Ari J. Kane, Michael E. Sughrue, Martin J. Rutkowski, Derick Aranda, Stephen A. Mills, Mandeep Lehil, Shanna Fang and Andrew T. Parsa
The literature, at present, provides limited information about extraventricular neurocytomas (EVNs) and is almost exclusively composed of case reports or small case series. Treatment for EVNs has largely been guided by results from central neurocytoma outcome studies. The authors present an analysis of all reported intracranial EVN cases to establish if tumor histopathological features can substratify EVN into groups with differing prognosis and help guide treatment decisions.
The authors identified studies reporting histology, treatment modality, and outcomes for patients with intracranial EVN. The rates of recurrence and survival for patients were compared using Kaplan-Meier analysis. Atypical tumors, defined by MIB-1 labeling index exceeding 3% or atypical histological features, were compared with typical tumors, and patients 50 years of age or older were compared with those younger than 50 years of age.
Eighty-five patients met the inclusion criteria, and 27% of them had an atypical histology. Typical EVNs had a better prognosis than atypical EVNs after primary treatment, with a 5-year recurrence rate of 36% compared with 68% (p < 0.001), and a 5-year mortality rate of 4% compared with 44%, respectively (p < 0.001). Age younger 50 years was associated with a better prognosis than age equal to or greater than 50 years, with a 5-year recurrence rate of 33% and 74%, respectively (p < 0.001), and a 5-year mortality rate of 4% and 52%, respectively (p < 0.001). Multivariate analysis demonstrated that atypical EVNs carried significantly increased risk for recurrence (hazard ratio [HR] 4.91, p < 0.001) and death (HR 22.91, p < 0.01). Gross-total resection was superior to subtotal resection (STR) alone in tumor control rates for typical EVNs (95% and 68%, p < 0.05), and there was a trend for adjuvant external-beam radiotherapy to benefit STR. There was suggestion of similar trends in patients with atypical EVNs.
There are at least 2 distinct histological subtypes of EVN, with different prognostic significances. Atypia or MIB-1 labeling index greater than 3% is a significant predictor of poor prognosis for EVNs. Complete resection or more aggressive attempts at providing adjuvant therapy following STR appear to improve the prognosis for patients with EVNs. Although the authors' results are informative, there are limitations to their analysis. Given the relatively modest total number of cases reported, as well as the nature of the disaggregated analysis, the authors were not able to use formal meta-analytical methods to limit the impact of between center heterogeneity. Additionally, they were not able to control for individual differences in data analysis and presentation across the different studies included in their analysis.
Michael E. Sughrue, Isaac Yang, Derick Aranda, Martin J. Rutkowski, Shanna Fang, Steven W. Cheung and Andrew T. Parsa
Outcomes following vestibular schwannoma (VS) surgery have been extensively described; however, complication rates reported in the literature vary markedly. In addition, the majority of reports have focused on outcomes related to cranial nerves (CNs) VII and VIII. The objective of this study was to analyze reported morbidity unrelated to CNs VII and VIII following the resection of VS.
The authors performed a comprehensive search of the English language literature, identifying and aggregating morbidity and death data from patients who had undergone microsurgical removal of VSs. A subgroup analysis based on surgical approach and tumor size was performed to compare rates of CSF leakage, vascular injury, neurological deficit, and postoperative infection.
One hundred articles met the inclusion criteria, providing data for 32,870 patients. The overall mortality rate was 0.2% (95% CI 0.1–0.3%). Twenty-two percent of patients (95% CI 21–23%) experienced at least 1 surgically attributable complication unrelated to CNs VII or VIII. Cerebrospinal fluid leakage occurred in 8.5% of patients (95% CI 6.9–10.0%). This rate was markedly increased with the translabyrinthine approach but was not affected by tumor size. Vascular complications, such as ischemic injury or hemorrhage, occurred in 1% of patients (95% CI 0.75–1.2%). Neurological complications occurred in 8.6% of cases (95% CI 7.9–9.3%) and were less likely with the resection of smaller tumors (p < 0.0001) and the use of the translabyrinthine approach (p < 0.0001). Infections occurred in 3.8% of cases (95% CI 3.4–4.3%), and 78% of these infections were meningitis.
This study provides statistically powerful data for practitioners to advise patients about the published risks of surgery for VS unrelated to compromised CNs VII and VIII.
2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010
Ari J. Kane, Michael E. Sughrue, Martin J. Rutkowski, Derick Aranda, Steve A. Mills, Raphael Buencamino, Shanna Fang, Igor J. Barani and Andrew T. Parsa
There is no Class I evidence to guide the appropriate management of esthesioneuroblastoma (EN). Most data currently guiding treatment come from small- or modest-sized series gathered at individual centers that have concluded that surgery with radiotherapy is the preferred treatment. In this study, the authors summarize the published literature on treatment outcomes in patients with EN. The objective was to ascertain what variables predict prognosis in these patients and to determine the relative effect of different therapies.
The authors identified 205 published studies containing treatment outcomes for surgery, radiotherapy, chemotherapy, or multimodal treatment. Using Kaplan-Meier analysis, the survival of patients who received surgery was compared with that in those who received surgery and radiotherapy. Additionally, Kadish staging was compared with low- and high-grade Hyams criteria to assess for subgroup prognostic significance in survival differences.
Nine hundred fifty-six patients met the inclusion criteria, with a median follow-up time of 3 years. Kaplan-Meier analysis demonstrated no difference in survival between patients who underwent surgery alone and those who underwent surgery plus radiotherapy at 5 years (78 vs 75%) or 10 years (67 vs 61%, respectively) (p = 0.3). Univariate analysis demonstrated worse survival in cases involving Kadish Grade C tumors, Hyams Grade 3 and 4 tumors, and in patients older than 65 years of age. Multivariate analysis demonstrated that Hyams Grade 3 and 4 lesions carried significant risk (proportional hazard = 4.83, p < 0.001) with 5- and 10-year survival of 47 and 31%.
A biopsy should always be obtained in cases suspected of EN because histology is a strong prognostic indicator and will help guide appropriate treatment. Unimodal surgery and combined surgery/radiotherapy appear to be of equivalent efficacy with respect to survival in patients with EN. Chemotherapy should be considered in high-grade EN.