Genetic association between atopic disease and osteoarthritis

OBJECTIVES

To evaluate the association between genetically determined risk for atopic disease and osteoarthritis (OA).

METHODS

We performed linkage disequilibrium (LD) score regression using 1000 Genomes Project European samples as a reference for patterns of genome-wide LD. Summary statistics for atopic disease traits were obtained from the UK Biobank. We generated a pairwise genetic correlation between OA and traits for atopic disease to estimate the genetic correlation between traits (rg) and heritability for each trait. The association between atopy-related traits and OA was examined using Mendelian randomization (MR) on summary statistics; we reported inverse-variance weighted (IVW), MR-Egger, maximum likelihood estimation, weighted median, and weighted mode.

RESULTS

There was a significant positive correlation between the genome-wide genetic architecture of asthma and all OA traits. Using the IVW (random effects), there was a significant association between asthma and knee OA ((odds ratio) OR = 1.04, 95% (confidence interval) CI 1.01-1.08, p = 0.0169). Using IVW (fixed effects), significant associations were identified between knee OA and allergic disease (OR = 1.07, 95% CI 1.01-1.14, p = 0.0342), allergic rhinitis (OR = 1.07, 95% CI 1.00-1.13, p = 0.0368), and asthma (OR = 1.04, 95% CI 1.01-1.07, p = 0.0139), as well as for OA at any site and asthma (OR = 1.02, 95% CI 1.00-1.04, p = 0.0166).

CONCLUSIONS

We found a significant correlation between the overall genetic architecture of asthma and OA, as well as an increased risk of developing OA in patients with genetic variants associated with asthma and allergic rhinitis; predominately, this risk was for the development of knee OA. These results support a causal relationship between asthma and/or allergic rhinitis and knee OA.

EPID-20. MORTALITY TRENDS IN PRIMARY MALIGNANT BRAIN AND CENTRAL NERVOUS SYSTEM TUMORS VARY BY HISTOPATHOLOGY, AGE, RACE, AND SEX

BACKGROUND

Primary malignant brain and other central nervous system tumors (BT) are rare cancers that have shown rising mortality rates in recent years. To elucidate potential factors involved in this rising death rate, we examined mortality trends for primary malignant BT in the United States (US) stratified by histopathology groupings, age, race, and sex.

METHODS

Mortality rates for demographic factors within primary malignant BT were generated using the Center for Disease Control’s National Vital Statistics Systems (NVSS) data from 2004 to 2018. Additionally, histopathology-specific incidence-based mortality rates were calculated using the National Cancer Institute’s Surveillance, Epidemiology, and End-Results (SEER) 18 data from 2004 to 2018. Joinpoint modeling was used to estimate mortality trends and annual percent changes (APC) with corresponding 95% confidence intervals (CI).

RESULTS

Overall, there was a very small increase in mortality from 2004-2018 (NVSS, APC: 0.3%, 95% CI: 0.1%-0.5%). Individuals 65+ years of age saw a small increase in mortality (NVSS, APC: 0.6%, 95% CI: 0.4%-0.9%), while changes in individuals of other ages were non-significant. Asian/Pacific Islander or American Indian/Alaskan Native had the largest increase in mortality (NVSS, APC: 1.6%, 95% CI: 0.7%-2.4%). Overall mortality trends by sex were similar. Among histopathology groupings, there was a small mortality increase in adults ages 65+ years with glioblastoma (SEER, APC: 0.5%, 95% CI: 0.1%-1.0%), while patients with other glioma and non-glioma did not show significant changes in mortality. In pediatric patients (ages 0-14 years), high-grade glioma mortality increased significantly from 2004-2015 (SEER, APC: 7.0%, 95% CI: 3.8%-10.3%) but had a non-significant decrease from 2015-2018. Pediatric patients with embryonal tumors had a significant mortality decrease between 2004 and 2018 (SEER, APC: -1.9%, 95% CI: -3.3%-0.5%).

CONCLUSION

Examining age, race, sex, and histopathology-specific mortality at the population level can provide important information for clinicians, researchers, and aid in public health planning.

