Multiple tumors worsen glioblastoma prognosis
Persons who have more than one glioblastoma tumor upon diagnosis experience significantly worse survival than do patients with a solitary lesion, demonstrate the findings of a new study.
Patients with glioblastoma multiforme, the most common and aggressive malignant tumor occurring in the brain, typically survive 15 months when undergoing standard treatment. However, the prognosis of patients who present with multiple glioblastoma tumors, or multifocal disease, is not well documented.
To determine whether multifocal disease on initial presentation is associated with worse survival among persons with glioblastoma, Chirag G. Patil, MD, MS, director of the Center for Neurosurgical Outcomes Research at Cedars-Sinai Medical Center in Los Angeles, California, and colleagues conducted a retrospective review of 368 patients with newly diagnosed glioblastoma. The team identified 47 individuals (12.8%) as having multifocal tumors, and compared them with 47 patients with only a single lesion. The two sets of patients were closely matched on the basis of age, functional impairment scores on the Karnofsky Performance Scale (KPS), and extent of tumor removal and radiation therapy and chemotherapy.
Among the patients with multifocal tumors (median age 61 years), 87.2% had undergone either a biopsy or partial resection of their tumors, and 76.6% had a KPS score of 70 or higher, indicating relatively little functional impairment. Age older than 65 years, partial resection or biopsy, and a low KPS score (below 70) were associated with worse median survival in the multifocal group compared with the matched unifocal patients.
As the investigators reported in Journal of Neurosurgery, 19 patients in the multifocal group experienced tumor progression on postradiotherapy magnetic resonance imaging, compared with 11 of the matched patients in the unifocal group. Persons with multifocal tumors had significantly shorter median overall survival: 6 months, compared with 11 months for the matched patients with solitary tumors. Two-year survival rates were 4.3% in the multifocal group and 29% in the unifocal cohort. Patients with newly diagnosed multifocal tumors had an almost twofold increase in the hazard of death compared with the patients with solitary glioblastoma (hazard ratio 1.8).
“Our study appears to confirm observations that disease in patients with more than one lesion is particularly challenging and that these patients tend to have worse outcomes,” noted Patil in a statement issued by Cedars-Sinai Medical Center. He also explained that researchers believe cells of multifocal tumors may have an increased ability to migrate in the brain and invade normal tissue, leading to more rapid patient decline.