Clinical StudyThe survival significance of a measurable enhancing lesion after completing standard treatment for newly diagnosed glioblastoma

- Natural prognosis in patients with a residual lesion after standard treatment for newly diagnosed glioblastoma, is unclear.
- Poor survival outcome was found only in patients who exhibited progressive disease after standard treatment.
- No further management may be needed for a patient who shows partial remission or standard disease after standard treatment.

The goal of this study was to analyze the survival outcome according to the treatment response after completing standard treatment protocol for newly diagnosed glioblastoma (GBM) and to suggest a patient who should be considered for further treatment. After approving by our Institutional Review Board, 57 patients (38 male, 19 female; median age, 52 years; age range, 16-81 years) with newly diagnosed GBM who completed standard treatment protocol were examined retrospectively. According to the treatment response using the RANO criteria, there were 20 patients with complete response (CR), five patients with partial response (PR), 13 patients with stable disease (SD) and 19 patients with progressive disease (PD) after the completion of standard treatment. Patients (PR + SD + PD) with a measurable enhancing lesion were categorized the MEL group (n = 37). We analyzed the difference of survival outcome between CR group and MEL group. The median progression-free survival (PFS) in the CR group was significantly better than that of the MEL group (18.0 months vs. 3.0 months, p = 0.004). The median overall survival (OS) was also significantly longer in the CR group (25.0 months vs. 15.0 months, p = 0.005). However, there was no significant difference in the survival outcome of the CR group compared with that of the subset of MEL group patients who showed PR or SD. Poor survival outcome was found only in MEL group patients who exhibited progression. Patients with a measurable enhancing lesion showing progression after completion of standard treatment protocol are appropriate candidates for further treatment.