Michael E. Sughrue, Rajwant Kaur, Martin J. Rutkowski, Ari J. Kane, Gurvinder Kaur, Isaac Yang, Lawrence H. Pitts and Andrew T. Parsa
With limited studies available, the correlation between the extent of resection and tumor recurrence in vestibular schwannomas (VSs) has not been definitively established. In this prospective study, the authors evaluated 772 patients who underwent microsurgical resection of VSs to analyze the association between total tumor resection and the tumor recurrence rate.
The authors selected all cases from a prospectively collected database of patients who underwent microsurgical resection as their initial treatment for a histopathologically confirmed VS. Recurrence-free survival was analyzed using Kaplan-Meier analysis. The authors studied the impact of possible confounders such as patient age and tumor size using stepwise Cox regression to calculate the proportional hazard ratio of recurrence while controlling for other cofounding variables.
The authors analyzed data obtained in 571, 89, and 112 patients in whom gross-total, near-total, and subtotal resections, respectively, were performed. A gross-total resection was achieved in 74% of the patients, and the overall recurrence rate in these patients 8.8%. There was no significant relation between the extent of resection and the rate of tumor recurrence (p = 0.58). As expected, the extent of resection was highly correlated with patient age, tumor size, and surgical approach (p < 0.0001). Using Cox regression, the authors found that the approach used did not significantly affect tumor control when the extent of resection was controlled for.
While complete tumor removal is ideal, the results presented here suggest that there is no significant relationship between the extent of resection and tumor recurrence.
Isaac Yang, Michael E. Sughrue, Martin J. Rutkowski, Rajwant Kaur, Michael E. Ivan, Derick Aranda, Igor J. Barani and Andrew T. Parsa
Craniopharyngiomas have a propensity to recur after resection, potentially causing death through their aggressive local behavior in their critical site of origin. Recent data suggest that subtotal resection (STR) followed by adjuvant radiotherapy (XRT) may be an appealing substitute for gross-total resection (GTR), providing similar rates of tumor control without the morbidity associated with aggressive resection. Here, the authors summarize the published literature regarding rates of tumor control with various treatment modalities for craniopharyngiomas.
The authors performed a comprehensive search of the English language literature to identify studies publishing outcome data on patients undergoing surgery for craniopharyngioma. Rates of progression-free survival (PFS) and overall survival (OS) were determined through Kaplan-Meier analysis.
There were 442 patients who underwent tumor resection. Among these patients, GTR was achieved in 256 cases (58%), STR in 101 cases (23%), and STR+XRT in 85 cases (19%). The 2- and 5-year PFS rates for the GTR group versus the STR+XRT group were 88 versus 91%, and 67 versus 69%, respectively. The 5- and 10-year OS rates for the GTR group versus the STR+XRT group were 98 versus 99%, and 98 versus 95%, respectively. There was no significant difference in PFS (log-rank test) or OS with GTR (log-rank test).
Given the relative rarity of craniopharyngioma, this study provides estimates of outcome for a variety of treatment combinations, as not all treatments are an option for all patients with these tumors.
Michael E. Sughrue, Rajwant Kaur, Ari J. Kane, Martin J. Rutkowski, Isaac Yang, Lawrence H. Pitts, Tarik Tihan and Andrew T. Parsa
Vestibular schwannomas (VSs) are benign lesions with an unpredictable natural history. Perhaps the greatest barrier to predicting which patients need treatment is our poor understanding of how these tumors cause hearing loss in the first place. In this case-control study, the authors investigated the relationship between preoperative hearing loss and histological changes such as intratumoral microhemorrhage and extensive fibrosis.
From a prospectively collected database, the authors selected all patients with VS who had undergone microsurgical resection as their initial treatment for histopathologically confirmed VS. Histological specimens obtained in 274 of these patients were systematically reviewed by a blinded neuropathologist who graded the extent of microhemorrhage and fibrosis in these tumors. The effect of these variables on preoperative hearing loss was studied using binary logistic regression.
On univariate analysis, patients with extensive intratumoral microhemorrhage or fibrosis (p < 0.0001), patients with larger tumors (p < 0.05), and patients 65 years of age or older (p < 0.05) were significantly more likely to have unserviceable hearing at the time of surgery. On multivariate analysis, only patients with extensive intratumoral microhemorrhage or fibrosis had an increased risk of having unserviceable hearing at the time of surgery (OR 3.72, 95% CI 1.3–10; p = 0.01). Older age and tumor size greater than 3 cm were not statistically significant risk factors for hearing loss, controlling for the effect of microhemorrhage and fibrosis.
In this study, the authors have demonstrated a correlation between the extent of nonneoplastic histological changes, such as microhemorrhage and fibrosis, and hearing loss. This alternate hypothesis has the potential to explain many of the exceptions to previously described mechanisms of hearing loss in patients with VS. The advent of high-resolution MR imaging technology to identify microhemorrhages may provide a method to screen for patients with VS at risk for hearing loss.
2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010