Background: Although the majority of current medulloblastoma adjuvant therapy protocols treat patients with ≥ 1.5 cm2 residual tumor as high risk with increased craniospinal irradiation, the true prognostic significance of extent of resection (EOR) in medulloblastoma is unknown.
Objectives: We sought to synthesize the body of literature on EOR and survival to determine if a definitive association exists.
Data sources/eligibility criteria: A PubMed search was conducted for the terms "medulloblastoma" combined with "extent of resection," "overall survival," "progression free survival," "gross total resection," "near total resection," "partial resection," or "subtotal resection." Studies that performed a statistical analysis of EOR and survival were included.
Results: Sixteen articles including 1489 patients found a statistically significant association between EOR and survival, 20 articles including 2335 patients did not find a significant association between EOR and survival, and 14 articles including 2950 patients had mixed results. The three articles that accounted for molecular subgroup found varying associations between EOR and progression free survival, while no association was found between EOR and overall survival.
Limitations: This review is limited by inconsistent definitions of EOR, the retrospective nature of the articles analyzed, and infrequent use of multivariate statistical analyses.
Conclusions: The prognostic importance of EOR for medulloblastoma is unclear and warrants re-evaluation, particularly in the context of molecular subgrouping.
Keywords: Extent of resection; Medulloblastoma; Residual; Subgroup; Surgery; Survival.