Impact of facility type and volume in low-grade glioma outcomes

The detrimental effect of biopsy preceding resection in surgically accessible glioblastoma: results from the national cancer database

PURPOSE

Aggressive resection in surgically-accessible glioblastoma (GBM) correlates with improved survival over less extensive resections. However, the clinical impact of performing a biopsy before definitive resection have not been previously evaluated.

METHODS

We analyzed 17,334 GBM patients from the NCDB from 2010-2014. We categorized them into: "upfront resection" and "biopsy followed by resection". The outcomes of interes included OS, 30-day readmission/mortality, 90-day mortality, and length of hospital stay (LOS). The Kaplan-Meier methods and accelerated failure time (AFT) models were applied for survival analysis. Multivariable binary logistic regression were performed to compare differences among groups. Multiple imputation and propensity score matching (PSM) were conducted for validation.

RESULTS

"Upfront resection" had superior OS over "biopsy followed by resection" (median OS:12.4 versus 11.1 months, log-rank p = 0.001). Similarly, multivariable AFT models favored "upfront resection" (time ratio[TR]:0.83, 95%CI: 0.75-0.93, p = 0.001). Patients undergoing "upfront gross-total resection (GTR)" had higher OS over "upfront subtotal resection (STR)", "GTR following STR", and "GTR or STR following initial biopsy" (14.4 vs. 10.3, 13.5, 13.3, and 9.1 months;TR: 1.00 [Ref.], 0.75, 0.82, 0.88, and 0.67). Recent years of diagnosis, higher income, facilities located in Southern regions, and treatment at academic facilities were significantly associated with the higher likelihood of undergoing upfront resection. Multivariable regression showed a decreased 30 and 90-day mortality for patients undergoing "upfront resection", 73% and 44%, respectively (p < 0.001).

CONCLUSIONS

Pre-operative biopsies for surgically accessible GBM are associated with worse survival despite subsequent resection compared to patients undergoing upfront resection.

The impact of facility type and volume on treatment and overall survival in craniopharyngioma

BACKGROUND

Craniopharyngiomas are uncommon benign sellar and parasellar tumors with high overall survival (OS) and recurrence rates. Treatment is often surgical but may include adjuvant therapies. The impact of adjuvant therapy and surgical approach have been evaluated, however, facility volume and type have not. The purpose of this study is to analyze the influence of facility volume and type on treatment modalities, extent of surgery and survival of craniopharyngioma.

METHODS

The 2004-2016 National Cancer Database (NCDB) was queried for patients diagnosed with craniopharyngioma. Facilities were classified by type (academic vs. non-academic) and low-volume center (LVC) (Treating < 8 patients over the timeline) versus high-volume center (HVC), (Treating ≥ 8 patients over the timeline). Differences in treatment course, outcomes, and OS by facility type were assessed.

RESULTS

3730 patients (51.3% female) with mean age 41.2 ± 22.0 were included with a 5-year estimated OS of 94.8% (94.0-95.5%). 2564 (68.7%) patients were treated at HVC, of which 2142 (83.5%) were treated at academic facilities. Patients treated at HVC's were more likely to undergo both surgery and radiation. Surgical approach at HVC was more likely to be endoscopic. Patients treated at HVC demonstrated significantly higher 5-year OS compared to patients treated at LVC (96% [95% CI 95.6-97.1% versus 91.2% [95% CI 89-92.7%] with lower risk of mortality (Hazard ratio [95% CI] = 0.69 [0.56-0.84]).

CONCLUSION

Treatment of craniopharyngioma at HVC compared to LVC is associated with improved OS, lower 30- and 90-day postoperative mortality risk, and more common use of both radiotherapy and endoscopic surgical approach.

The Influence of Facility Volume and Type on Skull Base Chordoma Treatment and Outcomes

OBJECTIVE

To evaluate the influence of facility case volume and type on skull base chordoma treatment and overall survival (OS).

METHODS

The 2004-2016 National Cancer Database was queried for skull base chordoma patients receiving definitive treatment. Facilities were categorized into 2 cohorts by calculating the mean number of patients treated per facility and using cutoff numbers that were 0.5 SD above and below the computed mean to separate the groups. As, by definition of the inclusion criteria, all included facilities treated at least 1 patient, low-volume facilities were defined as treating 1 patient, and high-volume facilities were defined as treating ≥7 patients; mid-volume facilities (facilities treating ≥2 but ≤6 patients) were excluded. Differences in treatment course, outcomes, and OS by facility type were assessed.

