It may seem obvious, but a study for the first time has documented that when it is possible to completely excise all visible signs of highly aggressive high-grade glioma in children, the chances of survival are much higher.
The study, published in this month's Neurosurgery (2015;77:443-453), also found that the survival benefit appears to be better for girls than for boys.
"The study provides compelling evidence that gross total resection is even more critical in female patients," the senior author, Jeffrey P. Greenfield, MD, PhD, Associate Professor of Neurosurgery at Weill Cornell Medical College, said in a news release.
He and his colleagues (first author is Heather J. McCrea, MD, PhD) analyzed 97 children, median age of 11, who were treated for high-grade gliomas between 1988 and 2010. The cancers are rare-occurring in fewer than one in 100,000 children and adolescents.
Reflecting the poor prognosis of these aggressive brain cancers, the children had high rates of recurrent or progressive cancer and a substantial mortality rate. The two-year survival rate was 45 percent, while the rate of survival with no cancer progression was 25 percent.
Gross total resection-complete removal of all visible tumor tissue-was achieved for approximately one third of the children, and those patients had a median survival of 3.4 years, compared with 1.6 years when only partial resection (subtotal) was possible.
For those for whom total resection was possible, median overall survival was 8.1 years for girls versus 2.4 years for boys; and the rates for both boys and girls was the same-1.4 years-when only partial resection could be achieved.
Location in Brain
Survival was also affected by the tumor's location in the brain, but was similar for patients with different cellular types of the disease: Gross total resection improved the chances of survival free of recurrent or progressive cancer only in children with glioblastoma multiforme.
High-grade gliomas make up about 30 percent of brain tumors in adults, compared with eight to 12 percent in children. The researchers noted that neurosurgeons previously believed that the factors affecting outcomes were similar for all age groups. But recent genetic studies have shown clear distinctions between pediatric and adult patients-highlighting the need for research to see how differences in glioma-related mutations affect the clinical behavior of the disease.
"While gross total resection [GTR] is already the standard of care, the study re-emphasizes the importance of removing all visible tumor to improve survival for children with these cancers," the team wrote. "Based on this finding, it may be even more critical to achieve GTR in female patients and there may be differences between the biology of tumors in male and female patients.
Emphasis is currently directed towards studies exploring the impact of different genetic and molecular subtypes, particularly with respect to understanding the potential impact of gender-related gene expression patterns-differences that may help clarify this discrepancy in survival rates for boys and girls, the researchers said.