A study conducted in Norway showed that for patients with low-grade gliomas, treatment at a university hospital favoring early surgical resection was associated with better overall survival than was treatment at a university hospital favoring biopsy and watchful waiting.
As Asgeir S. Jakola, MD, of St. Olavs University Hospital in Trondheim, Norway, and fellow investigators pointed out in their JAMA report, low-grade gliomas usually are not considered surgically curable due to diffuse brain infiltration. “In fact, the effect of surgery remains unclear because current evidence relies on uncontrolled surgical series alone,” noted the researchers.
To examine survival in population-based parallel cohorts of persons with low-grade gliomas, Jakola’s team performed a blinded histopathological review of histopathology specimens from all adult patients at the two centers who had been diagnosed with low-grade gliomas from 1998 through 2009. The two groups of patients were comparable in terms of baseline parameters. Follow-up ended in mid-April 2011; median follow-up was 7.0 years at the center where biopsy and watchful waiting were preferred, and 7.1 years at the center where early tumor resection was preferred.
Initial biopsy alone was carried out in 47 (71%) of the 66 patients served by the center favoring biopsy and watchful waiting, and in only 12 (14%) of the 87 patients served by the center favoring early resection. Overall survival was significantly better at the early-resection facility: By the end of follow-up, 34 (52%) of the patients from the hospital favoring biopsy and watchful waiting had died, compared with 28 (32%) of the patients from the hospital favoring early surgical resection.
At the center favoring biopsy only, median survival was 5.9 years and estimated 5-year survival was 60%, whereas at the center favoring early resection, median survival was not reached and estimated 5-year survival was 74%. The survival benefit remained after adjusting for validated prognostic factors, and increased with time:
- One-year survival was 89% at both centers.
- Expected 3-year survival was 80% for the patients from the surgical-resection center compared with 70% from the center favoring biopsy and watchful waiting.
- Expected 5-year survival was 74% vs 60%, respectively.
- Expected 7-year survival was 68% vs 44%, respectively.