"Author (year, country)";"Study design";"Sample size, age range";Intervention/Procedure;"Follow-up duration";"Outcome measures";"Main findings"
"Fu et al.[2], (2024, China)";"Retrospective cohort study";"126 patients, median age: 49.27 years";"WHO grade, gliosis percentage, MGMT methylation status";"Surgery, radiotherapy, chemotherapy";"Median OS: 838.36 days (approx. 2.3 years)";"At least 2 years"
"Van Linde et al.[12], (2017, Netherlands)";"Retrospective multicenter study";"299 patients, median age: 59 years (range: 19-77)";"Age, tumor extent, extent of initial resection, steroid use, KPS";"Systemic treatment, re-resection, re-irradiation, BSC";"Median OS: 6.5 months (overall), 11 months for SURG";"10 years"
"Audureau et al.[13], (2017, France)";"Retrospective multicenter study";"407 patients (training set), median age: 58 years";"Age, KPS, RTOG–RPA classes, surgical resection, chemotherapy";"Surgical resection, chemotherapy, radiotherapy, best supportive care";"Median OS from progression: 7.6 months";"Not specified"
"Jilla et al.[14], (2022, India)";"Retrospective, single-institutional study";"46 patients, mean age: 48.5 years (range: 21–76)";"Age, adjuvant chemotherapy, anti-epileptic drugs";"Surgery, radiotherapy, chemotherapy (temozolomide)";"1-year OS: 36.9%, 2-year OS: 10.8%, Median OS: 8 months";"Not specified"
"Brown et al.[15], (2022, UK)";"Retrospective cohort study";"490 patients, median age: 59 years";"Age, MGMT promotor methylation, IDH mutation";"Surgery, radiotherapy, chemotherapy (temozolomide)";"Median OS: 9.2 months (range: 7.9–10.3 months)";"Not specified"
"Vaz-Salgado et al.[16], (2023, Spain)";"Retrospective review";"Not specified, median age: > 65 years";"Age, KPS, tumor size, extent of resection";"Surgery, radiotherapy, chemotherapy, immunotherapy, bevacizumab";"Median OS: 14 months (initial treatment); <1 year (recurrence)";"Not specified"
"Fekete et al.[17], (2023, Sweden)";"Retrospective cohort study";"222 patients, median age: 64 years";"Age, MGMT promoter methylation, WHO performance status";"Surgery (CRET), Radiotherapy, Chemotherapy (TMZ)";"Median OS: 1.07 years (12.8 months)";"Until June 2018"
"Hansen et al.[18], (2024, Denmark)";"Retrospective cohort study";"66 patients, median age: 62 years";"KPS <70, Ki-67, ependymal involvement, tumor volume ≧50 cm3";"Surgery, chemotherapy, radiotherapy";"Median OS: 335 days after second surgery";"Until November 2020"
"Karschnia et al.[19], (2023, USA & Germany)";"Retrospective cohort study";"681 patients, median age: 58.8 years";"Age, KPS, MGMT methylation, tumor volume";"Surgery (re-resection), chemotherapy, radiotherapy";"Median OS: 11 months (re-resection), 7 months (no re-resection)";"Until death or loss to follow-up"
"Blakstad et al.[20], (2023, Norway)";"Retrospective cohort study";"467 patients, median age: 61.8 years";"Age, MGMT promoter methylation, tumor location, extent of resection";"Surgery, radiotherapy, chemotherapy, stereotactic radiosurgery";"Median OS: 12.1 months";"Until death or loss to follow-up"
"Schaub et al.[21], (2016, Germany)";"Retrospective cohort study";"174 patients, median age: 54 years";"KPS, number of prior recurrences, number of prior chemotherapies, MGMT status";"Bevacizumab alone or with irinotecan";"Median OS: 7.0 months for BEV alone; 11.3 months for BEV + IRI";"Until death or loss to follow-up"