.001). Based on subgroup analysis by study location, number of patients, the source of VEGF expression, and study design, we found that VEGF overexpression in surgically resected tissue (HR = 1.95, 95% CI: 1.41–2.69, P = 0.000), but not in serum (HR = 1.37, 95% CI: 0.96–1.95, P = 0.087), was associated with poorer prognosis. Additionally, VEGF overexpression did not correlate with performance status, LDH level, IPI score, tumor staging, B symptoms, or NHL relapse. In summary, overexpression of VEGF in lymphoma tissue represents a promising potential prognostic factor in NHL.

Relationships between VEGF protein expression and pathological characteristics of diffuse large B cell lymphoma: a meta-analysis

We carried out the current meta-analysis of relevant cohort studies in an attempt to investigate the relationships between vascular endothelial growth factor (VEGF) expression and pathological characteristics of diffuse large B cell lymphoma (DLBCL). The following electronic databases were searched for relevant articles without any language restrictions: Web of Science (1945 ~ 2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966 ~ 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), and the Chinese Biomedical Database (CBM) (1982 ~ 2013). Meta-analyses were conducted with the use of STATA software (version 12.0, Stata Corporation, College Station, TX, USA). Odds ratios (ORs) and its 95 % confidence interval (95 % CI) were calculated. Nine clinical cohort studies with a total of 789 DLBCL patients met our inclusion criteria. The meta-analysis results showed that patients with positive VEGF expression had higher international prognostic index (IPI) scores than VEGF-negative patients (OR = 5.12, 95 % CI = 2.70 ~ 9.71, P < 0.001). There was a significantly positive association between positive VEGF expression and evaluated lactate dehydrogenase (LDH) levels (OR = 2.50, 95 % CI = 1.36 ~ 4.60, P = 0.003). We also found that patients with positive B symptoms had increased level of VEGF expression (OR = 2.02, 95 % CI = 1.08 ~ 3.77, P = 0.027). The findings of our meta-analysis provide reliable evidence that VEGF expression may be strongly correlated with pathological characteristics of DLBCL.

Breaking and entering into the CNS: clues from solid tumor and nonmalignant models with relevance to hematopoietic malignancies

Various malignancies invade the CNS sanctuary site, accounting for the vast majority of CNS neoplastic foci and contributing to significant morbidity as well as mortality. The blood-brain barrier (BBB) exhibits considerable impermeability to chemotherapeutic agents, severely limiting therapeutic options available for patients developing metastatic CNS involvement, accounting for poor outcomes. The mechanisms by which malignant cells breach the highly exclusive BBB and subsequently survive in this unique anatomical site remain poorly understood, with most of the current knowledge stemming from nonmalignant and solid malignancy models. While solid and hematologic malignancies may face different challenges once within the CNS (e.g., solid tumor parenchymal metastasis compared to masses/nodules/leptomeningeal disease in hematologic malignancies), commonality exists in the process of migrating across the BBB from the circulation. Specifically considering this last point, this review aims to survey the current mechanistic knowledge regarding malignant migration across the BBB, necessarily emphasizing the better studied solid tumor and nonmalignant models with the intention of highlighting both the current knowledge gap and additional work required to effectively consider how hematopoietic malignancies breach the CNS.

Ran GTPase-activating protein 1 is a therapeutic target in diffuse large B-cell lymphoma

Lymphoma-specific biomarkers contribute to therapeutic strategies and the study of tumorigenesis. Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma. However, only 50% of patients experience long-term survival after current treatment; therefore, developing novel therapeutic strategies is warranted. Comparative proteomic analysis of two DLBCL lines with a B-lymphoblastoid cell line (LCL) showed differential expression of Ran GTPase-activating protein 1 (RanGAP1) between them, which was confirmed using immunoblotting. Immunostaining showed that the majority of DLBCLs (92%, 46/50) were RanGAP1(+), while reactive lymphoid hyperplasia (n = 12) was RanGAP1(+) predominantly in germinal centers. RanGAP1 was also highly expressed in other B-cell lymphomas (BCL, n = 180) with brisk mitotic activity (B-lymphoblastic lymphoma/leukemia: 93%, and Burkitt lymphoma: 95%) or cell-cycle dysregulation (mantle cell lymphoma: 83%, and Hodgkin's lymphoma 91%). Interestingly, serum RanGAP1 level was higher in patients with high-grade BCL (1.71 ± 2.28 ng/mL, n = 62) than in low-grade BCL (0.75 ± 2.12 ng/mL, n = 52) and healthy controls (0.55 ± 1.58 ng/mL, n = 75) (high-grade BCL vs. low-grade BCL, p = 0.002; high-grade BCL vs. control, p < 0.001, Mann-Whitney U test). In vitro, RNA interference of RanGAP1 showed no effect on LCL but enhanced DLBCL cell death (41% vs. 60%; p = 0.035) and cell-cycle arrest (G0/G1: 39% vs. 49%, G2/M: 19.0% vs. 7.5%; p = 0.030) along with decreased expression of TPX2 and Aurora kinases, the central regulators of mitotic cell division. Furthermore, ON 01910.Na (Estybon), a multikinase inhibitor induced cell death, mitotic cell arrest, and hyperphosphorylation of RanGAP1 in DLBCL cell lines but no effects in normal B and T cells. Therefore, RanGAP1 is a promising marker and therapeutic target for aggressive B-cell lymphoma, especially DLBCL.

