title: Spinal ependymomas: benefits of extent of resection for different histological grades.
abstract: Although the World Health Organization (WHO) categorizes spinal ependymomas into three histological grades, difference in surgical outcomes between WHO grades I and II tumors are unclear. For these benign tumors, prognosis may be best determined by factors other than tumor grade alone, such as extent of resection. To analyze the effects of the extent of resection on different grades of spinal ependymomas, we performed a comprehensive literature review to identify adult spinal ependymoma patients who received surgical resection with a clearly identifiable WHO grade. A total of 175 patients were identified. While grade III tumors carried the worst prognosis as expected (p<0.001), grade I and II tumors did not differ significantly in outcomes following surgery. Overall, gross total resection (GTR, 68.7%, 114/166) provided significantly improved progression-free survival (PFS, p<0.001) and overall survival (OS, p=0.022) compared to the subtotal resection group. Surprisingly, the highest GTR rate was achieved for grade II tumors (78.8%, 78/99; p<0.001) followed by grade I (58.9%, 33/56) and grade III tumors (27.3%, 3/11). Interestingly, PFS was significantly improved by GTR for grade II tumors (p<0.001), but not for grade I (p=0.705). Similar trends, although not statistically significant, were found for OS. Our results show that while GTR provides the best overall outcomes, GTR is most effective for classic grade II ependymomas, but not for grade I ependymomas. Despite having a lower WHO grade, myxopapillary ependymomas have a lower GTR rate, and benefit less from GTR.
authors.affiliation: Department of Neurological Surgery, University of California San Fransisco, 505 Parnassus Avenue, San Francisco, CA 94117, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Oh
authors.forename: Phiroz E
authors.initials: PE
authors.lastname: Tarapore
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Kim
authors.forename: Matthew Z
authors.initials: MZ
authors.lastname: Sun
authors.forename: Michael
authors.initials: M
authors.lastname: Safaee
authors.forename: Gurvinder
authors.initials: G
authors.lastname: Kaur
authors.forename: Derick M
authors.initials: DM
authors.lastname: Aranda
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Parsa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D018572:Disease-Free Survival; D004806:Ependymoma / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D013120:Spinal Cord Neoplasms / Q000401:mortality / Q000601:surgery*; D015599:Trauma Severity Indices; D055815:Young Adult
keywords: Ependymoma; Extent of resection; Recurrence; Spine; Tumor grade