Postprogression survival in patients with glioblastoma treated with concurrent chemoradiotherapy: a routine care cohort study.

Glioblastoma is the commonest malignant brain tumor in adults. Most patients develop progressive disease before they die. However, survival after developing progressive disease is infrequently reported. We identified patients with histologically proven disease who were treated with concurrent chemoradiotherapy during 2006-2013. We analyzed overall survival (OS), progression-free survival and postprogression survival (PPS) in relation to age, O6-methylguanine-DNA methyltransferase promoter methylation and extent of surgical resection. We identified 166 patients. Median survival was 13.5 months; 2-year OS was 21.7%. Median progression-free survival and PPS were 7.03 and 4.53 months, respectively. Age and extent of surgical resection were correlated with OS. Only the extent of surgical resection was associated with PPS. Our work suggests that the established prognostic factors for glioblastoma do not appear to help predict PPS.