BIOM-23. MOLECULAR MARKER TESTING AND REPORTING COMPLETENESS FOR ADULT-TYPE DIFFUSE GLIOMAS IN THE UNITED STATES

BACKGROUND

A newly developed brain molecular marker (BMM) data item was implemented by U.S. cancer registries for individuals diagnosed with brain tumors in 2018—including IDH and 1p/19q-codeletion statuses for adult-type diffuse gliomas. We thus investigated the testing/reporting completeness of BMM in the U.S.

METHODS

Cases of histopathologically-confirmed glioblastoma, astrocytoma, and oligodendroglioma diagnosed in 2018 were identified in the National Cancer Database. Adjusted odds ratios (ORadj) and 95% confidence intervals (95CI) of BMM testing/reporting were evaluated for association with selected patient, treatment, and facility-level characteristics using multivariable logistic regression. As a secondary analysis, predictors of MGMT promoter methylation testing/reporting among IDH-wildtype glioblastoma individuals was assessed.

RESULTS

Among 7,370 histopathologically-diagnosed adult-type diffuse gliomas nationally, the overall BMM testing/reporting completeness was 81%. Compared to biopsy-only cases, the odds of testing/reporting increased for increased for subtotal (ORadj= 1.38 [95CI: 1.19-1.61], p< 0.001) and gross total resection (ORadj=1.53 [95CI: 1.33-1.77], p< 0.001). Furthermore, the odds of testing/reporting completeness were lowest at community centers (hospitals (65.8%; ORadj=0.33 [95CI: 0.24-0.44], p< 0.001) and highest at academic/NCI-designated comprehensive cancer centers (85.3%; referent). By geographical location, BMM testing/reporting completeness ranged from a high of 86.9% at New England (referent) to a low of 75.2% in the West South Central region (ORadj=0.55 [95CI: 0.39-0.76]; p< 0.001). Extent of resection, facility type, and facility location were additionally significant predictors of MGMT testing/reporting among IDH-wildtype glioblastoma cases.

CONCLUSION

Initial BMM testing/reporting completeness for individuals with adult-type diffuse gliomas in the U.S. were favorable, although patterns varied by hospital attributes and extent of resection.

EPID-19. CHANGES IN SURVIVAL OVER TIME FOR ALL PRIMARY BRAIN AND OTHER CNS TUMORS IN THE UNITED STATES

BACKGROUND

Despite advances in cancer diagnosis and clinical care, survival for many primary brain and other central nervous system (CNS) tumors remain poor. This study performs a comprehensive survival analysis on these tumors.

METHODS

Survival differences were determined utilizing the National Program of Cancer Registries Survival Analytic file for all primary brain and other CNS tumors. Overall survival and survival of the 5 most common histopathologies within specific age groups (children ages 0-14 years, adolescents, and young adults [AYA] ages 15-39 years, and older adults ages 40+ years) were determined. Overall survival was compared for three time periods: 2004-2007, 2008-2012, and 2013-2017. Kaplan-Meier and multivariable Cox proportional hazards models were used to generate median survival, hazard ratios (HR) and 95% confidence intervals (CI). Models were adjusted for sex, race/ethnicity, and treatment pattern. Malignant and non-malignant brain tumors were assessed separately.

RESULTS

Aside from hemangioma and mesenchymal tumors in older adults, no notable changes in survival were observed across the time periods for non-malignant tumors. For malignant brain tumors, significant survival improvements were observed in children with embryonal tumors (logrank p = 0.00028) and in AYA with anaplastic astrocytoma (logrank p = 0.0043). In older adults, significant improvement was observed in the five most common histopathologies except oligodendroglioma. Adjusted for sex, race/ethnicity, and treatment, there were improvements in survival in 2008-2012 and 2013-2017, when compared to 2004-2007, in children and AYA with malignant tumors (Children: HR = 0.92, 95% CI = 0.87-0.98, p = 0.010 in 2008-2012; HR = 0.91, 95% CI = 0.85-0.97, p = 0.005 in 2013-2017; AYA: HR = 0.92, 95% CI = 0.88-0.96, p < 0.001, in 2008-2012; HR = 0.87, 95% CI = 0.83-0.93, p < 0.001 in 2013-2017).

