P14.62 Overall survival from glioblastoma: partial resection versus biopsy

BACKGROUND Maximal safe resection is standard of care in patients with glioblastoma. Partial resection or biopsy are alternative surgical approaches when macroscopic complete resection is unachievable. Survival benefit from partial resection remains uncertain. We aimed to evaluate overall survival from glioblastoma in patients having undergone partial resection compared to biopsy. MATERIAL AND METHODS We retrospectively identified all patients with histologically confirmed glioblastoma having undergone partial resection or biopsy in Western Norway between 1.1.2007 and 31.12.2014. Clinical characteristics and radiology reports were extracted from electronic medical records. Categorical data were compared by chi square test or Fishers exact test, and continuous data by non-parametric tests. Kaplan Meier method and log rank test were used for survival analyses. RESULTS We identified 158 patients diagnosed with glioblastoma and having undergone biopsy or partial resection. Biopsy was performed in 52 patients (32.9%) and partial resection in 106 patients (67.1%). Median age (range) was 62.5 (18.1–82.3) in the biopsy group and 62.2 (27.9–85.1) in the partial resection group (p=0.90). Median Charlson comorbidity score was four in both groups. Multifocality was observed in 46.2% of patients in the biopsy group, compared to 27.4% of patients in the partial resection group (p=0.02). Deep-seated tumour localisation was also more frequent in the biopsy group than in the partial resection group, seen in 17.3% vs 5.7% of the patients (p=0.04). There was no difference in chemoradiotherapy (CRT) treatment between the groups. CRT according to the Stupp protocol, less intensive CRT and best supportive care was performed in 36.5%, 50.0% and 13.5% of patients in the biopsy group, compared to 45.3%, 49.1% and 5.7% in the partial resection group (p=0.20). Median overall survival in the biopsy group was 8.1 months (95% CI 5.2–11.1) compared to 11.1 months (95% CI 9.4–12.8) in the partial resection group (p=0.19). Median survival in the biopsy group was 13.8 months (95% CI 10.1–17.5), 6.5 months (95% CI 3.6–9.4), and 3.5 months (95% CI 0.0–7.7) for patients receiving CRT according to Stupp protocol, less-intensive CRT and best supportive care, respectively (p<0.001). The corresponding numbers in the partial resection group were 15.1 months (95% CI 13.2–16.9), 9.1 months (95% CI 7.5–10.6), and 1.5 month (95% CI 0.0–4.7) (p<0.001). CONCLUSION Median overall survival was slightly longer in patients having undergone partial resection compared to biopsy, however not statistically significant. Prospective studies are needed to evaluate the survival benefit from partial resection.