Re: Doussis-Anagnostopoulouet al. Vascular endothelial growth factor (VEGF) is expressed by neoplastic Hodgkin-Reed-Sternberg cells in Hodgkin's disease.J Pathol 2002; 197: 677-683

Vascular Growth in Lymphomas: Angiogenesis and Alternative Ways

The formation of new blood vessels is a critical process for tumor growth and may be achieved through different mechanisms. Angiogenesis represents the first described and most studied mode of vessel formation, but tumors may also use alternative ways to secure blood supply and eventually acquire resistance to anti-angiogenic treatments. These non-angiogenic mechanisms have been described more recently, including intussusceptive microvascular growth (IMG), vascular co-option, and vasculogenic mimicry. Like solid tumors, angiogenic and non-angiogenic pathways in lymphomas play a fundamental role in tumor growth and progression. In view of the relevant prognostic and therapeutic implications, a comprehensive understanding of these mechanisms is of paramount importance for improving the efficacy of treatment in patients with lymphoma. In this review, we summarize the current knowledge on angiogenic and non-angiogenic mechanisms involved in the formation of new blood vessels in Hodgkin's and non-Hodgkin's lymphomas.

Whole exome sequencing in families at high risk for Hodgkin lymphoma: identification of a predisposing mutation in the KDR gene

Hodgkin lymphoma shows strong familial aggregation but no major susceptibility genes have been identified to date. The goal of this study was to identify high-penetrance variants using whole exome sequencing in 17 Hodgkin lymphoma prone families with three or more affected cases or obligate carriers (69 individuals), followed by targeted sequencing in an additional 48 smaller HL families (80 individuals). Alignment and variant calling were performed using standard methods. Dominantly segregating, rare, coding or potentially functional variants were further prioritized based on predicted deleteriousness, conservation, and potential importance in lymphoid malignancy pathways. We selected 23 genes for targeted sequencing. Only the p.A1065T variant in KDR (kinase insert domain receptor) also known as VEGFR2 (vascular endothelial growth factor receptor 2) was replicated in two independent Hodgkin lymphoma families. KDR is a type III receptor tyrosine kinase, the main mediator of vascular endothelial growth factor induced proliferation, survival, and migration. Its activity is associated with several diseases including lymphoma. Functional experiments have shown that p.A1065T, located in the activation loop, can promote constitutive autophosphorylation on tyrosine in the absence of vascular endothelial growth factor and that the kinase activity was abrogated after exposure to kinase inhibitors. A few other promising mutations were identified but appear to be "private". In conclusion, in the largest sequenced cohort of Hodgkin lymphoma families to date, we identified a causal mutation in the KDR gene. While independent validation is needed, this mutation may increase downstream tumor cell proliferation activity and might be a candidate for targeted therapy.

Micro-vessel density and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PdEGF) in classical Hodgkin lymphoma (HL)

There is little information to date regarding the role of angiogenesis in Hodgkin lymphoma (HL). The present study examines micro-vessel density and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial growth factor (PdEGF) in lymph node biopsies of patients with HL at presentation and relapse. Using immunohistochemistry, the degree of new blood vessel formation and the expression of VEGF and PdEGF was assessed in Hodgkin-rich tissue. The micro-vessel density (MVD) increased with disease progression in seven out of 11 cases. Expression of VEGF was observed in endothelial cells (EC) of some micro-vessels and also in follicular dendritic cells. The Hodgkin/Reed-Sternberg (H-RS) cells as well as the inflammatory lymphocytes were negative for VEGF. Cytoplasmic or cytoplasmic and nuclear expression of PdEGF by the H-RS cells was observed in five of the 11 presentation cases. The expression of PdEGF increased with disease progression in seven cases. In conclusion, Hodgkin tissue shows prominent vascularization. The increased MVD and PdEGF expression with disease progression merits further investigation.

Plasma heparanase as a significant marker of treatment response in children with Hodgkin lymphoma: pilot study

INTRODUCTION

The aim of this pilot study was to determine heparanase plasma levels (HP) at diagnosis and at restaging in children diagnosed with Hodgkin lymphoma and to investigate whether this parameter provides prognostic information for response to treatment after induction therapy.

PATIENTS AND METHODS

HP levels of 19 pediatric patients (mean age: 10.3 years (y) (range, 4-18 y), 9 girls, 10 boys) with Hodgkin lymphoma were assayed at diagnosis and at restaging. HP levels were determined using an ELISA anti-human heparanase immunoassay kit. According to diagnosis, CAT scan and/or FDG/ PET-CT fusion were performed to assess response to treatment after 2-3 courses of chemotherapy. Two patients received VAMP protocol (1 stage IA, 1 stage IIA), 1 received AV-PC (nonbulky stage IIA), 4 received COPP/ABV (3 stage IIA bulky, 1 stage IIIA nonbulky), 4 received ABVE-PC (2 stage IIB, 1 stage IIA bulky, 1 stage IIIA bulky), 2 received ABVD (1 stage IIA bulky, 1 stage IIIA), and 6 received escalated BEACOPP (1 stage IIIB, 3 stage IVA, 2 stage IVB).