CONCLUSIONS

Overall survival for malignant brain and other CNS tumors improved slightly in 2013-2017 for all age groups as compared to 2004-2007. No significant changes were observed for non-malignant brain and other CNS tumors.

EPID-06. IMPROVEMENTS IN SURVIVAL FOR GLIOBLASTOMA IN THE POST-STUPP PROTOCOL ERA

BACKGROUND

Introduction of the Stupp protocol for glioblastoma treatment in 2005 led to a significant increase in overall survival in glioblastoma. Prior analyses identified additional survival gains in glioblastoma since this time, though the source of these gains is unknown. In this analysis, we leveraged commercial claims and population-based datasets to better understand potential treatment factors associated with improved survival for glioblastoma.

METHODS

Provider-side commercial claims data were obtained from IQVIA for adults (18+) diagnosed with malignant brain tumor (ICD-9 codes: 191.0-191.9 or ICD-10 codes: C71.0-C71.9) from 2013-2021. Glioblastoma patients were identified as those who received biopsy/resection, radiation and temozolomide within 60 days of their brain tumor diagnosis. Treatment patterns were determined using ICD-9/ICD-10 procedure codes and HCPCS/CPT codes. Date of death was determined by a claim containing the CPT codes 99238 or 99239 or date of last claim followed by at least 30 days of no additional claims. Population-based survival data for microscopically-confirmed adult glioblastoma cases receiving radiation treatment from the National Program of Cancer Registries (NPCR) from 2004-2018 were used as a comparison group. Median survival was estimated using Kaplan-Meier regression, overall in IQVIA and by two-year periods in NPCR.

RESULTS

In the IQVIA cohort, 9,368 individuals (2.5%) were identified as glioblastoma based on treatment criteria. Median survival in the IQVIA cohort 16.6 months (15.2-17.0), and 12 months (95%CI:12-12) in NPCR. Median survival in NPCR increased from 11 months in 2004-2006, to 12 months in 2006-2009, and then 13 months in 2010-2018. Within the IQVIA cohort, 27% had ≥ 1 claim for Bevacizumab and 15% had ≥ 1 claim for tumor treating fields.

CONCLUSIONS

Survival in glioblastoma continues to improve over time, which may be due to developments of new therapeutic approaches. Assessment of population-level survival patterns is essential for understanding the impact of treatment advancements in the general population.

EPID-11. NATIONAL EPIDEMIOLOGY AND SURVIVAL OF ADULT-TYPE DIFFUSE GLIOMAS IN THE UNITED STATES BY IDH, 1P/19Q, MGMT, AND WHO CNS GRADE

BACKGROUND

Histomolecularly-defined adult-type diffuse gliomas—including IDH-wildtype glioblastoma, IDH-mutant astrocytoma, and IDH-mutant 1p/19q-codeleted oligodendroglioma—were incorporated into U.S. cancer registry reporting for individuals with brain tumors beginning in 2018. We therefore assessed their epidemiology and overall survival (OS) patterns.

METHODS

Individuals histopathologically diagnosed with diffuse gliomas in 2018 and had brain molecular marker data were identified within the National Cancer Database; Surveillance, Epidemiology, and End Results Incidence; and Central Brain Tumor Registry of the United States databases. Age-adjusted incidence rates per 100,000 population with 95% confidence intervals (95CI) were estimated. OS was estimated using Kaplan Meier methods and stratified by WHO CNS grade, age, sex, tumor size, treatment, extent of resection, and MGMT promoter methylation. WHO CNS grade was additionally examined among individuals with IDH-wildtype diffuse astrocytic gliomas.

