The survival impact of significant delays between surgery and radiochemotherapy in glioblastoma patients: A retrospective analysis from a large tertiary center

Łukasz Magrowski,Elżbieta Nowicka,Oliwia Masri,Andrzej Tukiendorf,Rafał Tarnawski,Marcin Miszczyk

doi:10.1016/j.jocn.2021.05.002

Abstract

The optimal timing of adjuvant radiochemotherapy (RCT) in glioblastoma (GBM) patients remains unknown and the paradigm of ‘the sooner, the better’ has been challenged by many recent publications. In this study, we present unique data on the outcomes of patients with significant treatment delays. The study group consisted of 346 GBM patients (median age 56.8 years) who received surgical treatment (total or subtotal resection) and then underwent adjuvant concurrent RCT at one institution. The main endpoint was overall survival (OS). The Univariate and multivariate Cox Proportional-Hazard Model, log-rank test, and Kaplan-Meier method were used for the analysis. The median OS was 18.7 months and the 5-year overall survival was 8.5%. The median time interval from surgery to RCT was 9.8 weeks. The Cox regression showed that the time interval had no statistically significant impact on OS both in uni- and multivariate analysis. The explorative analysis suggested a positive trend for improved survival for patients in the 1st quartile of the time interval, especially for patients with residual disease or local recurrence prior to RCT, However, considering the 6.9 weeks median interval in the 1st quartile, this subgroup should still be regarded as 'moderate delay' compared with other literature data. The results indicate that the time interval is not a clear prognostic factor in the treatment of GBM. Prospective trials are highly warranted, as data suggest that moderate delays in the initiation of adjuvant treatment might be associated with survival benefit.

Highlights

Glioblastoma is the most common malignant brain tumour, accounting for one-fifth of primary central nervous system tumours in adults
The analysis presented in this article was initiated because of a concern that due to the overburdened healthcare in Poland and suboptimal administrative solutions, we are in a necessity for a change in order to provide better care for our glioblastoma patients
The study group had overall survival (OS) comparable to other literature data despite significant delays between surgery and radiochemotherapy, substantially longer than those considered a standard of care

Summary

Introduction

Glioblastoma is the most common malignant brain tumour, accounting for one-fifth of primary central nervous system tumours in adults. The treatment is truly comprehensive, including surgery, radiotherapy (RT), and chemotherapy (CT), yet the prognosis remains dreadful with a median survival of 15 months and no notable improvement in population statistics over the last three decades [1]. Regarded as one of the most important studies on the subject of glioblastoma, the study by. Wybrzez_ e Armii Krajowej 15, 44-102, Gliwice, Roger Stupp published in 2005 showed that the addition of temozolomide-based concurrent and adjuvant CT to RT improves the overall survival of patients [2]. The same author published the results of another randomized clinical trial on the subject of Tumor Treating Fields as an addition to temozolomidebased adjuvant treatment, which showed a statistically significant and clinically meaningful survival benefit [3]. The median survival did not exceed 14.6 and 20.5 months in the respective study groups

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