Correlation of the extent of tumor volume resection and patient survival in surgery of new-onset adult supratentorial glioblastoma

Objective To investigate the correlation of extent of resection (EOR) as well as residual tumor volume (RTV) and prognosis of new-onset adult supratentorial glioblastoma (GBM). Methods A retrospective review of 98 adult patients was conducted who were diagnosed with supratentorial GBM and admitted to Department of Neurosurgery, Henan Provincical People's Hospital from January 2010 to December 2013. All patients in this group underwent primary resection of tumors, while some followed by standardized radiotherapy and chemotherapy. Quantitative analysis of pre- and postoperative tumor volumes were conducted, and the Cox proportional hazards regression model was utilized to study the correlation of EOR as well as RTV and the patients' progression-free survival (PFS) and overall survival (OS). The mean period of follow-up was 13.3 (5.9-27.5) months. Results All patients were successfully followed up.Among them, 5 (5%) patients were alive at the final follow-up. The OS and PFS were 13.3±4.9 months and 9.5±4.2 months, respectively. The RTV was 2.82±3.61 cm3, equating to an EOR of 0.91±0.12. Both RTV(P=0.000) and EOR(P=0.000) were statistically significant predictors of survival when controlling for age, Karnofsky performance score (KPS) and adjuvant postoperative therapies. A statistically significant benefit in survival was seen with a RTV no more than 5.5 cm3 or an EOR greater than 0.85. But the relevance of EOR and survival was inexistent when EOR (P=0.880, P=0.665) and RTV(P=0.000, P=0.000)were simultaneously taken in, which suggested that RTV rather than EOR was an independent predictor of survival. Conclusion RTV was found to be a significant predictor of survival for patients with new-onset adult supratentorial GBM. Key words: Glioblastoma; Neurosurgical procedures; Prognosis; Extent of resection; Residual tumor volume