A novel orally available inhibitor of focal adhesion signaling increases survival in a xenograft model of diffuse large B-cell lymphoma with central nervous system involvement

Central nervous system dissemination is a relatively uncommon but almost always fatal complication in diffuse large B-cell lymphoma patients. Optimal therapy for central nervous involvement in this malignancy has not been established. In this paper, we aimed to evaluate the therapeutic effect of E7123, a celecoxib derivative that inhibits focal adhesion signaling, in a novel xenograft model of diffuse large B-cell lymphoma with central nervous system involvement. Cells obtained after disaggregation of HT subcutaneous tumors (HT-SC cells) were intravenously injected in NOD/SCID mice. These mice received oral vehicle or 75 mg/kg of E7123 daily until they were euthanized for weight loss or signs of sickness. The antitumor effect of E7123 was validated in an independent experiment using a bioluminescent mouse model. Intravenously injected HT-SC cells showed higher take rate and higher central nervous system tropism (associated with increased expression of β1-integrin and p130Cas proteins) than HT cells. The oral administration of E7123 significantly increased survival time in 2 independent experiments using mice injected with unmodified or bioluminescent HT-SC cells. We have developed a new xenograft model of diffuse large B-cell lymphoma with central nervous system involvement that can be used in the pre-clinical evaluation of new drugs for this malignancy. E7123 is a new, well-tolerated and orally available therapeutic agent that merits further investigation since it may improve current management of diffuse large B-cell lymphoma patients with central nervous system involvement.

Clinicopathological implications of the expression of hypoxia-related proteins in gastric cancer

OBJECTIVES

Tumor hypoxia confers poor prognosis of a wide range of solid tumors due to increased malignancy, increased likelihood of metastasis and treatment resistance. The aim of this study was to assess the significance of the expression of HIF-1α and HIF-1α-inducible proteins in gastric cancer and their impact on prognosis.

MATERIALS AND METHODS

The expression of HIF-1α, GLUT-1, CA-9, and iNOS proteins was analyzed by immunohistochemistry in 193 gastric adenocarcinomas (GAs) and 20 normal gastric mucosa.

RESULTS

HIF-1α, GLUT-1, CA-9 and iNOS were expressed in 52.3%, 43.0%, 57.0%, and 43.0% of GAs, respectively, which are higher than the normal counterparts except for CA-9. HIF-1α expression was positively correlated with the expression of GLUT-1, CA-9 and iNOS. GLUT-1 expression was higher in the intestinal type (p = 0.012); however, iNOS expression was higher in the less-differentiated type and the diffuse type (p = 0.006, p = 0.032, respectively). The expression of HIF-1α and GLUT-1 was significantly correlated with lymph node metastasis (p = 0.009, p = 0.008, respectively), while the expression of GLUT-1 and iNOS was significantly correlated with the depth of invasion and advanced stage (p = 0.044, p = 0.004; p = 0.009, p = 0.008, respectively). Overall survival was shorter in patients with GLUT-1 expression than in those without GLUT-1 expression, which was statistically significant by univariate analysis (p = 0.042). On multivariate analysis, however, stage was determined as the only independent prognostic marker (p < 0.001).

CONCLUSIONS

Our data suggest that overexpression of HIF-1α, GLUT-1, and iNOS may play an important role in gastric cancer progression. GLUT-1 is a potential candidate for predicting patient survival.

Combined diffusion and perfusion MR imaging as biomarkers of prognosis in immunocompetent patients with primary central nervous system lymphoma

BACKGROUND AND PURPOSE

ADC derived from DWI has been shown to correlate with PFS and OS in immunocompetent patients with PCNSL. The purpose of our study was to confirm the validity of ADC measurements as a prognostic biomarker and to determine whether rCBV measurements derived from DSC perfusion MR imaging provide prognostic information.

