Phase II Study of a Temozolomide-Based Chemo-radiotherapy Regimen for High Risk Low-Grade Gliomas: Long-term Results of Radiation Therapy Oncology Group (RTOG) 0424.
Fisher BJ, Pugh SL, Macdonald DR, Chakravatri A, Lesser GJ, Fox S, Rogers CL, Werner-Wasik M, Doyle T, Bahary JP, Fiveash JB, Bovi JA, Howard SP, Michael Yu HH, D'Souza D, Laack NN, Barani IJ, Kwok Y, Wahl DR, Strasser JF, Won M, and Mehta MP. Phase II Study of a Temozolomide-Based Chemo-radiotherapy Regimen for High Risk Low-Grade Gliomas: Long-term Results of Radiation Therapy Oncology Group (RTOG) 0424. Int J Radiat Oncol Biol Phys 2020.
International journal of radiation oncology, biology, physics
PURPOSE: To report the long-term outcomes of the YYY1 study of a high-risk low-grade gliomas (LGG) population treated with concurrent and adjuvant temozolomide (TMZ) and radiotherapy (RT).
PATIENTS/METHODS: For this single-arm phase II study, LGG patients with >3 risk factors (age >40, astrocytoma, bi-hemispheric tumor, size >6 cm or preoperative neurologic function status >1) received RT (54 Gy/30 fractions) with TMZ and up to 12 cycles of post-RT TMZ. The initial primary endpoint p was overall survival (OS) at 3 years after registration. Secondary endpoints included: progression-free survival (PFS), and the association of survival outcomes with methylation status. The initial 3 year report of this study was published in 2015.
RESULTS: The study accrued 136 patients, of whom 129 were analyzable. The median follow-up for surviving patients is 9.0 years. The 3-year OS is 73.5% (95% CI: 65.8-81.1%), numerically superior to the 3 year OS historical control(1) OS of 54% (p<0.001). The median survival time is 8.2 years (95% CI: 5.6-9.1). Five- and 10-year OS rates are 60.9% and 34.6% respectively and 5- and 10-year PFS rates are 46.8% and 25.5% respectively.
CONCLUSIONS: The long-term results confirmed the findings from the initial report for efficacy suggesting OS and PFS outcomes with the RT-TMZ regimen exceeding historical control control groups treated with radiation alone. Toxicity was acceptable.
ePub ahead of print