RESULTS

The study included 658 patients (44.8% female, 79.5% White). The 187 unique facilities were categorized into 95 low-volume facilities (treating 1 patient during timeline) and 26 high-volume facilities (treating ≥7 patients during timeline). Kaplan-Meier log-rank analysis demonstrated a significant positive association between facility volume and OS (P < 0.001) and an improvement in OS in patients at academic facilities (P = 0.018). On Cox proportional hazards multivariate regression after adjusting for sex, age, Charlson-Deyo comorbidity index, and insurance type, high-volume facilities and academic facilities were associated with a lower mortality risk than low-volume facilities and nonacademic facilities (P < 0.001 and P = 0.03, respectively).

CONCLUSIONS

Higher facility case volume and academic facility type appear to be associated with improved survival outcomes in treatment of skull base chordomas.

Pituitary adenoma in the elderly: surgical outcomes and treatment trends in the United States

OBJECTIVE

Decision-making in how to manage pituitary adenomas (PAs) in the elderly (age ≥ 65 years) can be challenging given the benign nature of these tumors and concerns about surgical morbidity in these patients. In this study involving a large multicenter national registry, the authors examined treatment trends and surgical outcomes in elderly compared to nonelderly patients.

METHODS

The National Cancer Data Base (NCDB) was queried for adults aged ≥ 18 years with PA diagnosed by MRI (in observed cases) or pathology (in surgical cases) from 2004 to 2016. Univariate and multivariate logistic regressions were used to evaluate the prognostic impact of age and other covariates on 30- and 90-day postsurgical mortality (30M/90M), prolonged (≥ 5 days) length of inpatient hospital stay (LOS), and extent of resection.

RESULTS

A total of 96,399 cases met the study inclusion criteria, 27% of which were microadenomas and 73% of which were macroadenomas. Among these cases were 25,464 elderly patients with PA. Fifty-three percent of these elderly patients were treated with surgery, 1.9% underwent upfront radiotherapy, and 44.9% were observed without treatment. Factors associated with surgical treatment compared to observation included younger age, higher income, private insurance, higher Charlson-Deyo comorbidity (CD) score, larger tumor size, and receiving treatment at an academic hospital (each p ≤ 0.01). Elderly patients undergoing surgery had increased rates of 30M (1.4% vs 0.6%), 90M (2.8% vs 0.9%), prolonged LOS (26.1% vs 23.0%), and subtotal resection (27.2% vs 24.5%; each p ≤ 0.01) compared to those in nonelderly PA patients. On multivariate analysis, age, tumor size, and CD score were independently associated with worse postsurgical mortality. High-volume facilities (HVFs) had significantly better outcomes than low-volume facilities: 30M (0.9% vs 1.8%, p < 0.001), 90M (2.0% vs 3.5%, p < 0.001), and prolonged LOS (21.8% vs 30.3%, p < 0.001). A systematic literature review composed of 22 studies demonstrated an elderly PA patient mortality rate of 0.7%, which is dramatically lower than real-world NCDB outcomes and speaks to substantial selection bias in the previously published literature.

CONCLUSIONS

The study findings confirm that elderly patients with PA are at higher risk for postoperative mortality than younger patients. Surgical risk in this age group may have been previously underreported in the literature. Resection at HVFs better reflects these historical rates, which has important implications in elderly patients for whom surgery is being considered.

Utility of Administrative Databases and Big Data on Understanding Glioma Treatment—A Systematic Review

Background Gliomas are a heterogeneous group of tumors where large multicenter clinical and genetic studies have become increasingly popular in their understanding. We reviewed and analyzed the findings from large databases in gliomas, seeking to understand clinically relevant information.

Methods A systematic review was performed for gliomas studied using large administrative databases up to January 2020 (e.g., National Inpatient Sample [NIS], National Surgical Quality Improvement Program [NSQIP], and Surveillance, Epidemiology, and End Results Program [SEER], National Cancer Database [NCDB], and others).

