Impact of surgery versus other treatment options in recurrent glioblastoma. Analysis of the Spanish Group of Neurooncology Research (GEINO) RETSINE database.
Authors: Vaz Salgado María Ángeles , Ceballos Lenza Isaac , Berron Sonia Del Barco , Gallego Rubio Oscar , Gironés Sarrió Regina , Quintanar Verduguez Maria Teresa , Sarabia Rosario , Díaz-Santos Javier , Ivars Rubio Alejandra , Fernandez Isaura , Gutierrez Toribio María , Tuñón Alvarez Maria Teresa , Cunquero Tomas Alberto Jacobo , Moya Horno Irene , Sepulveda Sánchez José Manuel , Peralta Muñoz Sergio , Alvarez-Ballesteros Pablo , De Las Peñas Bataller Ramon 
Published: June 2021

e14047 Background: Glioblastoma (GBM) is the most common brain primary tumor. Almost all patients have recurrent disease after initial treatment with surgery, radiotherapy and chemotherapy. After disease recurrence, there is no standardized treatment and reoperation is common but there is no proven benefit in randomized trials. Here we retrospectively review the Spanish national database to identify the frequency of reoperations in recurrent GBM and to analyze the impact of surgery on survival in this setting. Methods: We retrospectively reviewed relapsed GBM patients from the Spanish national database RETSINE (Registro Nacional Español de Tumores del Sistema Nervioso Central) supported by the GEINO group. Kaplan-Meier curves and log rank test were used to compare survival. Results: The number of patients with recurrent GBM analyzed was 538, 40% were women and 60% were men. The MGMT status was: methylated 30.9%, unmethylated 33.8%, unknown 35.3%. A total of 89.9% of the patients received radiotherapy and 88.7% received chemotherapy after initial surgery. The median progression-free survival until first recurrence was 7.63 months (IC95% 6.97-8.29). Median overall survival (OS) from GBM diagnosis was 11.96 months (IC95% 10.69- 23.23). At the time of the first progression, surgery was performed in 75 patients, (13.9%), 18 cases were treated with a second radiotherapy (3.3%), second line CT was administered in 268 patients (49.6%), 221 cases received only chemotherapy (40.9%), 47 cases were treated with both surgery and chemotherapy (8.7%); 28 were treated with surgery without chemotherapy (5.2%), 19 cases had a surgery procedure but we have no data about CT, 223 cases did nor receive CT nor surgery (41%). Median overall survival after relapse was 4.06 months (IC95% 3.25-4.87). For those patients without surgery, median OS after relapse was 3.1 m (IC95% 2.84-3.71) and for patients reoperated, median OS was 12.2 m (IC95% 10.8-13.52) p=0.00 Median overall survival after relapse was 1.7 months (IC95% (IC 1.31-2.08) for patients that did not had CT and 7.03 for those with CT(IC95%5.9-8.16) p=0.00 We also compared the results from different treatment options: median OS was 1.6 m (IC95% 1.11-2.08), for patients without treatment; 6.33 m (IC95% 5.34-7.32) for patients treated with chemotherapy; 12.2 m (IC95%11.05-13.34) for patients treated with surgery and CT;12.1 m(IC95% 4.64-19.55) for patients with surgery. Conclusions: Recurrent glioblastoma is a very aggressive disease. In this retrospective study, patients treated with surgery and surgery and CT could have a clinical benefit in terms of survivalin comparison with those not treated with reoperation. Randomized prospective trials are needed to clarify the role of surgery in recurrent GBM.