BACKGROUND:

In 2016 WHO reclassified diffuse gliomas, incorporating new entities defined by histological and molecular features, such as IDH-wildtype and IDH-mutant, hoping to improve patient outcome predictions and guide individualized treatment

OBJECTIVES:

To assess GBM patient’s performance status and QoL by IDH classification.

METHODS:

Cross-sectional data were gathered using Adelphi’s Disease-Specific Programme in Canada, France, Germany, Italy, Spain and the UK (May - Sept 2016). Physicians provided patient level data on 1,747 GBM patients; 420 of those patients completed a questionnaire containing the 3L-EQ-5D and EORTC Quality of Life Questionnaire (C30 and GBM-specific BN20). Summary statistics are reported, differences assessed using pairwise t-tests and chi-square analysis.

RESULTS:

IDH status of 682 (39%) patients was provided, 31% confirmed IDH-mutant. Performance status, assessed using ECOG, showed IDH-wildtype patients as significantly more disabled than IDH-mutant at diagnosis (p<0.01) and time of reporting (p=0.01). Mean life expectancy at diagnosis (weeks) for IDH-wildtype patients was 62.6 vs. 78.1 for IDH-mutant (p<0.01); medians show a similar trend (52.0 and 65.0 respectively).

Physician subjective classification of patient GBM status showed significant differences in the proportion of patients considered ‘responding to treatment’ (IDH-wildtype 26%, IDH-mutant 35%, p<0.01) and stable (IDH-wildtype 50%, IDH-mutant 41%, p=0.02). No significant difference was noted in patients classified as progressing.

PRO data were provided from 26 IDH-mutant and 109 IDH-wildtype patients. QoL was poor, indicated by an overall mean EQ-5D index score of 0.54 with no significant difference noted by IDH status. Similarly no significant difference was noted by IDH status for the EORTC Global health status score (overall mean 44.5).

CONCLUSIONS:

With limited existing data, our data demonstrated IDH-wildtype patients were likely to have poorer performance status, shorter life expectancy and not be considered as responsive to treatment as IDH-mutant patients reinforcing the decision to reclassify GBM entities to guide patient management strategies.