Outcomes following myxopapillary ependymoma resection: the importance of capsule integrity

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>While extent of resection has been shown to correlate with outcomes after myxopapillary ependymoma (MPE) resection, the effect of capsular violation has not been well studied. The role of adjuvant radiation also remains controversial. In this paper the authors' goals were to evaluate outcomes following resection of MPE based on intraoperative capsular violation and to explore the role of adjuvant radiotherapy in cases of capsular violation.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>A retrospective review of patients undergoing resection of MPE at 2 academic institutions between 1990 and 2013 was performed. Cases with dissemination at presentation, less than 12 months of follow-up, or incomplete records were excluded. Extent of resection was defined as en bloc if all visible tumor was removed without capsular violation, gross-total resection (GTR) if all visible tumor was removed, but with capsular violation, and subtotal resection (STR) if a known residual was left at the time of surgery. Postoperative MR images were reviewed to confirm the extent of resection. Primary outcomes were progression-free survival (PFS) and overall recurrence rates. The effects of extent of resection, capsular violation, and adjuvant radiotherapy on recurrence rates and PFS were analyzed using Kaplan-Meier statistics. Associations between recurrence and preoperative variables were evaluated using Fisher exact methods and t-tests where appropriate.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>Of the 107 patients reviewed, 58 patients (53% were male) met inclusion criteria. The mean age at surgery was 40.8 years (range 7–68 years). The median follow-up was 51.5 months (range 12–243 months). Extent of resection was defined as en bloc in 46.5% (n = 27), GTR in 34.5% (n = 20), and STR in 18.9% (n = 11). No recurrences were noted in the en bloc group, compared with 15% (n = 3) and 45% (n = 5) in the GTR and STR groups. En bloc resection was achieved most frequently in tumors involving the conus. Twelve patients (20%) underwent adjuvant radiotherapy following either STR or GTR. The overall recurrence rate was 13.8% (n = 8), and the 5-year PFS was 81%. Capsular violation was associated with a higher recurrence rate (p = 0.005). Adjuvant radiotherapy showed a nonsignificant trend of lower recurrence rates (16.7% vs 31.6%, p = 0.43) and longer PFS at 5 years (83.3% vs 49.9%, p = 0.16) in cases of capsular violation.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>A strong correlation between capsular violation and recurrence was found following removal of MPE and should be assessed when defining extent of resection in future studies. Although the use of adjuvant radiotherapy in cases of capsular violation showed a trend toward improved PFS, further investigation is needed to establish its role as salvage therapy also appears to be effective at halting disease progression.</jats:p></jats:sec>

Myxopapillary ependymoma: a SEER analysis of epidemiology and outcomes

“…Multiple previous reports have investigated outcomes based on extent of surgical resection. It is a near universal finding that GTR improves outcomes, often measured as progression-free survival (PFS); while not statistically significant in this cohort there was a trend towards improvement in OS in patients receiving GTR in this analysis [6][7][8][9][10][11][12][13][14]. The few mean tumor size among those receiving RT (4.6 cm) was significantly larger than among those not receiving RT (3.2 cm, p = 0.0002).…”

Spinal cord ependymoma: a review of the literature and case series of ten patients

“…In cases of MPE, it is important to consider whether maximal resection is worth the potential risk of injury, since evidence of a benefit with GTR is currently lacking for these tumors. Some researchers have suggested that preservation of capsular integrity may be important for preventing recurrence of MPE, however, definitive evidence is currently lacking [34, 35]. Further research is required to define the optimal surgical techniques for preservation of neurologic function and prevention of later recurrence.…”

Case-based review: ependymomas in adults

“…22,23 If possible, en bloc resection is preferable to piecemeal resection, as tumor capsule NeuroOncology Neuro-Oncology Practice violation has been reported to increase the risk of CSF seeding and metastasis, while GTR without tumor capsule violation may be curative. 19,24 Despite its extramedullary location and benign grade, MPE carries a long-term prognosis similar to that of WHO grade II ependymoma, perhaps because of a lower overall GTR rate. 25 Oh et al reported in their meta-analysis no difference in OS or PFS between MPE and grade II ependymoma.…”