RESULTS

Changes in HP levels were found to correlate with response to treatment for most of the children. At diagnosis, average HP level was 1019 pg/mL (range, 141-5733 pg/mL), decreasing at restaging to 588 pg/mL (range, 62-3267 pg/mL) (p = .034). At diagnosis, the average HP of the 16 patients in CR or VGPR was 1104 pg/mL; it had decreased at restaging to 586 pg/mL (p = .032). At diagnosis, the average HP level for the 3 patients with TP or PR was 1704 pg/mL; it had increased to 1938 pg/mL at restaging (p = .166). Due to the small number of patients, no correlation was observed between HP levels at diagnosis, staging, or any other clinical prognostic factor.

CONCLUSIONS

Changes in plasma HP levels correlated with response to treatment for children diagnosed with Hodgkin lymphoma. This provides a rationale for exploring clinical interest in plasma heparanase measurements of a larger group, using the test for clinical trials of antiangiogenic therapies.

Elevated Vascular Endothelial Growth Factor Pretreatment Levels Are Correlated with the Tumor Burden in Hodgkin Lymphoma and Continue to Be Elevated in Prolonged Complete Remission

BACKGROUND

Vascular endothelial growth factor (VEGF) has been described as an essential cytokine in the regulation of angiogenesis. Its elevation in peripheral blood or bone marrow has been associated with an unfavorable outcome in different hematologic neoplasms. Hodgkin lymphoma represents approximately one fifth of all lymphomas, and the roles of angiogenesis and VEGF in Hodgkin lymphoma have not been well defined at present.

PATIENTS AND METHODS

Vascular endothelial growth factor serum levels were determined by enzyme-linked immunosorbent assay in 54 newly diagnosed patients, 26 patients in prolonged complete remission (CR), and 54 healthy controls. Vascular endothelial growth factor levels were compared among the different populations and correlated with prognostic factors and disease evolution.

RESULTS

Newly diagnosed patients showed an increase in VEGF level compared with the CR subgroup (549 pg/mL vs. 327.5 pg/mL; P = 0.023) and with healthy controls (549 pg/mL vs. 140 pg/mL; P < 0.001). Patients in CR also showed an elevated VEGF with respect to healthy controls (327.5 pg/mL vs. 140 pg/mL; P = 0.01). Elevated VEGF was also statistically correlated with newly diagnosed patients with a greater tumor burden (594.5 pg/mL vs. 391 pg/mL; P = 0.009), with > or = 4 involved areas (608 pg/mL vs. 507 pg/mL; P = 0.036), and with an Eastern Cooperative Oncology Group performance status of > or = 1 (812 pg/mL vs. 447pg/mL; P = 0.005). Vascular endothelial growth factor was also elevated in advanced-stage disease, in patients with B symptoms, and poor-risk groups, but none of them became statistically significant.

CONCLUSION

Pathologic angiogenesis is an activated pathway in Hodgkin lymphoma and participates in Hodgkin lymphoma progression. This has been shown by an elevated VEGF level in patients: before first treatment, with greater tumor burden, and with a higher number of involved areas. Furthermore, VEGF continues to be elevated in patients with Hodgkin lymphoma after prolonged CR.

Serum VEGF as a significant marker of treatment response in hodgkin lymphoma

This pilot study aimed at determining serum VEGF levels (S-VEGF) at diagnosis and at restaging in children with Hodgkin lymphoma, and investigating whether this parameter provides prognostic information for remission after 2 courses of chemotherapy. PET-CT fusion was performed to assess response to treatment. Changes in S-VEGF levels were found to correlate with response to treatment for most of the children. This provides a rationale for exploring clinical interest in S-VEGF measurements in a larger group of children with Hodgkin lymphoma, and using the test for clinical trials of anti-angiogenic therapies.

Angiogenesis in Hodgkin's lymphoma: a morphometric approach in 286 patients with prognostic implications

The significance of angiogenesis in Hodgkin's lymphoma (HL) is not well defined. The aim of this study was to evaluate various morphometric characteristics of microvessels in lymph node sections of 286 patients with HL at diagnosis and investigate their relationship with clinicopathologic parameters and prognosis. Microvessel density (MVD), total vascular area (TVA) and several size- and shape-related microvascular parameters were quantitated--after anti-CD34 immunohistochemical staining--in the region of most intense vascularization, using image analysis. An increase in microvessel caliber parameters (area, perimeter, major and minor axis length) and a decrease in MVD were noted with increasing stage. An inverse relationship was recorded between MVD and the number of involved sites (NIS) and LDH. In univariate analysis, overall disease-specific survival was adversely affected by MVD and TVA, whereas inferior failure-free survival (FFS) was associated with the presence of more flattened vessel sections. Multivariate analysis disclosed that the extent of angiogenesis (MVD/TVA), age and the NIS independently affected overall survival. Accordingly, FFS was independently linked to the shape of microvessels and albumin levels or the NIS. In conclusion, our data support the view that angiogenesis in HL provides independent prognostic information, requiring the concomitant evaluation of quantitative and qualitative aspects of microvascular network.