P13.10SURGICAL TREATMENT FOR GLIOBLASTOMA MULTIFORME: OUTCOME AND ANALYSIS OF PROGNOSTIC FACTORS ESPECIALLY ORIENTED TO THE EXTENT OF SURGICAL RESECTION

INTRODUCTION: The prognosis of Glioblastoma Multiforme (GBM) remains poor despite recent therapeutic advances. The surgical treatment of GBM (supported by functional imaging, neuronavigation and electrophysiological monitoring) remains a fundamental step. The methylation of the enzyme O6-methylguanine-DNA methyltransefrase (MGMT) seems to improve the effectiveness of alkylating agents on this tumour, but other factors can influence the survival. An evaluation of all prognostic factors is essential to individuate subgroups of patients for a better selection of different treatment modalities. Our study confirms the prognostic values of both new recognized factors (MGMT presence, IDH1, news schedule of TM2 etc.) and the well-recognized prognostic factors particularly to the extent of surgical removal with the help of new technologies and in the era where people is asking more and more a better quality of life. METHODS: We retrospectively analysed 172 operated patients (115 males and 57 females), 55 of which located in eloquent areas, between March 2008 and December 2012. For each patient age, sex, preoperative clinical evaluation (Karnofsky score, KPS), tumour location, extent of surgical removal, genetic and epigenetic profile (MGMT, IDH1,etc) and postoperative treatments were recorded. We used Kaplan Meier method for the univariate analysis and the Cox regression for the multivariate one. Surgical strategy was always planned for a total tumour resection, when allowed by the intrinsic characteristics of the tumour using the so called “extracapsular “ technique. RESULTS: Overall median survival time after surgery was 10 months. At univariate analysis the gross total removal (p 70 (p<0,0001) and radiotherapy (p<0,0001) improve survivals. Deep structures involved or multifocal lesions (p<0,0001) resulted as negative factors in term of the quod vitam prognosis, whereas lesions arising in insula, deep structures or in primary motor cortex worse the quod valitudinem prognosis (persistent deficit after three months of follow-up). Unexpectedly we noticed that the eloquent area involved doesn't influenced the extent of tumour resection. At multivariate analysis only the extent of tumour removal (p<0,0001), the postoperative KPS (p = 0,011) and the postoperative treatments undergone (p<0,0001) has been confirmed as able to influence the prognosis. CONCLUSIONS: A complete surgical removal, a good post-operative KPS and a postoperative radio-chemotherapy according to Stupp protocol were conditions for a longer survival. To obtain a complete tumour removal minimizing at the same time postoperative deficits it's mandatory to use the most complete pre-operative planning and intra-operative monitoring, using the newest functional mapping technologies, and whenever possible planning an “extracapsular” tumour resection strategy.