Gross total resection (GTR) to treat glioblastoma multiforme (GBM) showed progression-free survival (PFS) benefits over subtotal resection (STR) and biopsy in a meta-analysis of 37 studies. GBM is the most frequent brain malignancy in adults and is usually fatal.1

Clinicians have not identified the best treatment combination for treating GBM. Options include medical, surgical, and radiation therapies. Surgery can vary from minimally invasive (eg, biopsy) to quite invasive (eg, craniotomy for GTR). Not all patients undergo GTR as concerns about damage to important surrounding tissues limit its application.

In a systematic review, researchers compared outcomes of GTR with STR and biopsy from 37 studies conducted between January 1966 and December 2015 that included 41 117 patients with GBM. They assessed relative risk (RR) for mortality at 1 and 2 years and PFS at 6 months and 1 year.

This study revealed decreased mortality for GTR compared with STR at 1 year (RR, 0.62; 95% CI, 0.56-0.69; P < .001) and 2 years (RR, 0.84; 95% CI, 0.79-0.89; P < .001). The risk of mortality at 1 year with STR was reduced compared with biopsy (RR, 0.85; 95% CI, 0.80-0.91; P < .001). Compared with biopsy, the risk for mortality with any resection was less at 1 year (RR, 0.77; 95% CI, 0.71-0.84; P < .001) and 2 years (RR, 0.94; 95% CI, 0.89-1.00; P = .04).

Progression-free survival was improved with GTR compared with STR at 1 year (RR, 0.66; 95% CI, 0.43-0.99; P < .001). The quality of the available evidence was low by the Grading of Recommendations Assessment, Development, and Evaluation criteria.

“This analysis represents the largest systematic review and only quantitative systematic review to date performed on this subject. Compared with STR, GTR substantially improves overall and progression-free survival, but the quality of the supporting evidence is moderate to low,” concluded the authors.

Reference

1. Brown TJ, Brennan MC, Li M, et al. Association of the extent of resection with survival in glioblastoma: a systematic review and meta-analysis [published online June 16, 2016]. JAMA Oncol. doi:10.1001/jamaoncol.2016.1373.