Quality of life in patients with diffuse low-grade glioma

While surgery, radiotherapy, and chemotherapy alone or in combination are important therapeutic options in controlling growth of diffuse low-grade gliomas (DLGG), these same therapies pose risks of neurotoxicity, the most common long-term complications being radiation necrosis, chemotherapy-associated leukoencephalopathy, and cognitive deficits. Currently, there is no consensus on the treatment strategy for these tumors. Because of the relatively slow DLGG growth rate, these patients have a relatively long expected survival with radiographic and clinical stability. Compared to traditional outcome measures like PFS and OS, evaluation of health-related quality of life (HRQOL), typically by use of questionnaires, may be considered time-consuming and burdensome by both the patient and the doctor. Besides, given the relatively low incidence of brain tumors and the ultimately fatal outcome of the disease, also for those harboring DLGG, the interest in HRQOL emerged relatively late in these patients. Moreover, the notion that the tumor and treatment may affect brain functioning and thus the patient's introspective abilities may complicate the use of patient-reported outcome measures. The studies presented in this chapter describe outcomes of both single dimensional and multidimensional methods of studying HRQOL. Although only few studies incorporated HRQOL as primary outcome measure of interest, most studies have embraced the notion that an accurate assessment of HRQOL must be based on patient self-report. In future trials, more sensitive measures of long-term cognitive, functional, and HRQOL outcomes on DLGG patients at important time points over the disease trajectory are needed to better understand the changing needs that take place over time.