MATERIALS AND METHODS

Pretherapy baseline DWI and DSC perfusion MR imaging in 25 patients with PCNSL was analyzed before methotrexate-based induction chemotherapy. Contrast-enhancing tumor was segmented and coregistered with ADC and rCBV maps, and mean and minimum values were measured. Patients were separated into high or low ADC groups on the basis of previously published threshold values of ADC(min) < 384 × 10(-6) mm(2)/s. High and low rCBV groups were defined on the basis of receiver operating curve analysis. High and low ADC and rCBV groups were analyzed independently and in combination. Multivariate Cox survival analysis was performed.

RESULTS

Patients with ADC(min) values < 384 × 10(-6) mm(2)/s or rCBV(mean) values < 1.43 had worse PFS and OS. The patient cohort with combined low ADC(min)-low rCBV(mean) had the worst prognosis. No other variables besides ADC and rCBV significantly affected survival.

CONCLUSIONS

Our study reinforces the validity of ADC values as a prognostic biomarker and provides the first evidence of low tumor rCBV as a novel risk factor for adverse prognosis in immunocompetent patients with PCNSL.

18F-FDG PET is an independent outcome predictor in primary central nervous system lymphoma

Primary central nervous system (CNS) lymphoma is an aggressive non-Hodgkin lymphoma with poor prognosis. We evaluated pretreatment (18)F-FDG PET as a prognostic marker in primary CNS lymphoma.

METHODS

Forty-two immunocompetent patients with newly diagnosed primary CNS lymphoma who underwent pretreatment (18)F-FDG PET were retrospectively analyzed. Baseline status and response to treatment were evaluated by MR imaging. Tumor maximum standardized uptake values were assessed by volume-of-interest analyses using an automatic isocontour definition. A 10-step semiquantitative visual rating system (metabolic imaging lymphoma aggressiveness scale, or MILAS) was used to assess primary CNS lymphoma metabolism as a marker of clinical aggressiveness. Logistic regression, log-rank testing, and multivariable Cox regression were used to investigate the association between (18)F-FDG uptake and tumor response and survival.

RESULTS

Mean maximum standardized uptake value correlated linearly with MILAS. The distribution of patients according to MILAS (0-9) was 0%, 28.6%, 23.8%, 21.4%, 11.9%, 4.8%, 7.1%, 0%, 0%, and 2.4%. There was no correlation between MILAS and response to treatment. Respective 2- and 5-y survival rates were 52% and 32% for progression-free survival (PFS) and 64% and 50% for overall survival (OS). A cutoff at MILAS 3 was a good separator for PFS (median: 54.7 mo [≤3], 3.8 mo [>3], P = 0.0272) and OS (median: not reached [≤3], 13.8 mo [>3], P = 0.131). In multivariable analyses, increasing MILAS was significantly associated with shorter PFS (hazard ratio, 1.49, P = 0.006) and OS (hazard ratio, 1.43, P = 0.018).

CONCLUSION

Increased pretreatment (18)F-FDG uptake may offer new opportunities for baseline risk evaluation in untreated primary CNS lymphoma.

Prognostic significance of hypoxia inducible factor-1α and vascular endothelial growth factor expression in patients with diffuse large B-cell lymphoma treated with rituximab

We evaluated hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression and their prognostic significance in diffuse large B-cell lymphoma (DLBCL). Expression of HIF-1α and VEGF was studied in 78 patients and results correlated with clinicopathological and prognostic data. HIF-1α and VEGF were expressed in 67% and 84% of patients, respectively, and a significant correlation was demonstrated between them (p < 0.001). Outcome was analyzed according to treatment. HIF-1α positive patients given rituximab demonstrated improved outcome, with 5-year overall survival of 72% for those receiving rituximab versus 65% for those not receiving rituximab, and 5-year progression-free survival (PFS) 76% versus 57%. No correlation was demonstrated between HIF-1α and other prognostic biomarkers including BCL6, CD10 and MUM-1. We demonstrated significantly improved PFS (p = 0.003) in patients receiving rituximab and showing BCL6 overexpression. The results confirm the significant association between HIF-1α and VEGF expression and suggest that HIF-1α expression is a favorable prognostic factor in patients with DLBCL treated with rituximab.

Current and emerging pharmacotherapies for primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) constitutes a rare group of extranodal non-Hodgkin's lymphoma (NHL) primarily of B cell origin. It occurs in both immuno-competent and immune-compromised patients. High dose m ethotrexate (HD-MTX) based chemotherapy is the standard therapy. Chemotherapy with whole brain radiation therapy (WBRT) improves response rates and survival compared with WBRT alone. However, due to the increased risk for neurotoxicity with WBRT, recent studies have focused on using chemotherapy alone. Methotrexate based multi-agent chemotherapy without WBRT is associated with similar t reatment rates and survival compared with regimens that include WBRT although controlled trials have not been performed. Because of the low incidence of this disease, it is difficult to conduct randomized controlled trials. In this article we have discussed about the past, present and emerging treatment options in patients with PCNSL.