P17.14.B Strategy of the recurrent Glioblastoma treatment. Three neuro-oncology centers study

Abstract

Abstract Background The prognosis for patients with Glioblastoma (GBM) remains dismal. The most aggressive multimodal therapy (maximally radical and safe tumor resection, followed by the Stupp protocol oncotherapy) has yielded the best treatment outcomes. Notwithstanding the slowly prolonged patient′s overall survival, this tumor inevitable recurs. An optimal therapy of the recurrent GBM is still a controversial theme.The aim of our study is to evaluate our treatment strategy of recurrent GBM. Material and Methods For this study, we retrospectively selected a group of resected recurrent GBM patients in a period from June 1, 2009 to December 31, 2019, which were treated in tree Czech neuro-oncologic centers. All patients underwent early post-surgical MRI (within 72 h) to determine resection radicality. Following resection, patients received periodic checkups with MRI every 3 months until death. Patients with psedoprogession were excluded. Information about all surgeries, oncotherapies, patient clinical condition, MRI, PET/CT, and results of histological, immunohistochemical, molecular genetic, and cytogenetic investigations was gathered.We consider surgery for recurrent GBM in case, if: 1.The tumor volume increasing > 20-30% or tumor rediscovery after radiologic disappearing. 2.Clinic condition - Karnofsky score (KS) ≥ 70% and Performance status (PS) WHO ≤ gr. 2. 3.Localized tumor, without multilfocality. 4.Assumed the least tumor volume reduction > 80%. Results We gathered 122 patients with recurrent GBM, 98,9% of tumors was determined as wild-type, age median was 53,36 years. All patients underwent Stupp protocol oncotherapy after prime surgery. Median of OS from prime surgery was 21 months (15.8, 29.6). The best results proved a surgery of GBM recurrency proceeding more than 6 months after diagnosis. OS2 (from redo up to the death) was 7.4 months (6.41, 11.3). 43.3% of patients recalled temozolomide chemotherapy. We confirmed positive link between OS and resection radicality, negative relations between OS and a postoperative neurologic deficits. Only limited relation was presented between OS and repeated oncotherapy. Relation to the further histologic, imunohistochemic, cytogenetic and molecular markers will be discussed. Conclusion Due to the common unfavorable outcomes of GBM therapy, out of despair, we often decided for repeated surgery. The aim of our study was avoid ineffective surgical overtreatment. The best results of surgery yield right selected recurrent GBMs. Surgery of GBM regrown during initial oncotherapy (6 months after prime surgery) presented unsatisfactory effects. Positive effect of the surgical radicality and clinic status were confirmed. Again, necessity of second-line oncotherapy has been emerged. Supported by Ministry of Health of the Czech Republic, grant nr. NV19- 04-00281 and grant nr. NU21-03-00195