(S051) The Role of Temozolomide in the Treatment of Low-Grade Glioma

April 30, 2015

Our preliminary results suggest that the use of temozolomide in the management of low-grade glioma is neither deleterious nor beneficial in terms of PFS. In comparison with the PFS reported by the EORTC 22844/22845 and RTOG 9802 trials, our PFS is markedly worse. This finding is likely attributable to the high median age of our patient population, which is noticeably older and thus assumed to have a poorer prognosis.

Emi J. Yoshida, MD, Alicia Ortega, BA, Chirag G. Patil, MD, MS, Stephen L. Shiao, MD, PhD; Cedars-Sinai Medical Center

BACKGROUND/OBJECTIVE: World Health Organization (WHO) grade II gliomas are relatively slow-growing brain tumors, with 5-year progression-free survival rates ranging widely, from 13% to 70%. A subset of these tumors will transform into high-grade aggressive cancers with dismal prognoses. A number of phase II trials have demonstrated a role for well-tolerated temozolomide in the prevention of tumor progression and malignant transformation, despite a lack of impact on survival. The institutional paradigm at Cedars-Sinai Medical Center is to manage low-grade gliomas with single-agent temozolomide and to reserve radiotherapy for progression. The aim of this study is to report the preliminary results of our experience with temozolomide in the management of low-grade glioma.

MATERIALS AND METHODS: The records of 234 patients diagnosed with WHO grade II glioma at Cedars-Sinai Medical Center from January 1991 to April 2014 were reviewed. Median age was 47.5 years (range: 39.0–60.0 yr). Ninety-four (40.2%) patients were treated with temozolomide +/− radiotherapy after surgery. Surgery included biopsy (75 patients, 33.8%), subtotal resection (56 patients, 25.2%), and gross total resection (91 patients, 40.9%). Median follow-up time was 51.0 months (range: 25.0–84.4 mo). Statistical analysis controlled for tumor histology, tumor size, extent of resection, and patient age. P values < .05 were considered statistically significant.

RESULTS: Of the 234 patients analyzed, 211 patients recurred or progressed (90.2%). Average time to progression was 42.7 months among patients treated with temozolomide +/− radiotherapy compared with 46.5 months among patients who did not receive temozolomide (P = .35). Five-year progression-free survival (PFS) was 20.7% in those who received temozolomide +/− radiotherapy compared with 29.5% among those who were observed +/− radiotherapy.

CONCLUSION: Temozolomide has become widely used as a primary intervention for low-grade glioma in the past decade. Our preliminary results suggest that the use of temozolomide in the management of low-grade glioma is neither deleterious nor beneficial in terms of PFS. In comparison with the PFS reported by the European Organisation for Research and Treatment of Cancer (EORTC) 22844/22845 and Radiation Therapy Oncology Group (RTOG) 9802 trials, our PFS is markedly worse. This finding is likely attributable to the high median age of our patient population, which is noticeably older and thus assumed to have a poorer prognosis. Ongoing studies are investigating the impact of temozolomide on time to radiotherapy and examining survival outcomes after concurrent temozolomide and radiotherapy.

Proceedings of the 97th Annual Meeting of the American Radium Society - americanradiumsociety.org