Challenges in glioblastoma research: focus on the tumor microenvironment.

Glioblastoma (GBM) is the most deadly type of malignant brain tumor, despite extensive molecular analyses of GBM cells. In recent years, the tumor microenvironment (TME) has been recognized as an important player and therapeutic target in GBM. However, there is a need for a full and integrated understanding of the different cellular and molecular components involved in the GBM TME and their interactions for the development of more efficient therapies. In this review, we provide a comprehensive report of the GBM TME, which assembles the contributions of physicians and translational researchers working on brain tumor pathology and therapy in France. We propose a holistic view of the subject by delineating the specific features of the GBM TME at the cellular, molecular, and therapeutic levels.

Bone sarcomas: from biology to targeted therapies.

Primary malignant bone tumours, osteosarcomas, and Ewing sarcomas are rare diseases which occur mainly in adolescents and young adults. With the current therapies, some patients remain very difficult to treat, such as tumour with poor histological response to preoperative CT (or large initial tumour volume for Ewing sarcomas not operated), patients with multiple metastases at or those who relapsed. In order to develop new therapies against these rare tumours, we need to unveil the key driving factors and molecular abnormalities behind the malignant characteristics and to broaden our understanding of the phenomena sustaining the metastatic phenotype and treatment resistance in these tumours. In this paper, starting with the biology of these tumours, we will discuss potential therapeutic targets aimed at increasing local tumour control, limiting metastatic spread, and finally improving patient survival.

Risk adapted chemotherapy for localised Ewing's sarcoma of bone: the French EW93 study.

AIM OF THE STUDY: To determine whether a risk factor adapted chemotherapy would improve the outcome of non-metastatic bone Ewing's sarcoma. METHODS: Standard risk tumours (SR, good histological response to chemotherapy or small unresected tumours) received the previous EW88 chemotherapy. Ifosfamide/etoposide (IE) were introduced after 3 courses of cyclophosphamide/doxorubicine when tumour regression was <50% or during consolidation therapy for the intermediate risk tumours (IR, intermediate histological response 5-30% residual cells or large unresected tumours >100ml). High risk tumours (HR, histological poor response >30% residual cells or clinical poor response <50% for unresectable tumours), received IE prior high dose busulfan/melphalan with stem cell rescue. RESULTS: From 1993 to 1999, 214 patients were enrolled. 5 y-EFS and OS were 60% (95% confidence interval (CI), 53-66) and 69% (95% CI, 63-75), respectively. 116 (54%), 46 (21%), 48 (22%) patients were considered as SR, IR and HR of relapse, respectively. No advantage to IE was observed in the IR group. As compared to previous study, tumour with poor histological response to induction chemotherapy seemed to benefit from the consolidation strategy including busulfan/melphalan: EFS were 45% (95% CI, 30-60) and 20% (95% CI, 7-43) for EW93 and EW88, respectively. Despite a risk-adapted strategy, histological response to chemotherapy remains the main prognostic factor in resected tumours, while initial tumour volume is the main prognostic factor for unresected tumours. CONCLUSION: These results showing a potential benefit of a consolidation strategy including busulfan/melphalan as compared to conventional chemotherapy needed confirmation by a randomised trial and were one of the bases of the ongoing EuroEwing99.