RESULTS

IDH-wildtype glioblastomas’ incidence rate was 1.74 (95CI = 1.69-1.78); as compared to 0.14 (95CI = 0.12-0.15), 0.15 (95CI = 0.14-0.16), and 0.07 (95CI: 0.06-0.08) WHO grade 2, 3, and 4 IDH-mutant astrocytomas. Irrespective of grade, IDH mutation prevalence was highest in adolescents & young adults, and IDH-mutant astrocytomas were more frequently MGMT promoter methylated. For OS analysis, 8,651 individuals were identified: one-year OS was 53.7% for WHO grade 4 IDH-wildtype glioblastomas (95CI = 52.5-54.9); 98.0% (95CI = 96.1-99.0), 92.4% (95CI = 89.6-94.5), and 76.3% (95CI = 70.1-81.3) for grade 2, 3, and 4 IDH-mutant astrocytomas; 97.9% (95CI = 95.9-98.9) and 94.4% (95CI = 90.9-96.6) for grade 2 and 3 IDH-mutant 1p/19q-codeleted oligodendrogliomas. Among IDH-wildtype glioblastomas, median OS was 17.1 months (95CI = 16.1-18.6) and 12.4 months (95CI = 12.0-12.9) for methylated and unmethylated MGMT promoters. IDH-wildtype diffuse astrocytic gliomas reported as WHO grade 2 or 3 demonstrated longer adjusted OS compared to grade 4 tumors (both p < 0.001). A significant association was not observed between chemotherapy and OS (HRadjusted 0.95, 95CI = 0.41-2.22, p = 0.91) for radiotherapy-treated grade 3 IDH-wildtype diffuse astrocytic gliomas.

CONCLUSIONS

Our findings provide the initial U.S. epidemiological estimates for histomolecularly-defined adult-type diffuse gliomas.

Epidemiology of primary malignant non-osseous spinal tumors in the United States

BACKGROUND CONTEXT

Primary malignant non-osseous spinal tumors are relatively rare and this has led to a paucity of studies specifically examining the epidemiology of malignant spinal tumors.

PURPOSE

To provide an updated and more comprehensive study examining the epidemiology and relative survival of these rare tumors.

STUDY DESIGN/SETTING

Data was retrospectively acquired from the Central Brain Tumor Registry of the United States (CBTRUS).

PATIENT SAMPLE

Primary malignant non-osseous spinal tumor cases diagnosed between 2000 and 2017 in the United States.

OUTCOME MEASURES

Incidence rates (IRs), relative survival rates, and hazard ratios (HR) were measured.

METHODS

IRs were calculated only for histologically-confirmed cases between 2000 and 2017. Relative survival estimates were calculated from survival information on malignant spinal tumors between 2001 and 2016 for death from any cause. Multivariable Cox proportional hazards regression models were constructed to control for age, sex, race, and ethnicity.

RESULTS

From 2000 to 2017, approximately 587 new cases of malignant non-osseous spinal tumors were diagnosed every year in the United States. The overall IR was 0.178 per 100,000 persons. Ependymomas were the most commonly diagnosed tumor in all age groups. The 10-year relative survival rates were 94.1%, 62.1%, 62.0%, and 13.3% for ependymomas, lymphomas, diffuse astrocytomas, and high-grade astrocytomas, respectively. Females have a significantly lower risk of death as compared with males for ependymomas (HR: 0.74, p<.001) and diffuse astrocytomas (HR: 0.70, p=.005). African-Americans have a significantly higher risk of death compared with Caucasians when diagnosed with ependymomas (HR: 1.52, p=.009) or lymphomas (HR: 1.55, p=.009).

CONCLUSION

Primary malignant non-osseous spinal tumors are primarily diagnosed in adulthood or late adulthood. Ependymal tumors are the most commonly diagnosed primary malignant non-osseous spinal tumors and have the highest 10-year relative survival rates. High-grade astrocytomas are rare and portend the worst prognosis.

EPID-05. A novel, clinically-relevant classification of pediatric CNS tumors for cancer registries using a clustering analysis

