Rapid Early Progression (REP) of Glioblastoma Is an Independent Negative Prognostic Factor: Results From a Systematic Review and Meta-Analysis. (1st October 2022) - Waqar, Mueez
Abstract: AIMS: In patients with newly-diagnosed glioblastoma, rapid early progression (REP) refers to tumour regrowth between surgery and postoperative chemoradiotherapy. This systematic review and meta-analysis aimed to appraise published data on REP to better characterise and understand this phenomenon. METHOD: Systematic searches of MEDLINE, EMBASE and the Cochrane database from inception to 21/10/21. Studies describing the incidence of REP – tumour growth between the postoperative MRI scan and pre-radiotherapy MRI scan in newly-diagnosed glioblastoma, were included. The primary outcome was REP incidence. RESULTS: From 1590 search results, 9 studies were included with 716 patients. The median age was 56.9 years (IQR 54.0- 58.8 years). There was a male predominance with a median male-to-female ratio of 1.4 (IQR 1.1-1.5). The median number of days between MRI scans was 34 days (IQR 18-45 days). The mean incidence rate of REP was 45.9% (range 19.3%-72.0%) and significantly lower in studies employing functional imaging to define REP (p<0.001). REP/non-REP groups were comparable with respect to age (p=0.99), gender (p=0.33) and time between scans (p=0.81). REP was associated with shortened overall survival (HR 1.78, 95% CI 1.30-2.43, p<0.001), shortened progression-free survival (HR 1.78, 95% CI 1.30-2.43, p<0.001), subtotal resection (OR 6.96, 95% CI 4-51-10.73, p<0.001) and IDH wildtype versus mutant tumours (OR 0.20, 95% CI 0.02-0.38, p=0.03). MGMT promoter methylation was not associated with REP (OR 1.29, 95% CI 0.72-2.28, p=0.39). CONCLUSION: REP occurs in almost half of patients with newly-diagnosed glioblastoma and has a strongly negative prognostic effect. Future studies should investigate its biology and effective treatment strategies.