Optimal managements of elderly patients with glioblastoma

Clinical Predictors of Overall Survival in Very Elderly Patients With Glioblastoma: A National Cancer Database Multivariable Analysis

BACKGROUND AND OBJECTIVES

Surgery for the very elderly is a progressively important paradigm as life expectancy continues to rise. Patients with glioblastoma multiforme often undergo surgery, radiotherapy (RT), and chemotherapy (CT) to prolong overall survival (OS). However, the efficacy of these treatment modalities in patients aged 80 years and older has yet to be fully assessed in the literature.

METHODS

The National Cancer Database was used to retrospectively identify patients aged 65 years and older with glioblastoma multiforme (1989-2016). All available patient demographic characteristics, disease characteristics, and clinical outcomes were collected. To study OS, bivariable survival models were created using Kaplan-Meier estimates. A Cox proportional-hazards model was used for final adjusted analyses.

RESULTS

A total of 578 very elderly patients (aged 80 years and older) and 2836 elderly patients (aged 65-79 years) were identified. Compared with elderly patients, very elderly patients were more likely to have Medicare (odds ratio [OR] 1.899 [95% CI: 1.417-2.544], P < .001) while less likely to have private insurance status (OR 0.544 [95% CI: 0.401-0.739], P < .001). In addition, very elderly patients were more likely to travel the least distance for treatment and have multiple tumors (P < .001). When controlling for demographic and disease characteristics, very elderly patients were less likely to receive gross total resection (GTR) (OR 0.822 [95% CI: 0.681-0.991], P < .041), RT (OR 0.385 [95% CI: 0.319-0.466], P < .001), or postoperative CT (OR 0.298 [95% CI: 0.219-0.359], P < .001) relative to elderly counterparts. Within very elderly patients, GTR, RT, and CT all independently and significantly predicted improved OS (P < .001 for all). These predictive models were deployed in an online calculator (https://spine.shinyapps.io/GBM_elderly).

CONCLUSION

Very elderly patients are less likely to receive GTR, RT, or CT when compared with elderly counterparts despite use of these therapies conferring improved OS. Selected very elderly patients may benefit from more aggressive attempts at surgical and adjuvant treatment.

Diagnostic and Prognostic Value of Circulating DNA Fragments in Glioblastoma Multiforme Patients

Novel blood-circulating molecules, as potential biomarkers for glioblastoma multiforme (GBM) diagnosis and monitoring, are attracting particular attention due to limitations of imaging modalities and invasive tissue biopsy procedures. This study aims to assess the diagnostic and prognostic values of circulating cell-free DNA (cfDNA) in relation to inflammatory status in GBM patients and to determine the concentration and average size of DNA fragments typical of tumour-derived DNA fractions. Preoperative plasma samples from 40 patients (GBM 65.0 ± 11.3 years) and 40 healthy controls (HC 70.4 ± 5.4 years) were compared. The cfDNA concentrations and lengths were measured using the electrophoresis platform, and inflammatory indices (NLR, PLR, LMR, and SII) were calculated from complete blood cell analysis. More fragmented cfDNA and 4-fold higher 50-700 bp cfDNA concentrations were detected in GBM patients than in healthy controls. The average cfDNA size in the GBM group was significantly longer (median 336 bp) than in the HC group (median 271 bp). Optimal threshold values were 1265 pg/μL for 50-700 bp cfDNA (AUC = 0.857) and 290 bp for average cfDNA size (AUC = 0.814). A Kaplan-Meier survival curves analysis also demonstrated a higher mortality risk in the GBM group with a cut-off >303 bp cfDNA. This study is the first to have revealed glioblastoma association with high levels of cfDNA > 1000 pg/μL of 50-700 bp in length, which can be aggravated by immunoinflammatory reactivity.