Low Grade Gliomas in Eloquent Locations – Implications for Surgical Strategy, Survival and Long Term Quality of Life

Asgeir S Jakola,Ole Solheim,Sigurd Lindal,Roar Kloster,Geirmund Unsgård,Sverre H Torp,Kristin S Myrmel,Keith L Black

doi:10.1371/journal.pone.0051450

Abstract

BackgroundSurgical management of suspected LGG remains controversial. A key factor when deciding a surgical strategy is often the tumors’ perceived relationship to eloquent brain regionsObjectiveTo study the association between tumor location, survival and long-term health related quality of life (HRQL) in patients with supratentorial low-grade gliomas (LGG).MethodsAdults (≥18 years) operated due to newly diagnosed LGG from 1998 through 2009 included from two Norwegian university hospitals. After review of initial histopathology, 153 adults with supratentorial WHO grade II LGG were included in the study. Tumors’ anatomical location and the relationship to eloquent regions were graded. Survival analysis was adjusted for known prognostic factors and the initial surgical procedure (biopsy or resection). In long-term survivors, HRQL was assessed with disease specific questionnaires (EORTC QLQ-C30 and BN20) as well as a generic questionnaire (EuroQol 5D).ResultsThere was a significant association between eloquence and survival (log-rank, p<0.001). The estimated 5-year survival was 77% in non-eloquent tumors, 71% in intermediate located tumors and 54% in eloquent tumors. In the adjusted analysis the hazard ratio of increasing eloquence was 1.5 (95% CI 1.1–2.0, p = 0.022). There were no differences in HRQL between patients with eloquent and non-eloquent tumors. The most frequent self-reported symptoms were related to fatigue, cognition, and future uncertainty.ConclusionEloquently located LGGs are associated with impaired survival compared to non-eloquently located LGG, but in long-term survivors HRQL is similar. Although causal inference from observational data should be done with caution, the findings illuminate the delicate balance in surgical decision making in LGGs, and add support to the probable survival benefits of aggressive surgical strategies, perhaps also in eloquent locations.

Highlights

The clinical course for patients with diffuse infiltrating lowgrade gliomas (LGG) is often unpredictable
Eloquently located LGGs are associated with impaired survival compared to non-eloquently located LGG, but in long-term survivors health related quality of life (HRQL) is similar
Causal inference from observational data should be done with caution, the findings illuminate the delicate balance in surgical decision making in LGGs, and add support to the probable survival benefits of aggressive surgical strategies, perhaps in eloquent locations

Summary

Introduction

The clinical course for patients with diffuse infiltrating lowgrade gliomas (LGG) is often unpredictable. In such WHO grade II gliomas, negative prognostic factors for survival are advanced age, large tumor size, midline involvement, the presence of neurologic deficits and astrocytoma histopathology [1]. A key factor when deciding on the surgical strategy is often the tumors’ perceived relationship to so-called eloquent brain regions, meaning involvement of sensorimotor regions, language cortices, basal ganglia and/or larger white matter tracts. Despite the key importance for clinical decision making, the association between lesion eloquence for survival and long-term HRQL has not been much explored in LGGs. Surgical management of suspected LGG remains controversial. A key factor when deciding a surgical strategy is often the tumors’ perceived relationship to eloquent brain regions

Methods

Discussion

Conclusion