Intraoperative opioids and disease-free survival in glioblastoma multiforme

Abstract

Introduction: Glioblastoma multiforme (GBM) is a primary tumor of the Central Nervous System (CNS). It is one of the most aggressive tumors that can affect humans, with no cure so far and an extremely inverse prognosis, with an average survival ranging from 7 to 15 months. Recently, the role of opioids, either in stopping or stimulating tumor progression, has been demonstrated for both sides. The main objective of this study was to investigate the influence of intraoperative opioid use on the overall and disease-free survival of these patients. Methods: This observational and retrospective study analyzed the medical records of 133 patients who underwent 167 surgical procedures for resection of Glioblastoma Multiforme. Inclusion and exclusion criteria were as follows: patients older than 18 years of age, of both sexes, and who had confirmed GBM. Patients who died in the postoperative period from causes unrelated to the underlying disease were excluded, as were those who did not have specific data on the medications used in the perioperative period in their records. The following outcomes were analyzed: age, preoperative and postoperative Karnofsky scale (KPS), duration of the surgical procedure, opioid doses, overall survival, disease-free survival, sex, and race. To verify the existence of a correlation between quantitative variables, the Spearman Test was applied; for categorical (qualitative) variables, the Chi-square Test was used. The Kruskal–Wallis test was used to evaluate the variance in means between groups. In addition, the log-rank test was used to evaluate survival between the groups. The significance level adopted for all tests was 5% (p≤0.05). Results: Analysis of the correlation between total opioid dosage and the investigated variables showed that surgical duration and age at surgery were significantly correlated with total opioid dosage. There was no correlation between total opioid dosage and the overall and disease-free survival times of patients. Conclusion: This study suggests that there is no relationship between the intraoperative opioid dose and overall and disease-free survival in patients undergoing surgical treatment for Glioblastoma Multiforme.