To accurately evaluate the burden of pediatric central nervous system (CNS) tumors, estimate resources for cancer control, and monitor outcomes, a classification system that segregates tumors into clinically relevant groups is essential. The current classification of CNS tumors included in the third revision of the International Childhood Cancer Classification does not identify key clinical groups, such as low- and high-grade gliomas. To address this need, a novel classification was embarked upon using ICD-O-3 codes, CBTRUS grouping, incidence, survival, and treatment modalities as inputs. For each ICD-O-3 code with &gt;50 new cases/year in CBTRUS from 2000 to 2016, 2 clinicians reached consensus defining the efficacy of three treatment modalities: surgical resection, radiotherapy, and chemotherapy. Then, patient level 5-year overall survival (OS) times were simulated based on total incidence and 5-year OS for each code. Subsequently, 5 factors were included as potential classifiers: tumor behavior, CBTRUS sub-group, and efficacy of the three treatment modalities. A “survival tree” was developed by using partitioning. Starting with the patient cohort (root), univariate cox proportional hazards model was used to identify statistically significant (P &lt; 0.05) factors. The factors with the largest hazard ratio were selected manually to create child nodes. Within each child node, the partitioning process was repeated on remaining factors until no statistically significant factor remained. This clustering yielded 4 main groups (low-, intermediate-, high-, and very high-risk tumors) and 11 subgroups, including “embryonal tumors” and “low-risk glial and glioneuronal tumors”. Further validation of the classification will be sought through a structured consensus process using multidisciplinary experts. This systematic method to develop a classification for pediatric CNS tumors will allow for more relevant estimations of outcomes and better estimation of resource utilization. Furthermore, this strategy could be replicated for other disease groups.

A population study of clinical trial accrual for women and minorities in neuro-oncology following the NIH Revitalization Act

BACKGROUND

The NIH Revitalization Act, implemented 29 years ago, set to improve the representation of women and minorities in clinical trials. In this study, we investigate progress made in all phase therapeutic clinical trials for neuroepithelial CNS tumors stratified by demographic-specific age-adjusted disease incidence and mortality. Additionally, we identify workforce characteristics associated with clinical trials meeting established accrual benchmarks.

METHODS

Registry study of published clinical trials for World Health Organization defined neuroepithelial CNS tumors between January 2000 and December 2019. Study participants were obtained from PubMed and ClinicalTrials.gov. Population-based data originated from the CBTRUS for incidence analyses. SEER-18 Incidence-Based Mortality data was used for mortality analysis. Descriptive statistics, Fisher exact, and χ 2 tests were used for data analysis.

RESULTS

Among 662 published clinical trials representing 49 907 participants, 62.5% of participants were men and 37.5% women (P < .0001) representing a mortality specific over-accrual for men (P = .001). Whites, Asians, Blacks, and Hispanics represented 91.7%, 1.5%, 2.6%, and 1.7% of trial participants. Compared with mortality, Blacks (47% of expected mortality, P = .008), Hispanics (17% of expected mortality, P < .001) and Asians (33% of expected mortality, P < .001) were underrepresented compared with Whites (114% of expected mortality, P < .001). Clinical trials meeting accrual benchmarks for race included minority authorship.

CONCLUSIONS

Following the Revitalization Act, minorities and women remain underrepresented in therapeutic clinical trials for neuroepithelial tumors, relative to disease incidence and mortality. Study accrual has improved with time. This study provides a framework for clinical trial accrual efforts and offers guidance regarding workforce considerations associated with enrollment of underserved patients.

The Central Brain Tumor Registry of the United States Histopathological Grouping Scheme Provides Clinically Relevant Brain and Other Central Nervous System Categories for Cancer Registry Data

Background

Brain and other central nervous system (CNS) tumors are a heterogenous collection of tumors, but they are generally reported in local and national cancer statistics as a single, large category. Although the collection of non-malignant brain and other CNS tumors has been mandated since diagnosis year 2004, these tumors are often excluded from standard statistical reports on cancer despite their burden on populations in the United States and Canada. The Central Brain Tumor Registry of the United States (CBTRUS) historical and current histopathological grouping schemes have been developed in collaboration with neuropathologists to capture the diversity of these tumors in clinically relevant categories. The goal of this analysis was to test a new recode variable based on the CBTRUS histopathology grouping prior to releasing the variable for use in the North American Association of Central Cancer Registries (NAACCR) Cancer in North American (CiNA) data sets and by individual cancer registries.

Methods

The CBTRUS histopathology grouping scheme variable was created and implemented in an evaluation CiNA data set. The accuracy of the variable's categories was evaluated. Counts and incidence rates were calculated using SEER*Stat.

