Relationship between the extent of resection and the survival of patients with low-grade gliomas: a systematic review and meta-analysis

Background: Surgical resection is necessary to conduct a pathological biopsy and to achieve a reduction of intracranial pressure in low-grade gliomas patients. This study aimed to determine whether a greater extent of resection would increase the overall 5-year and 10-year survival of patients with low-grade gliomas. Methods: The studies addressing relationship between the extent of resection and the prognosis of low-grade gliomas updated until March 2017 were systematically searched in two databases (Pubmed and EMBASE). The relationships among categorical variables were analyzed using an odds ratio (OR) and a 95% confidence interval (CI). Significance was established using CIs at a level of 95% or P < 0.05. Funnel plot was used to detect the publication bias. Results: Twenty articles (a total of 2128 patients) were identified. The meta-analysis showed that the 5-year (Odds ratio (OR), 3.90; 95% Confidence Interval (CI), 2.79 similar to 5.45; P < 0.01; Z = 7.95) and 10-year OS (OR, 7.91; 95% CI, 5.12 similar to 12.22; P < 0.01; Z = 9.33) associated with gross total resection (GTR) were higher than those associated with subtotal resection (STR). Similarly, as compared with biopsy (BX), the 5-year and 10-year OS were higher after either GTR (5-year: OR, 5.43; 95% CI, 3.57 similar to 8.26; P< 0.01; Z = Z = 7.9; 10-year: OR, 10.17; 95% CI, 4.02 similar to 25.71; P < 0.00001; Z = 4.9) or STR (5-year: OR, 2.59; 95% CI, 1.81 similar to -3.71; P< 0.00001; Z = 5.19; 10-year: OR, 2.21; 95% CI, 1.164.25; P = 0.02; Z = 2.39). Conclusions: Our research found that a greater extent of resection could significantly increase the OS of patients with low-grade gliomas.