Long surviving glioblastomas (GBM) are defined as when cases have an overall survival of >5 years from the diagnosis of GBM, accounting for 5% of all GBM cases.1 It is well known that neurocognitive impairment, resulting in behavioural, emotional, and intellectual difficulties, occurs in most patients with GBM and negatively impacts quality of life (QoL) and independence in daily life. Several factors are correlated with the neurocognitive performances and QoL of these patients, including brain tumour-related epilepsy, antiepileptic drugs, antineoplastic treatments, and patient-related factors (age, comorbidity, and psychological distress).
To date, there have been few longitudinal studies on neurocognitive functions in patients with GBM;2 thus, the aim of this study was to evaluate the neurocognitive status of a cohort of 16 long surviving GBM patients. Most patients had stable disease, while three were on chemotherapy treatment. We employed the standard multidimensional health-related QoL questionnaires (European Organisation for Research and Treatment of Cancer [EORTC] QLQ-C30 and QLQ-BN20), Hospital Anxiety and Depression Scale, Controlled Oral Word Association Test, Hopkins Verbal Learning Test-Revised, and Trail Making Test in order to assess QoL and neurocognitive performances at baseline and every 6 months.
The most affected cognitive domains were the immediate and delayed recall and executive skills, resulting in word selection and verbal fluency difficulties. In this regard, a critical point is the ecological value of the neurocognitive assessment, known as the ability to measure cognitive performances in daily activities, and the implication of the cognitive impairment in the functioning of daily life. In our cohort, the executive and memory impairments did not heavily impact the independence in activities of daily life, suggesting a poor ecological value of the neurocognitive assessment. Thus, simpler, more sensitive, and ecological instruments are needed to study the relationship between QoL and cognitive performances.3
The possibility of tumour recurrence represents a psychological burden with anxiety, depression, and concerns. Moderate depressive and anxiety symptoms were reported in 36% and 17% of our patients, respectively. Particularly in our cohort, mood alterations correlated with a more negative self-perception of QoL and fatigue, which is corroborated in the literature.4 Patients with depression show a more pessimistic attitude towards testing, are more fearful of test outcomes, and have lower performance motivation, inducing poor secondary performances.5 Therefore, the performance dysfunctions do not necessarily mirror brain dysfunctions in areas hosting cognitive functions, and mood alterations may play a confounding role. Moreover, a dissociation between objective cognitive test results and self-reported cognitive function holds true, especially for long surviving GBM patients, whose judgement could be severely impaired by the tumour and multimodal treatments.6
Identifying and understanding potential clinical, biological, and lifestyle related factors of the long-term survival of GBM patients is the goal of an ongoing, large, comprehensive multicentre study7 that is led by EORTC. One of the major aims of the study is to collect QoL data, including extensive neurocognitive assessments, for a better understanding of the implications of the disease as well as the therapies in long surviving GBM patients.