Results

Overall, 481,650 cases of brain and other CNS tumors meeting the CBTRUS definition were identified for diagnosis years 2015-2019 in the CiNA data set for the US and Canada, making these the sixth-most-common tumor as a group. Of the brain and other CNS tumor cases, approximately 29% were malignant (behavior code /3 in the International Classification of Diseases for Oncology, 3rd edition [ICD-O-3]) while about 71% were nonmalignant (ICD-O-3 behavior code /0 or /1). The overall age-adjusted annual incidence rate (AAAIR) of brain and other CNS tumors was 24.44 per 100,000 (95% CI, 24.37-24.51). The most common histopathologies were meningioma, of which approximately 99% were nonmalignant (AAAIR, 9.09 per 100,000; 95% CI, 9.05-9.13); tumors of the pituitary, of which about 99% were nonmalignant (AAAIR, 4.28 per 100,000; 95% CI, 4.25-4.31); and glioblastoma, of which 100% were malignant behavior (AAAIR, 3.20 per 100,000; 95% CI, 3.18-3.22).

Conclusion

Brain and other CNS tumors make up an extremely diverse category that contributes substantially to the cancer burden in North America. The CBTRUS histopathology grouping variable provides clinically relevant groupings for analysis of these tumors in the NAACCR CiNA as well as by individual central cancer registry groups. We encourage the use of this variable to support more detailed analysis of this important group of tumors.

EPID-26. ALIGNING THE CBTRUS HISTOLOGY GROUPS WITH 2016 WHO CLASSIFICATION OF TUMORS OF THE CENTRAL NERVOUS SYSTEM

BACKGROUND

The Central Brain Tumor Registry of the United States (CBTRUS) uses a histology grouping scheme modeled after the World Health Organization (WHO) Classification of Tumours of the Central Nervous System (CNS) to classify cancer registry records for clinically relevant statistical reporting. Molecular studies have identified genetic features which precisely stratify tumor types, resulting in the 2016 update to the WHO Classification incorporating these markers. To continue providing clinically relevant statistics, the histology groupings have been aligned with the 2016 update. Resulting changes to groupings were assessed.

METHODS

In collaboration with four consulting neuropathologists the scheme was reviewed and realigned to the 2016 update. Obsolete histology nomenclature and ICD-O-3 codes were identified. Evaluation of the frequency of affected codes in the 2013-2017 data was conducted.

RESULTS

417,767 total cases of primary brain and CNS tumors were diagnosed during 2013-2017 in the US. After review of the CBTRUS grouping scheme, 67 codes were noted to be obsolete, 51 codes were re-classified and 12 new codes were incorporated. This reorganization could result in grouping assignment or reporting changes for 2,588 cases (0.6%). The histology groups most significantly affected were mesenchymal tumors and neuronal and mixed neuronal glial tumors.

CONCLUSIONS

The 2016 revision to WHO Classification has affected collection and reporting of CNS tumors. The CBTRUS data edits program is now undergoing revision, which will become the basis of reporting. Some histology-specific molecular markers require additional data to distinguish between cases. In collaboration with CBTRUS, the NAACCR SSDI Committee developed a new variable for collection of molecular information. This variable was included in Uniform Data Standards beginning on January 1, 2018 and will be available for reporting in 2021. A 2021 update to the WHO Classification is scheduled for release later this year, requiring further classification updates.

EPID-09. VARIATION IN GLIOMA INCIDENCE AMONG US HISPANICS BY GEOGRAPHIC REGION OF ORIGIN

BACKGROUND

Glioma incidence is 25% lower in U.S. Hispanics than in White non-Hispanics. The US Hispanic population is diverse and registry-based analyses may mask incidence differences associated with geographic/ancestral origins.

METHODS

County-level glioma incidence data in U.S. Hispanics were retrieved from the Central Brain Tumor Registry of the United States (CBTRUS), which includes data from the Centers for Disease Control’s National Program of Cancer Registries and the National Cancer Institute’s Surveillance, Epidemiology, and End Results program and covers ~100% of the U.S. population. American Community Survey (ACS) data were used to determine county-level proportion of the Hispanic population of Mexican/Central American origin, Caribbean origin (Puerto Rican, Cuban, Dominican), or other origin. Incidence rate ratios (IRRs) were generated to assess the association of glioma incidence in Hispanics with predominant origin group.

