The influence of surgery on recurrence pattern of glioblastoma

Glioblastoma recurs within 2 cm from the primary tumor's margins in 90-95% of cases. Natural history of recurrence is not well defined. The aim of this study was to verify if pattern of recurrence can be influenced by the extent of surgery. PATIENTS AND METHODS: 131 patients with glioblastoma underwent tumor removal, followed by standard adjuvant radio-chemotherapy. Depending on the amount of apparently normal white matter measured around the tumor in the surgical specimen, the extent of surgery was classified into: "border resection" (BR, resection margins at the level of tumor border) or "extended resection" (ER, resection margins 1-2 cm far from tumor border). 88 patients had no residual tumor at post-operative MRI. Among these, 60 patients had a local recurrence (LR) - within 2 cm from the primary tumor's margins, 15 patients had a distant recurrence (DR), 13 patients had no recurrence. Survival curves were obtained through the Kaplan-Meier method. Dichotomous data were compared with the chi-square test. RESULTS: Patients who underwent ER presented a LR in 67% of cases. Patients who underwent BR presented a LR in 87.5% of cases (p=0.03). Survival for 60 patients with LR was 16 months vs 35 months for 15 patients with DR (p=0.06). PFS for patients with LR was 9 months vs 21 months for patients with DR (p=0.05). CONCLUSIONS: If tumor grows far from eloquent areas, ER may increase the probability to obtain a gross total resection, a greater number of patients with DR and, therefore, a longer survival.