Neoadjuvant multidrug chemotherapy including High-Dose Methotrexate modifies VEGF expression in Osteosarcoma: an immunohistochemical analysis

Barbara Rossi,Carlo Fabbriciani,Barone Carlo,Giovanni Schinzari,Giulio Maccauro,Michele A Rosa,Diego Signorelli,Laura Scaramuzzo

doi:10.1186/1471-2474-11-34

Abstract

BackgroundAngiogenesis plays a role in the progression of osteosarcoma, as well as in other mesenchymal tumors and carcinomas, and it is most commonly assessed by vascular endothelial growth factor (VEGF) expression or tumor CD31-positive microvessel density (MVD). Tumor VEGF expression is predictive of poor prognosis, and chemotherapy can affect the selection of angiogenic pattern. The aim of the study was to investigate the clinical and prognostic significance of VEGF and CD31 in osteosarcoma, both at diagnosis and after neoadjuvant chemotherapy, in order to identify a potential role of chemotherapy in angiogenic phenotype.MethodsA retrospective analysis was performed on 16 patients with high grade osteosarcoma. In each case archival pre-treatment biopsy tissue and post-chemotherapy tumor specimens were immunohistochemically stained against CD31 and VEGF, as markers of angiogenic proliferation both in newly diagnosed primary osteosarcoma and after multidrug chemotherapy including high-dose methotrexate (HDMTX). The correlation between clinicopathological parameters and the degree of tumor VEGF and CD31 expression was statistically assessed using the χ2 test verified with Yates' test for comparison of two groups. Significance was set at p < 0,05.ResultsExpression of VEGF was positive in 11 cases/16 of cases at diagnosis. Moreover, 8 cases/16 untreated osteosarcomas were CD31-negative, but the other 8 showed an high expression of CD31. VEGF expression in viable tumor cells after neoadjuvant chemotherapy was observed in all cases; in particular, there was an increased VEGF expression (post-chemotherapy VEGF - biopsy VEGF) in 11 cases/16. CD31 expression increased in 11 cases/16 and decreased in 3 cases after chemotherapy. The data relating to the change in staining following chemotherapy appear statistically significant for VEGF expression (p < 0,05), but not for CD31 (p > 0,05).ConclusionsEven if the study included few patients, these results confirm that VEGF and CD31 expression is affected by multidrug chemotherapy including HDMTX. The expression of angiogenic factors that increase microvessel density (MVD) can contribute to the penetration of chemotherapeutic drugs into the tumor in the adjuvant stage of treatment. So VEGF could have a paradoxical effect: it is associated with a poor outcome but it could be a potential target for anti-angiogenic therapy.

Highlights

Angiogenesis plays a role in the progression of osteosarcoma, as well as in other mesenchymal tumors and carcinomas, and it is most commonly assessed by vascular endothelial growth factor (VEGF) expression or tumor CD31-positive microvessel density (MVD)
It is well-known that angiogenesis is an early stage in the growth of carcinomas and mesenchymal tumors: VEGF expression correlates with stage, grade and prognosis of patients with gastro-enteric, lung and breast carcinomas, soft-tissue sarcomas and chondrosarcomas [12,18,19,20,22]
Several studies have examined the clinical significance of angiogenesis-related biomarkers (VEGF, CD31, CD34, etc.) in osteosarcoma, but their results are at times in conflict and few reports relate to studies with large series

Summary

Introduction

Angiogenesis plays a role in the progression of osteosarcoma, as well as in other mesenchymal tumors and carcinomas, and it is most commonly assessed by vascular endothelial growth factor (VEGF) expression or tumor CD31-positive microvessel density (MVD). Osteosarcoma is the most common malignant bone tumor in adolescents and young adults [1,2,3] Because it is a systemic disease it requires a combined treatment consisting of neoadjuvant chemotherapy, wide tumor excision, adjuvant chemotherapy and, if necessary, resection of metastases. Angiogenesis is known to be a fundamental factor in the local growth of tumors and in progression with metastases, and is most commonly assessed by measuring either the expression of vascular endothelial growth factor (VEGF) in cancer cells or tumor CD31or CD34-positive microvessel density (MVD). Cancer cells respond to an early hypoxic stage by activating signaling pathways that induce cell proliferation, the production of angiogenic factors such as VEGF and new endothelial cell formation in order to provide a new vascular supply [14,15]

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