Gross Total Resection Offers Best Glioblastoma Multiforme Survival

Gross total resection improves overall and disease-free survival in patients with glioblastoma multiforme compared with subtotal surgery

medwireNews: Extent of resection predicts overall survival in patients with glioblastoma multiforme (GBM), confirm the results of a systematic review and meta-analysis.

Data collated from 41,117 GBM patients in 37 studies indicated that risk of mortality was significantly lower in those who underwent gross total resection (GTR) than their counterparts who underwent subtotal resection (STR), with a relative risk (RR) of 0.62 at 1 year and 0.84 at 2 years. The corresponding numbers needed to treat (NNT) to prevent one death were nine and 17.

And receipt of any surgery significantly reduced the 1- and 2-year rate of mortality compared with biopsy alone, with RRs of 0.77 and 0.94, respectively, and NNT of 21 and 593.

GTR was also associated with a significantly reduced risk of disease progression at 1 year compared with STR, with an RR of 0.66 and an NNT of 26, report Michael Glantz, from Penn State Milton S. Hershey Medical Center in Pennsylvania, USA, and co-authors.

STR offered a significantly reduced risk of progression at 6 months compared with biopsy (RR=0.72, NNT=321), as did any resection versus biopsy (RR=0.61, NTT=330), although neither comparison significantly differed at 1 year.

Writing in JAMA Oncology, the researchers admit that the supporting evidence quality is “moderate to low”, noting that the available studies are retrospective and have a high risk of bias and confounding, such as significant differences in prognostic variables between GTR and STR patient groups.

Nevertheless, the authors says that the “overwhelming consistency of the evidence (including three class 2 studies) supports the superiority of GTR over STR and biopsy”.

They believe that further retrospective studies will not contribute useful data and acknowledge that randomised clinical trials have “not proved feasible” for this population.

Michael Glantz et al therefore recommend: “A high-quality, audited, prospective registry of patients with GBM represents a valuable alternative for identifying factors that affect patient outcomes such as [extent of resection], adjuvant therapies, molecular data, preoperative and postoperative imaging, tumor size, topography, location, and medical comorbidities, and should be a critical priority for neurosurgical and oncology communities.”

Reference

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

medwireNews (www.medwireNews.com) is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2016