Results Out of 390 screened studies, 122 were analyzed. Studies included a wide range of gliomas including low- and high-grade gliomas. The SEER database (n = 83) was the most used database followed by NCDB (n = 28). The most common pathologies included glioblastoma multiforme (GBM) (n = 67), with the next category including mixes of grades II to IV glioma (n = 31). Common study themes involved evaluation of descriptive epidemiological trends, prognostic factors, comparison of different pathologies, and evaluation of outcome trends over time. Persistent health care disparities in patient outcomes were frequently seen depending on race, marital status, insurance status, hospital volume, and location, which did not change over time. Most studies showed improvement in survival because of advances in surgical and adjuvant treatments.

Conclusions This study helps summarize the use of clinical administrative databases in gliomas research, informing on socioeconomic issues, surgical outcomes, and adjuvant treatments over time on a national level. Large databases allow for some study questions that would not be possible with single institution data; however, limitations remain in data curation, analysis, and reporting methods.

Improved outcomes associated with maximal extent of resection for butterfly glioblastoma: insights from institutional and national data

BACKGROUND

Butterfly glioblastomas (bGBMs) are grade IV gliomas that infiltrate the corpus callosum and spread to bilateral cerebral hemispheres. Due to the rarity of cases, there is a dearth of information in existing literature. Herein, we evaluate clinical and genetic characteristics, associated predictors, and survival outcomes in an institutional series and compare them to a national cohort.

METHODS

We identified all adult patients with bGBM treated at Brigham & Women's Hospital (2008-2018). The National Cancer Database (NCDB) was also queried for bGBM patients. Survival was analyzed with Kaplan-Meier methods, and Cox models were built to assess for predictive factors.

RESULTS

Of 993 glioblastoma patients, 62 cases (6.2%) of bGBM were identified. Craniotomy for resection was attempted in 26 patients (41.9%), with a median volumetric extent of resection (vEOR) of 72.3% (95% confidence interval [95%CI] 58.3-82.1). The IDH1 R132H mutation was detected in two patients (3.2%), and MGMT promoter was methylated in 55.5% of the assessed cases. In multivariable regression, factors predictive of longer OS were increased vEOR, MGMT promoter methylation, and receipt of adjuvant therapy. Median OS for the resected cases was 11.5 months (95%CI 7.7-18.8) vs. 6.3 (95%CI 5.1-8.9) for the biopsied. Of 21,353 GBMs, 719 (3.37%) bGBM patients were identified in the NCDB. Resection was more likely to be pursued in recent years, and GTR was independently associated with prolonged OS (p < 0.01).

CONCLUSION

Surgical resection followed by adjuvant chemoradiation is associated with significant survival gains and should be pursued in carefully selected bGBM patients.

Treatment trends and overall survival in patients with grade II/III ependymoma: The role of tumor grade and location

BACKGROUND

Treatment of ependymoma (EPN) is guided by associated tumor features, such as grade and location. However, the relationship between these features with treatments and overall survival in EPN patients remains uncharacterized. Here, we describe the change over time in treatment strategies and identify tumor characteristics that influence treatment and survival in EPN.

METHODS AND MATERIALS

Using the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) 18 Registries (1973-2016) database, we identified patients with EPN microscopically confirmed to be grade II (EPN-GII) or III (EPN-GIII) tumors between 2004-2016. Overall survival (OS) was analyzed using Kaplan-Meier survival estimates and multivariable Cox proportional hazard models. A sub-analysis was performed by tumor location (supratentorial, posterior fossa, and spine). Change over time in rates of gross total resection (GTR), radiotherapy (RT), and chemotherapy (CS) were analyzed using linear regression, and predictors of treatment were identified using multivariable logistic regression models.

RESULTS

Between 2004-2016, 1,671 patients were diagnosed with EPN, of which 1,234 (74 %) were EPN-GII and 437 (26 %) EPN-GIII. Over the study period, EPN-GII patients underwent a less aggressive treatment (48 % vs 27 %, GTR; 60 % vs 30 %, RT; 22 % vs 2%, CS; 2004 vs 2016; p < 0.01 for all). Age, tumor size, location, and grade were positive predictors of undergoing treatment. Univariate analysis revealed that tumor grade and location were significantly associated with OS (p < 0.0001 for both). In multivariable Cox regression, tumor grade was an independent predictor of OS among patients in the cohort (grade III, HR 3.89 [2.84-5.33]; p < 0.0001), with this finding remaining significant across all tumor locations.

CONCLUSIONS

In EPN, tumor grade and location are predictors of treatment and overall survival. These findings support the importance of histologic WHO grade and location in the decision-making for treatment and their role in individualizing treatment for different patient populations.

