Treatment remains controversial for patients diagnosed with a low-risk, low-grade glioma (LGG) brain tumor. These patients have significantly better prognosis than patients diagnosed with more aggressive high-grade glioma, and their clinical care often involves ongoing observation for tumor changes with imaging studies. Because low-risk LGG are slow growing tumors, concerns about the potential adverse effects of early treatment on patients' neurocognitive function (NCF) and quality of life (QOL) may outweigh treatment benefits in patients who are frequently young and highly functional.
Although a low-grade tumor, LGG has a significant potential for transforming into a high-grade glioma. "Currently there is no consensus on when and how best to treat this tumor," says RTOG 0925 principal investigator Ali K. Choucair, M.D., Director of Neuro-oncology and Co-director of the Brain Tumor Center at the Neuroscience Institute, Norton Healthcare System, Louisville, KY. "The RTOG 0925 study was designed with compilation of best available data from both prospective as well as retrospective studies in an effort to identify early clinical and neurocognitive changes that could precede changes observed on imaging scans and could trigger early and timely treatment," Choucair explains.
The study's goal is to better understand the affects of tumor progression on patients with low-risk LGG. The phase II trial will enroll 170 study participants with newly diagnosed LGG who are undergoing observation alone for clinical care. The study will compare NCF, QOL, and seizure control over time in patients who have evidence of tumor progression versus patients who have no evidence of progression as determined by magnetic imaging resonance (MRI) scans. "Standardized and clinically meaningful definitions of tumor progression in low-risk LGG are clearly needed to further the examination and understanding of these tumors," says Walter J. Curran, Jr., MD, RTOG Group Chair, and Executive Director of the Winship Cancer Institute of Emory University in Atlanta, "It is hoped the study's findings will help guide future treatment decisions for these patients," Curran concludes.
The study also has an important translational research component that is expected to contribute much needed information to current limited knowledge about the role molecular markers in predicting LGG tumor progression. Tumor tissue from consenting study participants will be used to evaluate molecular correlates of NCF, QOL, seizure control, and progression-free survival. Such information has the potential to aid clinical decision-making and further the identification of individualized patient therapy approaches.
Patients who have disease progression while enrolled on RTOG 0925 may be eligible for entry on a trial available to RTOG members through the NCI Clinical Trials Support Unit (CTSU) sponsored by ECOG, E3F05/RTOG 1072, Phase III Randomized Study of Radiotherapy With Versus Without Temozolomide in Patients With Symptomatic or Progressive Low-Grade Gliomas.