Primary or secondary dissemination develops in 5–10 % 1).
Low-grade gliomas are infiltrative tumors which progressively invade the brain tissue by migrating along the subcortical white matter tracts. Contrary to the indolent characteristics claimed by classical literature, there is a constant growth pattern of these tumors before and after surgery in cases of incomplete resection 2).
Patients diagnosed with a low-grade glioma are 17 times as likely to die as matched patients in the general population 3).
The age-standardized 10-year relative survival rate was 47% 4).
Tumor histology, size and IDH-mutation status are important predictors for prolonged overall survival in patients with LGG and may provide a reliable tool for standardizing future treatment strategies 7).
Reports on long-term health related quality of life (HRQL) after surgery for World Health Organization grade II diffuse low-grade gliomas (LGG) are rare.
In two hospital cohorts with different surgical strategies. Biopsy and watchful waiting was favored in one hospital, while early resections guided with three-dimensional (3D) ultrasound was favored in the other. With a population-based approach 153 patients with histologically verified LGG treated from 1998-2009 were included. Patients still alive were contacted for HRQL assessment (n=91) using generic (EQ-5D; EuroQol Group, Rotterdam, The Netherlands) and disease specific (EORTC QLQ-C30 and BN20; EORTC Quality of Life Department, Brussels, Belgium) questionnaires. Results on HRQL were available in 79 patients (87%), 25 from the hospital that favored biopsy and 54 from the hospital that favored early resection. Among living patients there was no difference in EQ-5D index scores (p=0.426). When imputing scores defined as death (zero) in patients dead at follow-up, a clinically relevant difference in EQ-5D score was observed in favor of early resections (p=0.022, mean difference 0.16, 95% confidence interval 0.02-0.29). In EORTC questionnaires pain, depression and concern about disruption in family life were more common with a strategy of initial biopsy only (p=0.043, p=0.032 and p=0.045 respectively).
Although HRQOL remains mostly preserved in the majority of patients with LGG, a subset of patients experience detectable decline on one or more HRQOL scales despite long-term stable disease. For this subgroup, further research is recommended to better aid patients in dealing with the consequences of LGG 8).
In long-term survivors an aggressive surgical approach using intraoperative 3D ultrasound image guidance in LGG does not lower HRQL compared to a more conservative surgical approach. This finding further weakens a possible role for watchful waiting in LGG 9).
Many patients with low-grade glioma experience cognitive dysfunction. However, there is no consensus on how to assess cognitive functioning in these patients 10).
For 22 patients with newly diagnosed LGG who underwent baseline neuropsychological evaluation and magnetic resonance imaging before awake surgery resection with mapping. Twelve of the 22 patients returned for postoperative evaluation approximately 7 months after surgery.
At baseline, 92% of patients/caregivers reported changes in cognition or mood. Neurological examinations and Montreal Cognitive Assessment Scales were largely normal; however, on many tests of memory and language, nearly half of individuals showed deficits. After surgery, 45% had no deficits on neurological examination, whereas 55% had only transient or mild difficulties. Follow-up neuropsychological testing found most performances stable to improved, particularly in language, although some patients showed declines on memory tasks.
Most LGG patients in this series presented with normal neurological examinations and cognitive screening, but showed subjective cognitive and mood concerns and cognitive decline on neuropsychological testing, suggesting the importance of comprehensive evaluation. After awake mapping, language tended to be preserved, but memory demonstrated decline in some patients. These results highlight the importance of establishing a cognitive baseline before surgical resection and further suggest that awake mapping techniques provide reasonable language outcomes in individuals with LGG in eloquent regions 11).
Sexual dysfunction is common in this population. Therefore, Surbeck et al. suggest that sexual health should consistently be addressed during routine pre- and postoperative examination of patients with DLGG 12).