Contemporary Survival Outcomes and Prognostic Factors in Glioblastoma: An Institutional Analysis

Abstract

Abstract Purpose There have been significant advancements in diagnostic radiology and pathology, and in the technical aspects of surgery, radiation therapy and temozolomide used for treatment of glioblastoma. We analyzed the outcomes of 267 adult patients with glioblastoma, consecutively treated between December 2010 and November 2018 using modern techniques at our institute. Methods All patients underwent surgical resection, volumetric modulated arc therapy-based radiation therapy using institute-specific target-delineation guidelines and image-guidance, and temozolomide according to Stupp’s protocol. Serial multiparametric magnetic resonance imaging-based follow-up ensured early detection of disease progression. Appropriate salvage therapy was determined based on clinicopathological attributes. Kaplan-Meier survival plots, log-rank test and Cox regression analysis was performed on the prospectively recorded dataset to estimate survival, and the factors affecting it. Results The median progression-free survival (PFS), 1-year PFS, and 2-year PFS were 10 months, 37.8%, and 17.5%, respectively. Radiation dose ≥ 54 Gy and ≥ 4 adjuvant TMZ cycles were associated with favourable PFS. The median overall survival (OS), 2-year OS and 5-year OS were 24 months, 48% and 18%, respectively. One-year disease control, surgery-use at progression, and systemic therapy-use at progression were associated with favourable OS. Haematological toxicity ≥ Grade 2 was evident in 6% patients during concurrent radiation-temozolomide phase, and in 9% patients in adjuvant temozolomide phase. Post-radiation neurocognitive deficits were noted in 20.1% patients, with onset at a median duration of 10 months. Conclusion Modern diagnostic and therapeutic techniques for glioblastoma effected a near-doubling of survival compared to historical data, with acceptable late toxicity.