Recursive partitioning analysis of prognostic factors for glioblastoma patients aged 70 years or older

Abstract

Background The most used prognostic scheme for malignant gliomas only included patients between ages 18 to 70 years. The purpose of this study was to develop a prognostic model for patients ≥70 years of age with newly diagnosed glioblastoma. Methods Four hundred and thirty-seven patients ≥70 years of age with newly diagnosed glioblastoma, pooled from two tertiary academic institutions, were identified for recursive partitioning analysis (RPA). A resulting prognostic model, based on the final pruned RPA tree, was validated using two hundred and sixty-five glioblastoma patients ≥70 years of age from a dataset independently compiled by a French consortium. Results RPA produced nine terminal nodes, which were pruned to four prognostic subgroups with markedly different median survivals: I – patients <75.5 years of age who underwent surgical resection (9.3 mos); II – patients ≥75.5 years of age who underwent surgical resection (6.4 mos); III – patients with KPS of 70–100 who underwent biopsy only (4.6 mos); and IV – patients with KPS <70 who underwent biopsy only (2.3 mos). Application of this prognostic model to the French cohort also resulted in significantly different (P<0.0001) median survivals for subgroups I (8.5 mos), II (7.7 mos), III (4.3 mos), and IV (3.1 mos). Conclusion This model divides elderly glioblastoma patients into prognostic subgroups that can be easily implemented in both the patient care and the clinical trial settings. This purely clinical prognostic model serves as a backbone for the future incorporation of the increasing number of potential molecular prognostic markers.

Glioblastoma multiforme in the very elderly

“…Recent studies assessing prognosis in elderly glioblastoma patients have shown that regardless of age, there is a survival benefit of surgical resection over biopsy alone [17]. Buachet et al [13] also stated what has been shown in our results that resection is superior to biopsy, and that radiotherapy and chemotherapy have reasonable tolerance in the elderly, with an improvement in survival outcomes.…”

Current status and perspectives of interventional clinical trials for glioblastoma – analysis of ClinicalTrials.gov

“…For elderly patients hypofractionated radiotherapy results in only a small benefit compared to the best supportive care [30], with the most important prognostic factor being age and the performance status [31]. …”

A Surveillance, Epidemiology and End Results-Medicare data analysis of elderly patients with glioblastoma multiforme: Treatment patterns, outcomes and cost

“…By comparison, in the Nordic trial, 67% of patients aged ≥70 years had undergone complete or partial resection and in the German NOA-08 trial, 58% of the patients treated with TMZ had undergone complete or partial resection. The patients in these trials also had good overall good performance status, with a median Karnofsky score of 80, and high performance scores are also known to be a treatment-independent positive prognostic factor in brain tumor patients (20). Although our analysis could not include patient functional status, a common reason for treating elderly GBM patients with abbreviated therapies is poor function.…”