The extent of resection in patients with glioblastoma, an aggressive and often fatal brain tumor, was associated with the likelihood of survival and disease progression, according to a new study.
Glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults. The optimal combination of medical, surgical, and radiation therapy has not been defined. The surgical component can range from minimally invasive biopsy to a craniotomy (opening of the skull) with the goal of gross total resection (GTR). But not every patient receives an aggressive resection. The anatomy of the brain and concern about injury to important surrounding structures with resulting impairment mean the goal of GTR can be difficult to attain.
Michael Glantz, M.D., of the Penn State Milton S. Hershey Medical Center, Hershey, Penn., and coauthors compared GTR with subtotal resection (STR) or biopsy with overall and progression-free survival in a meta-analysis of 37 studies (41,117 patients).
The study reports a lower relative risk of death at 1 and 2 years. The authors suggest GTR may increase the likelihood of 1-year survival compared with STR by about 61 percent and may increase the likelihood of 2-year survival by about 19 percent. The 1-year risk for mortality for STR compared with biopsy was reduced and the risk for mortality was less for any resection compared with biopsy at years 1 and 2, according to the results.
Overall, a reduction in mortality was associated with an increasing extent of resection. GTR also was associated with decreased disease progression over 1 year, according to the results.
The authors note the results should be interpreted in the context of important caveats, including that GTR and STR groups differed on a number of factors and that the extent of tumor resection was defined by authors in studies, often imprecisely.
"Although the available studies are retrospective and mostly carry a high risk for bias and confounding, an overwhelming consistency of the evidence (including three class 2 studies) supports the superiority of GTR over STR and biopsy. ... Therefore, when clinically feasible, the body of literature favors GTR in all patients with newly diagnosed GBM," the authors conclude.
Illustration: Histopathological image of cerebral glioblastoma. Hematoxylin & esoin stain. Wikipedia.
The JAMA Network News Release (06/16/16)
Science Daily (06/16/16)
Abstract (JAMA Oncology; 2016.)