Celine Boucard

Association of matrix metalloproteinase 2 plasma level with response and survival in patients treated with bevacizumab for recurrent high-grade glioma

BACKGROUND A predictive marker of bevacizumab activity is an unmet medical need. We evaluated the predictive value of selected circulating prebiomarkers involved in neoangiogenesis and invasion on patient outcome in recurrent high-grade glioma treated with bevacizumab. METHODS Analyzed in plasma were a set of 11 prebiomakers of interest (vascular endothelial growth factor receptor [VEGF]; VEGF receptor 2; basic fibroblast growth factor; stromal cell derived factor 1; placenta growth factor; urokinase-type plasminogen activator; plasminogen activator inhibitor 1; matrix metalloproteinases 2, 7, and 9; and adrenomedulline), using ELISA, at baseline and 2 weeks after bevacizumab initiation in a prospective cohort of 26 patients (Cohort 1). Correlations were validated in a separate retrospective cohort (Cohort 2; n = 50) and tested in cohort patients treated with cytotoxic agents without bevacizumab (Cohort 3; n = 34). Dosages were correlated to objective response, progression-free survival (PFS), and overall survival (OS). RESULTS In Cohort 1, high MMP2 baseline level was associated with a probability of objective response of 83.3% versus 15.4% for low MMP2 level (P = .001). In multivariate analysis, baseline level of MMP2 correlated with PFS (hazard ratio, 3.92; 95% confidence interval [CI]:1.46-10.52; P = .007) and OS (hazard ratio, 4.62; 95% CI: 1.58-13.53; P = .005), as decrease of VEGF (P = .038 for PFS and P = .013 for OS) and MMP9 (P = .016 for PFS and P = .025 for OS). In Cohort 2, MMP2, but not MMP9, confirmed its predictive significance. In Cohort 3, no association was found between MMP2, MMP9, and outcome. CONCLUSION In patients with recurrent high-grade glioma treated with bevacizumab, but not with cytotoxic agent, high MMP2 plasma levels are associated with prolonged tumor control and survival. MMP2 should be tested in randomized clinical trials that evaluate bevacizumab efficacy, and its biological role reassessed.

Epidermal growth factor receptor in glioblastomas: correlation between gene copy number and protein expression

Epidermal growth factor receptor is a transmembrane receptor involved in oncogenesis, including the development of glioblastoma. We studied the prognostic significance of epidermal growth factor receptor amplification as determined by fluorescence in situ hybridization, quantitative polymerase chain reaction, and protein expression by immunohistochemistry. Ninety-nine patients exhibiting glioblastoma were included. Immunohistochemistry was performed on microarray blocks with clone 25, which recognizes both epidermal growth factor receptor wild type and vIII, and scored using a semiquantitative approach. Quantitative polymerase chain reaction and fluorescence in situ hybridization techniques were performed on frozen section: 29.3% of cases had a high epidermal growth factor receptor immunohistochemistry score (score >/=200); and of these cases, 96.5% had gene amplification by fluorescence in situ hybridization and quantitative polymerase chain reaction. Conversely, of cases with a low immunohistochemistry score, 72.9% had normal karyotype or polysomy 7 by fluorescence in situ hybridization technique; but around 25% had gene amplification by fluorescence in situ hybridization and quantitative polymerase chain reaction. In the case of protein overexpression, quantitative polymerase chain reaction and fluorescence in situ hybridization could be avoided in first intention because their positive predictive value for amplification is 97%. In multivariate analysis, there was a trend toward an association between shorter overall survival time and epidermal growth factor receptor amplification as determined by fluorescence in situ hybridization analysis. However, cases with an immunohistochemistry score less 200 require further testing by fluorescence in situ hybridization or quantitative polymerase chain reaction.

Molecular heterogeneity of glioblastomas: does location matter?

Glioblastomas in adults are highly heterogeneous tumors that can develop throughout the brain. To date no predictive-location marker has been identified. We previously derived two glioblastoma cell lines from cortical and periventricular locations and demonstrated distinct transcriptomic profiles. Based on these preliminary results, the aim of this study was to correlate glioblastoma locations with the expression of ten selected genes (VEGFC, FLT4, MET, HGF, CHI3L1, PROM1, NOTCH1, DLL3, PDGFRA, BCAN). Fifty nine patients with newly diagnosed glioblastomas were retrospectively included. Tumors were classified into cortical and periventricular locations, which were subsequently segregated according to cerebral lobes involved: cortical fronto-parietal (C-FP), cortical temporal (C-T), periventricular fronto-parietal (PV-FP), periventricular temporal (PV-T), and periventricular occipital (PV-O). Gene expression levels were determined using RT-qPCR. Compared to cortical glioblastomas, periventricular glioblastomas were characterized by a higher expression of two mesenchymal genes, VEGFC (p = 0.001) and HGF (p = 0.001). Among cortical locations, gene expressions were homogeneous. In contrast, periventricular locations exhibited distinct expression profiles. PV-T tumors were associated with higher expression of two proneural and cancer stem cell genes, NOTCH1 (p = 0.028) and PROM1 (p = 0.033) while PV-FP tumors were characterized by high expression of a mesenchymal gene, CHI3L1 (p = 0.006). Protein expression of NOTCH1 was correlated with RNA expression levels. PV-O glioblastomas were associated with lower expression of VEGFC (p = 0.032) than other periventricular locations, whereas MET overexpression remained exceptional. These data suggest a differential gene expression profile according to initial glioblastoma location.

