Survival improvement by systemic chemotherapy in adult patients with recurrent glioblastoma multiforme treated with two courses of radiotherapy

Abstract

1578 Background: We evaluated the added value of systemic chemotherapy (CTx) in adult patients with recurrent supratentorial glioblastoma multiforme (GBM) selected to receive local re-treatment (administered as a 2nd course of radiotherapy, RTx). Methods: Retrospective comparison of two patient cohorts treated subsequently during different time periods. All patients had histologically confirmed recurrent GBM. Minimum recurrence-free interval was 4 months. The first cohort (n=26) had surgical resection and standard postoperative external beam RTx followed by a second course of external beam RTx for recurrence (median cumulative dose 102 Gy). None of these patients ever received CTx during the whole course of disease. The more recently treated cohort (after 1999) of 19 patients also had surgical resection and 2 courses of external beam RTx (median cumulative dose 90 Gy). After primary local treatment, 9 of these patients had adjuvant nitrosourea-based CTx. At recurrence, all 19 patients received temozolomide 150–200 mg/m2/day for five days every 4 weeks in addition to RTx. Results: The cohort without CTx had less favorable baseline characteristics, because of their significantly lower median KPS at recurrence (70 vs. 90%, p<0.01) and shorter interval between primary diagnosis and recurrence (12 vs. 16 months, p<0.05). However, these patients were non-significantly younger (median age 44 vs. 50 years, p>0.05). The percentage of patients with secondary GBM was similar (21 vs. 23%, p>0.5). Median survival from re-irradiation was significantly better in the RTx plus CTx group, 9 vs. 5 months (p<0.05). In multivariate analysis, prognosis was significantly improved by CTx. Importantly, there was also an advantage when overall survival from first diagnosis was evaluated, median 24 vs. 19 months (p<0.05). Conclusion: The current data suggest that re-irradiation plus temozolomide is better than re-irradiation alone. CTx led to a prolongation of overall survival from first diagnosis by 5 months. The most intensively treated, prognostically favourable de-novo GBM patients had surgical resection, 2 courses of RTx and 2 different systemic CTx regimens. [Table: see text]