RESULTS

Compared to Hispanics living in predominantly Caribbean-origin counties, Hispanics in predominantly Mexican/Central American-origin counties were at lower age-adjusted risk of glioma (IRR=0.83; P&lt; 0.0001), glioblastoma (IRR=0.86; P&lt; 0.0001), diffuse and anaplastic astrocytoma (IRR=0.78; P&lt; 0.0001), oligodendroglioma (IRR=0.82; P&lt; 0.0001), ependymoma (IRR=0.88; P=0.0121), and pilocytic astrocytoma (IRR=0.76; P&lt; 0.0001). Associations were consistent in children and adults, and when using more granular regions of origin. However, Central American origin was associated with modestly increased incidence of several lower-grade glioma histologies. Associations were only partially attenuated after adjusting for state-level estimated of European admixture in Hispanics using 23andMe data.

CONCLUSIONS

Glioma incidence in U.S. Hispanics differs significantly in association with the geographic origins of the Hispanic community, with those of Mexican/Central American origin at significantly reduced risk relative to those of Caribbean origin. U.S. Hispanics are culturally, socioeconomically, and genetically diverse. Although classified as a single ethnic group in most registry data, more granular analytic approaches could advance cancer epidemiology and disparities research.

EPID-08. IMPORTANCE OF THE INTERSECTION OF AGE AND SEX TO UNDERSTAND VARIATION IN INCIDENCE AND SURVIVAL FOR PRIMARY MALIGNANT GLIOMAS

BACKGROUND

Gliomas are the most common type of malignant brain and other CNS tumors, accounting for 80.8% of malignant primary brain and CNS tumors. They cause significant morbidity and mortality. This study investigates the intersection between age and sex to better understand variation of incidence and survival for glioma in the United States.

METHODS

Incidence data from 2000-2017 were obtained from the Central Crain Tumor Registry of the United States, which obtains data from the CDC’s National Program of Cancer Registries and NCI’s Surveillance Epidemiology and End Results Program (SEER), and survival data from the CDC’s NPCR Registries. Age-adjusted incidence rates and rate ratios per 100,000 were generated to compare male-to-female incidence by age group. Cox proportional hazard models were performed by age group, generating hazard ratios to assess male-to-female survival differences.

RESULTS

Overall, glioma incidence was higher in males. Male-to-female incidence was lowest in ages 0-9 years (IRR: 1.04, 95% CI:1.01 - 1.07, p=0.003), increasing with age, peaking at 50-59 years (IRR:1.56, 95% CI: 1.53 - 1.59, p&lt; 0.001). Females had worse survival for ages 0-9 (HR:0.93, 95% CI:0.87-0.99), though male survival was worse for all other age groups, with the difference highest in those 20-29 years (HR:1.36, 95% CI:1.28-1.44). Incidence and survival differences by age and sex also varied by histological subtype of glioma.

CONCLUSION

To better understand the variation in glioma incidence and survival, investigating the intersection of age and sex is key. The current work shows that the combined impact of these variables is dependent on glioma subtype. These results contribute to the growing understanding of sex and age differences that impact cancer incidence and survival.

EPID-06. ASSOCIATIONS BETWEEN GERMLINE GENETIC VARIANTS AND OVERALL SURVIVAL IN PATIENTS WITH GLIOMA

BACKGROUND

In addition to somatic genetic variation in tumors, germline genetic variation can better define cancer susceptibility risk, guide therapy, and predict survival. Most prior research into associations between germline genetic variants and survival outcomes in patients with glioma has been limited by small sample sizes and to high-grade glioma only. This study is the first to use data from Brigham and Women’s Hospital (BWH) and to include both low-grade and high-grade glioma cases to explore associations between germline genetic variants and overall survival.

METHODS

This study included 211 patients enrolled at BWH from April 2010 to January 2020. Ninety-two candidate germline genetic variants were identified via literature review. Fifty-five variants with minor allele frequency &gt;0.05 were included preliminarily, for which bivariate Cox proportional hazards regression models were employed. Twenty-two variants with P&lt; 0.5 were included in the final multivariable model, adjusted for patient sex, age, race, and glioma grade. Stratified sub-analyses were also conducted by sex. Associations were considered statistically significant at P&lt; 0.05.

