Cognitive function after concurrent temozolomide-based chemoradiation therapy in low-grade gliomas

Multidisciplinary Management of Isocitrate Dehydrogenase-Mutated Gliomas in a Contemporary Molecularly Defined Era

Mutations in isocitrate dehydrogenase (IDH) genes, an early step in the ontogeny of lower-grade gliomas, induce global epigenetic changes characterized by a hypermethylation phenotype and are critical to tumor classification, treatment decision making, and estimation of patient prognosis. The introduction of IDH inhibitors to block the oncogenic neomorphic function of the mutated protein has resulted in new therapeutic options for these patients. To appreciate the implications of these recent IDH inhibitor results, it is important to juxtapose historical outcomes with chemoradiotherapy. Herein, we rationally evaluate recent IDH inhibitor data within historical precedents to guide contemporary decisions regarding the role of observation, maximal safe resection, adjuvant therapies, and the import of patient and tumor variables. The biological underpinnings of the IDH pathway and the mechanisms, impact, and limitations of IDH inhibitors, the actual magnitude of tumor regression and patient benefit, and emergence of resistance pathways are presented to guide future trial development. Management in the current, molecularly defined era will require careful patient selection and risk factor assessment, followed by an open dialog about the results of studies such as INDIGO, as well as mature data from legacy trials, and a discussion about risk-versus-benefit for the choice of treatment, with multidisciplinary decision making as an absolute prerequisite.

Neuropsychological functioning during chemotherapy with temozolomide in high-grade glioma patients: a retrospective single centre study

PURPOSE

starting from a lack of precise and coherent data in literature, aim of this work is to retrospectively study the influence of chemotherapy with Temozolomide (TMZ) on a wide series of neuropsychological functions in a population of adult high-grade glioma patients.

METHODS

an extensive neuropsychological battery was administered pre-operatively (T0) and after 6 (T1) and 12 months (T2) from surgery. After full recovery from surgery, TMZ was delivered concomitant to radiotherapy and, subsequently, adjuvantly for 5-day cycles per month. Parametric and non-parametric analyses were conducted to verify the influence of several aspects of chemotherapy on the adjusted scores of each cognitive test at the two post-operative follow-ups.

RESULTS

Sixty-one patients were included at T0; patients with a lower adjuvant TMZ dosage reported a better performance at the visual attention test at T1, and at the deductive reasoning test at T2. Undergoing more than 8 cycles of adjuvant therapy was slightly associated with a better performance at the long-term verbal memory tasks at T2. No other associations were found with the other cognitive tests and autonomy scales administered.

CONCLUSIONS

TMZ proved to be a secure treatment with no negative side effects on cognition and on level of daily autonomy, even at the highest dosage used. This is a positive finding which enables clinicians to reassure patients about the absence of significant negative effects of TMZ on their daily life functioning. In this view, eventual cognitive changes during treatment might not be attributed to chemotherapy but to other events such as tumour relapse.

Long-term neurocognitive function and quality of life after multimodal therapy in adult glioma patients: a prospective long-term follow-up

PURPOSE

Multimodal therapies have significantly improved prognosis in glioma. However, in particular radiotherapy may induce long-term neurotoxicity compromising patients' neurocognition and quality of life. The present prospective multicenter study aimed to evaluate associations of multimodal treatment with neurocognition with a particular focus on hippocampal irradiation.

METHODS

Seventy-one glioma patients (WHO grade 1-4) were serially evaluated with neurocognitive testing and quality of life questionnaires. Prior to (baseline) and following further treatment (median 7.1 years [range 4.6-11.0] after baseline) a standardized computerized neurocognitive test battery (NeuroCog FX) was applied to gauge psychomotor speed and inhibition, verbal short-term memory, working memory, verbal and non-verbal memory as well as verbal fluency. Mean ipsilateral hippocampal radiation dose was determined in a subgroup of 27 patients who received radiotherapy according to radiotherapy plans to evaluate its association with neurocognition.

RESULTS

Between baseline and follow-up mean performance in none of the cognitive domains significantly declined in any treatment modality (radiotherapy, chemotherapy, combined radio-chemotherapy, watchful-waiting), except for selective attention in patients receiving chemotherapy alone. Apart from one subtest (inhibition), mean ipsilateral hippocampal radiation dose > 50 Gy (Dmean) as compared to < 10 Gy showed no associations with long-term cognitive functioning. However, patients with Dmean < 10 Gy showed stable or improved performance in all cognitive domains, while patients with > 50 Gy numerically deteriorated in 4/8 domains.

CONCLUSIONS

Multimodal glioma therapy seems to affect neurocognition less than generally assumed. Even patients with unilateral hippocampal irradiation with > 50 Gy showed no profound cognitive decline in this series.