Abstract
This study was designed to analyze our treatment results for recurrent GBM (rGBM) and to investigate the change of molecular expression, including C3, programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) on paired primary and recurrent tumor specimens of GBMs and to evaluate the influence of their changes for patients survival. From 2004 to 2015, 170 patients with rGBM were included. Forty-three patients (25.3%) were selected for 2nd operation upon recurrent disease (re-operated group) and 127 patients did not undergo 2nd operation (non-operated group). We also evaluated immunohistochemical expression of immunologic markers of 43 paired surgical specimens from the 1st and 2nd operation. Median overall survival after recurrence (rOS) of re-operated group showed significant longer than that of non-operated group (median: 9.1 months vs 5.6 months, P=0.024), The re-operated group showed relative younger age, better Karnofsky performance scale (KPS), and lower rate of leptomeningeal seeding, and eloquent area involvement. In re-operated group, higher KPS and extent of resection was significantly associated with longer rOS. Among 43 paired surgical specimens from the 1st and 2nd operation, positive expression of PD-L1 was 17 patients (39.5%) after 1st operations and 6 patients (13.9%) after 2nd operations. Changes of PD-L1 expression rate after recurrence were as follows; increased group (n=5, 11.6%), decreased group (n=13, 30.2%), and no change group (n=25, 58.1%). The PD-L1 expression and changes of PD-L1 expression did not affect the survival after recurrence. C3 and PD-1 tumor infiltrating mononuclear cells were not detected in almost all initial and secondary specimens. In some selected patients with a recurred GBM, re-operation could be good treatment option. The PD-L1 expression from the 1st and 2nd operation and changes of PD-L1 expression after recurrence did not influence on survival for GBM patients. However, it needs further investigations to reveal the role of immunity in GBM.