Tumor-treating fields as a fourth treating modality for glioblastoma: a meta-analysis

Background We aim to review the available literature on patients suffering from glioblastoma treated with tumor-treating fields (TTFields) plus radio chemotherapy or conventional radio chemotherapy alone, to compare the efficacy and safety of the two methods. Methods A systematic literature search was performed in PubMed, Cochrane library, and Scopus databases, in accordance with the PRISMA guidelines. Six studies met the inclusion criteria incorporating 1806 patients for the qualitative analysis and 1769 for the quantitative analysis. Results This study reveals increased median overall survival (weighted mean difference (WMD) 3.29 [95% confidence interval (CI) 2.37, 4.21]; p < 0.00001), survival at 1 year (odds ratio (OR) 1.81 [95% CI 1.41, 2.32]; p < 0.00001) and 2 years (OR 2.33 [95% CI 1.73, 3.14]; p < 0.00001), and median progression-free survival (WMD 2.35 [95% CI 1.76, 2.93]; p < 0.00001) along with progression-free survival at 6 months (WMD 6.86 [95% CI 5.91, 7.81]; p < 0.00001) for the patients treated with TTFields. Survival at 3 years was comparable between the two groups. TTFields were associated with fewer adverse events compared to chemotherapy along with similar incidence of skin irritation. Conclusions TTFields are a safe and efficient novel treatment modality. More randomized controlled studies, with longer follow-up, are necessary to further assess the clinical outcomes of TTFields.