Background: The role of extent of surgical resection (EOR) on clinical outcomes in patients with low-grade glioma requires further examination. Methods: We systematically searched MEDLINE, Embase, and the Cochrane Library for studies published between January 1, 1990 and January 5, 2018 on predefined patient outcomes regarding different EOR of low-grade glioma. Results: Our literature search yielded 60 studies including 13,289 patients. Pooled estimates of overall survival showed an increase from 3.79 years (95% CI, 2.37–5.22) in the biopsy group to 6.68 years (95% CI, 4.19–9.16) in STR to 10.65 years (95% CI, 6.78–14.52) in GTR. When compared to STR, GTR prolonged progression-free survival by 2.08 years (95% CI, 0.26–3.89; P=0.025). Pooled estimates of seizure control showed an improvement from 47.8% (95% CI, 26.7–69.6) with biopsy to 54.2% (95% CI, 48.7–59.6) with STR to 81.0% (95% CI, 74.6–86.2) with GTR. Compared to STR, GTR delayed malignant transformation (RR, 0.43; 95% CI, 0.20–0.93; P=0.032), without increasing postoperative mortality (RR, 0.38; 95% CI, 0.07–1.97; P=0.250) or morbidity (RR, 1.22; 95% CI, 0.65–2.28; P=0.540). Conclusions: Among patients with low grade gliomas, higher degrees of safe EOR, were associated with longer overall and progression-free survival, better seizure control, and delayed malignant transformation, without increased mortality or morbidity.
RTHP-31. LOW GRADE GLIOMA MALIGNANT TRANSFORMATION (MT): CLINICAL OUTCOMES AND PROGNOSTIC FACTORS IN TEMOZOLOMIDE ERA
