Extent of Surgical Resection and Clinical Presentation Impacts Progression-Free Survival in a Large, Modern Cohort of Spinal Ependymoma Patients

Introduction: Spinal ependymomas are the most common glial spinal tumor in adults. Primary treatment involves surgical resection, however reported recurrence ranges between 50-70%. While the association of survival outcomes with lesion extent of resection (EOR) has been studied previously, existing analyses are limited by small samples or archaic data that predates the MRI era or widespread implementation of intraoperative microsurgical equipment and techniques. The objective was to investigate the relationship between EOR and survival outcomes, chiefly overall survival (OS) and progression-free survival (PFS), in a large modern cohort of adult patients diagnosed with spinal ependymomas.

Methods: Adult patients (>18 years) diagnosed with a spinal ependymoma from 2006-2021 were identified from an institutional tumor board registry. Inclusion criteria included patients undergoing primary surgical resection at our institution, ≥1 routine follow-up MRI with clinic appointment, and pathologic diagnosis of ependymoma. Patient records were retrospectively reviewed for basic demographic information, extent of resection, lesion grade, location, presence of syrinx, and pre-/post-operative neurologic symptoms. Log-rank test was used to compare OS and PFS between patient groups and Cox proportional hazard model was used to associate multiple patient characteristics with PFS, with p < 0.05 considered significant.

Results: Seventy-three patients satisfied inclusion criteria, with 75.3% patients benefitting from a GTR. The study population was 58.9% male with average age of 46.0 years, and mean follow-up duration of 60.4 months. Log-rank analysis demonstrated a significant improvement in PFS when a GTR was attained (p <.001). Similarly, patients with a syrinx had improved PFS (p=.02) and were more likely to benefit from GTR (p=.04). Patients who were independently ambulatory prior to surgery had statistically superior PFS (p < .001). Alternatively, OS was not affected by EOR (p=.38).

Conclusion : This large, modern series of adult spinal ependymoma patients demonstrated improvements in PFS when GTR was achieved. Future prospective multi-institutional studies are required to validate.