For children with high-grade glioma (HGG), an aggressive brain cancer, the chances of survival are improved when surgery is successful in eliminating all visible cancer, reported a study in Neurosurgery (2015; doi:10.1227/NEU.0000000000000845).
In addition to showing better survival with gross total resection (GTR) for children with HGG, the results suggest that this survival benefit is greater in girls with HGG than in boys with HGG.
The study provides “compelling evidence that GTR is even more critical in female patients,” wrote corresponding author Jeffrey P. Greenfield, MD, PhD, associate professor of Neurological Surgery at Weill Cornell Medical College in New York, New York, and colleagues.
The researchers analyzed 97 children, median age 11 years, treated for HGG between 1988 and 2010. High-grade pediatric gliomas are serious but uncommon brain tumors, occurring at a rate of less than 1 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 2-year survival rate was 45%, whereas the survival rate with no cancer progression was 25%.
Complete removal of all visible tumor tissue, GTR, was achieved for one-third of the children. Children who underwent GTR had significantly better overall survival: median 3.4 years vs. 1.6 years for those with partial (subtotal) resection.
In addition, the improvement in survival with complete resection differed by sex. Median overall survival was 8.1 years for girls vs. 2.4 years for boys. When GTR was not achieved, median survival was 1.4 years for both boys and girls.
Survival was also affected by the tumor’s location in the brain, but was similar for patients with different cellular types of HGG. Gross total resection improved the chances of survival free of recurrent or progressive cancer only in children with the specific subtype glioblastoma multiforme.
High-grade gliomas make up about 30% of brain tumors in adults, compared with 8% to 12% in children. 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 HGG, which highlights the need for research to see how differences in glioma-related mutations affect the clinical behavior of the disease.
GTR is already the standard of care; however, the study serves to re-emphasize the importance of removing all visible tumor to improve survival for children with HGG.
“In addition, we found that the benefit of a GTR appears to be much greater for female patients than for male patients,” wrote the researchers. Based on this finding, “[I]t may be even more critical to achieve GTR in female patients and that 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 sex-chromosome, or gender-related gene expression patterns. These differences may help clarify the discrepancy in survival rates for boys and girls with HGG.