Association Between Facility Volume and Overall Survival for Patients with Grade II Meningioma after Gross Total Resection

BACKGROUND

The role of adjuvant radiation after gross total resection (GTR) for grade II meningioma is evolving, prompting further evaluation in NRG-BN003, a phase 3 national trial. Furthermore, the relationship between facility volume and outcomes in patients with grade II meningioma after GTR has not been examined at a national level. We aim to assess overall survival (OS) of patients with grade II meningioma after GTR by surgical case volume and OS by receipt of adjuvant radiation.

METHODS

We used the National Cancer Database to identity 2823 patients diagnosed with grade II meningioma who underwent GTR. Propensity score matching was applied to balance covariates in patients with grade II meningioma after GTR stratified by adjuvant radiation status. Multivariable logistic regression was used to assess factors associated with radiation receipt. Kaplan-Meier and log-rank tests were used to assess OS by facility volume.

RESULTS

As facility volume increased, OS increased, with a 5-year OS of 72.8% for facilities with GTR grade II meningioma volumes of ≤8 cases per decade and 87.5% for >8 cases per decade (P < 0.0001). There was no difference in 5-year OS between GTR alone and GTR with adjuvant radiation (84.8% vs. 86.4%; P = 0.151). Covariates significantly associated with radiation receipt included facility location, facility volume, distance, and tumor size.

CONCLUSIONS

Treatment at higher surgical case volume facilities is associated with improved OS for GTR grade II meningioma. These facilities also have more patients receiving adjuvant radiation. However, we observed no difference in OS between adjuvant radiation and surgery alone.

The association between facility volume and overall survival in patients with Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma is an uncommon malignancy often requiring multidisciplinary management. The purpose of this study was to determine whether high-volume facilities have improved outcomes in patients with Merkel cell carcinoma relative to lower-volume facilities.

METHODS

A total of 5304 patients from the National Cancer Database with stage I-III Merkel cell carcinoma undergoing surgery were analyzed. High-volume facilities were the top 1% by case volume. Multivariable Cox regression and propensity score-matching were performed to account for imbalances between groups.

RESULTS

Treatment at high-volume facilities (hazard ratio: 0.74; 95% confidence interval: 0.65-0.84, P < .001) was independently associated with improved overall survival (OS) in multivariable analyses. In propensity score-matched cohorts, 5-year OS was 62.3% at high-volume facilities vs 56.8% at lower-volume facilities (P < .001). Median OS was 111 months at high-volume facilities vs 79 months at lower-volume facilities.

CONCLUSION

Treatment at high-volume facilities is associated with improved OS in Merkel cell carcinoma. Given the impracticality of referring all elderly patients with Merkel cell carcinoma to a small number of facilities, methods to mitigate this disparity should be explored.

Failure to complete standard radiation therapy in glioblastoma patients: Patterns from a national database with implications for survival and therapeutic decision making in older glioblastoma patients

INTRODUCTION

It is estimated that 5%-10% of patients with newly diagnosed glioblastoma (GBM) fail to complete standard chemoradiation (CRT). We sought to determine the impact of failure to complete CRT on survival and to identify risk factors.

METHODS

We queried the National Cancer Database and identified a cohort of 17,451 adults with GBM diagnosed from 2005 to 2012. The cohort was restricted to patients that started conventionally fractionated adjuvant chemoradiation of 1.8 to 2.0 Gy per fraction to a dose of ≤66Gy. Patients were stratified by RT dose: a) completed RT ≥ 58Gy, b) nearly completed RT ≥ 50Gy - <58Gy, and c) did not complete RT ≤ 50Gy.

RESULTS

The CRT completion rate correlated with survival, 87% of patients completed CRT and had a median OS of 13.5 months, 4% were near completers (median OS 5.7 months), and 9% did not complete RT (median OS 1.9 months). Older age was associated with a higher risk of non-completion. Twenty-eight percent of patients ≥80 years old did not complete standard CRT (OR 2.99) and 19% of 70-79-year olds did not complete CRT (OR 1.99). The adjusted mortality hazard ratio was greater for patients that did not complete CRT across all age categories and for nearly complete CRT patients older than 40 (non-significant for age < 40).

CONCLUSIONS

Failure to complete standard chemoradiation was associated with decreased survival in our cohort. Patients with risk factors for failure (like advanced age) should be considered for alternative treatments such as hypofractionated radiotherapy.