Relationship between magnetic resonance imaging characteristics and plasmatic levels of MMP2 and MMP9 in patients with recurrent high-grade gliomas treated by Bevacizumab and Irinotecan

Matrix metalloproteases MMP2 and MMP9 are involved in cancer angiogenesis and invasion. We recently demonstrated that plasma MMP2 and MMP9 levels could both predict response to bevacizumab in patients with recurrent high-grade glioma (HGG). We examined the potential relationship between MMP2/MMP9 plasma levels and glioma imaging characteristics. In this retrospective, monocentric study, MRI before bevacizumab administration for HGG patients was independently analyzed for contrast enhancement (CE) and FLAIR sequences. Contemporary MMP2 and MMP9 plasma levels were assessed using ELISA kits. We analyzed 28 patients with a median Karnofsky Performance Status of 70 (range 50–80). A diffuse pattern was observed in 14 patients (50%). We did not observe any correlation between baseline imaging features and plasma levels of MMP2 or MMP9. We found no association between baseline MMP levels and diffuse MRI patterns. In univariate analyses, diffuse pattern, multi-focal disease, tumor diameter, surface area, and volume had no impact on outcome, while the number of lobes involved in CE and crossing of the midline by CE were associated with a worse progression-free survival (p = 0.072 and p = 0.012, respectively) and overall survival (p = 0.012 and p < 0.001, respectively). In patients with recurrent high-grade glioma treated with a bevacizumab-based regimen, our exploratory analysis of multiple MRI tumor characteristics at baseline failed to detect a relationship between imaging feature and plasma levels of MMP2 and MMP9. Our results suggests that number of lobes involved in CE and crossing of the midline by CE are associated with outcome although the potential prognostic versus predictive role of these markers warrant further investigation.

Changes in PlGF and MET-HGF expressions in paired initial and recurrent glioblastoma

Angiogenesis is one of the key features of glioblastoma (GB). However, the use of anti-angiogenic therapies directed against vascular endothelial growth factor (VEGF) is limited by primary or acquired resistance. MET/HGF and PlGF signaling are involved in potential alternative escape mechanisms to VEGF pathway. Our objective was to explore the potential changes of MET/HGF and PlGF expression, comparing initial diagnosis and recurrence after radiotherapy-temozolomide (RT/TMZ). Paired frozen tumors from both initial and recurrent surgery after radio-chemotherapy were available for 28 patients. RNA expressions of PlGF, MET, and HGF genes were analyzed by RT-qPCR. PlGF expression significantly decreased at recurrence (p = 0.021), and expression of MET showed a significant increase (p = 0.011) at recurrence. RNA expressions of MET and HGF significantly correlated both at baseline and recurrence (baseline: p = 0.005; recurrence: p = 0.019). Evolutive profile (increasing versus decreasing expression at recurrence) of MET was associated with PFS (p = 0.002) and OS (p = 0.022) at recurrence, while the evolutive profile of HGF was associated with PFS at relapse (p = 0.049). Recurrence of GB after chemo-radiation could be associated with a variation in PlGF and MET expression. These results contribute to suggest a modification of the GB angiogenic process between initial diagnosis and recurrence.

CN-18RELATIONSHIPS BETWEEN DOSE INTENSITY, TOXICITY, AND OUTCOME IN OLIGODENDROGLIAL TUMORS (OG) TREATED WITH PCV REGIMEN.

BACKGROUND: In grade II and codeleted grade III gliomas, the procarbazine-CCNU-vincristine (PCV) combination increase survival when added to radiotherapy as first line treatment, despite the important toxicity of this treatment schedule. Our objective was to analyze the tolerance, feasibility and impact of dose intensity of the PCV regimen on outcome for patients with OG. METHODS: We retrospectively reviewed all grade III OG patients receiving PCV (CCNU:110mg/m2) who were referred to our two institutions. The total dose and dose adaptation, cycle delay, dose intensity, toxicity and premature discontinuation of CCNU were analyzed. Impact of these factors on patient outcome was evaluated. RESULTS: Between 2007 and 2011, 89 patients received PCV. Only 37% completed 6 cycles, whereas 13.4% prematurely discontinued PCV because of toxicity. Cycle delay and dose reduction were observed for 62% and 70% patients, respectively. Grade 3 and 4 toxicities were observed in 38% and 8% patients, respectively. Among patients who did not progress under PCV regimen, by multivariate analysis, premature discontinuation for toxicity was significantly correlated with poor PFS (p = 0.023, Hazard ratio (HR):2.354) and OS (p = 0.021, HR:5.093). By univariate analyses, absence of CCNU dose adaptation was correlated to poor PFS (p = 0.032). For OS, pejorative factors were high total CCNU dose (p = 0.029), absence of cycle delay (p = 0.009), absence of CCNU dose adaptation (p = 0.020) and grade 3/4 toxicities (p = 0.013). High CCNU dose-intensity tended to poorly impact PFS (p = 0.053) and OS (p = 0.112). By multivariate analysis, absence of CCNU dose adaptation remained significant for PFS (p = 0.001), while OS was negatively impacted by the absence of cycle delay (p = 0.049) and grade 3/4 toxicities (p = 0.045). CONCLUSION: Despite the efficacy of the PCV regimen, significant toxicity is associated with this schedule, which appears to impact its feasibility and efficacy. The optimal PCV schedule should be redefined taking into account this finding.