The role of surgical treatment of recurrent glioblastomas

Abstract

Introduction. With standard treatment of glioblastoma, the vast majority of cases result in relapse of the disease, for which there is no consensus on the effectiveness of repeat resection. The lack of Level 1 evidence on the efficacy of surgical removal of recurrent glioblastomas (GB) indicates that the problem has not been resolved and stimulates interest in finding ways to combat this disease. Purpose. To study the effect of surgical treatment of a recurrent tumor on the overall life expectancy and post-relapse survival time of patients with glioblastomas. Materials and methods. The analysis was performed on data from 116 patients: 43 (37.1 %) women and 73 (62.9 %) men. The mean age at the time of diagnosis (primary surgery) was 52±12 full years. Surgical interventions were performed between 1999 and 2017. The study group included 50 patients who underwent GB resection. The control group consisted of 66 patients who were not operated on for GB. To achieve group homogeneity for all studied variables, the pseudo-randomization method was used. Statistical analysis was performed using the program SPSS Statistics 26.0. Results. The median overall life expectancy after GB resection was 23.6 [95 % CI=18.1–29.1] months, in the control group — 21.0 [95 % CI=12.8–29.2] months. The fatal outcome for the patients in the study group was simultaneously influenced by two characteristics: the duration of the relapse-free period (p=0.003) and the volume of the recurrent tumor (p=0.050). For the patients in the control group, only the duration of the relapse-free period (p <0.001) was impactful. The median post-relapse survival time was higher in those patients who underwent resection of 95 % or more of the GB volume than in those without surgery: 10.33 months [95 % CI 9.67 — NA months] and 6.33 months [95 % CI 5.07–11.2 months] (p<0.05), respectively. The 2‑year survival rate in the group after resection of 95 % or more of the GB volume is more than twice as high as in the non-operated group: 38.5 % and 13.7 %, respectively. Conclusions. Maximum reduction in GB volume appears to be advisable, especially in patients with a long relapse- free period when the formation is localized in the subdominant hemisphere of the brain, without spreading to the corpus callosum. Microsurgical removal of recurrent glioblastomas is an effective method of treating patients in comparison with conservative therapy.