RESULTS

Among all patients, homozygous C/C genotype at rs17655 (ERCC5 gene) was significantly associated with worse overall survival (hazard ratio=2.61, P=0.0095). Among females only, worse survival was associated with homozygous T/T genotype at rs1381057 (POLQ, hazard ratio=2.58, P=0.046). Among males only, heterozygous status for the A genotype at rs487848 (POLQ, hazard ratio=0.31, P=0.018) and the A genotype at rs1468923 variant (PIK3CA, hazard ratio=0.51, P=0.016) were associated with improved survival.

CONCLUSION

We identified statistically significant associations between overall survival and four variants in genes involved in DNA repair and the PIK3 pathway, three of which were sex-specific. Our results contribute to improving patient stratification in glioma and may lead to increased targeting of treatment strategies.

EPID-11. A POPULATION STUDY OF CLINICAL TRIAL ACCRUAL FOR WOMEN AND MINORITIES IN NEURO-ONCOLOGY FOLLOWING THE NIH REVITALIZATION ACT

INTRODUCTION

The NIH Revitalization Act, implemented 29 years ago, set to improve the representation of women and minorities in clinical trials. In this study, we investigate the progress made in neuro-oncology in all phase therapeutic clinical trials for neuro-epithelial central nervous system tumors in comparison to their demographic-specific age-adjusted disease incidence and mortality.

METHODS

Registry study of all published clinical trials for World Health Organization (WHO) defined neuro-epithelial CNS tumors between January 2000 and December 2019. Study participants for trials were obtained from PubMed and ClinicalTrials.gov. Population-based data from the CBTRUS for incidence analyses. SEER-18 Incidence-Based Mortality data was used for mortality analysis. Descriptive statistics, Fisher exact, and c2 tests were used to analyze the data.

RESULTS

Among 662 published clinical trial articles representing 49, 907 accrued participants, 62.5% of study participants were men and 37.5% were women (P&lt; 0.0001) representing a mortality specific over-accrual for men (P= 0.001) and under-accrual for women (P= 0.001). Whites, Asians, Blacks, and Hispanics represented 91.7%, 1.5%, 2.6%, and 1.7% of trial participants. Compared with their US cancer mortality, Blacks (47% of expected mortality, P=.008), Hispanics (17% of expected mortality, P&lt; .001) and Asians (33% of expected mortality, P&lt; .001) were underrepresented compared with Whites (114% of expected mortality, P&lt; .001).

CONCLUSIONS

Nearly 30 years since the Revitalization Act, minorities and women are consistently underrepresented when compared with their demographic-specific incidence and mortality in therapeutic clinical trials for neuroepithelial tumors. This study provides a framework for investigating cancer clinical trial accrual and offers guidance regarding workforce factors associated with enrollment of vulnerable patients.

Brain tumor biomarkers for research, clinics, and registries - The 2021 Brain Tumor Epidemiology Consortium meeting report

The Brain Tumor Epidemiology Consortium (BTEC) is an international consortium that fosters interdisciplinary collaborations focusing on research related to the etiology, outcomes, and prevention of brain tumors. The 21st annual BTEC meeting with the theme "Brain Tumor Biomarkers for Research, Clinics, and Registries" was held virtually from June 22 to 24, 2021. Scientists from North America and Europe, representing a broad range of brain tumor research interests, presented recent research and progress in the field. The meeting content is summarized in the following report.

Importance of the intersection of age and sex to understand variation in incidence and survival for primary malignant gliomas

Background

Gliomas are the most common type of malignant brain and other CNS tumors, accounting for 80.8% of malignant primary brain and CNS tumors. They cause significant morbidity and mortality. This study investigates the intersection between age and sex to better understand variation of incidence and survival for glioma in the United States.

Methods

Incidence data from 2000 to 2017 were obtained from CBTRUS, which obtains data from the NPCR and SEER, and survival data from the CDC’s NPCR. Age-adjusted incidence rate ratios (IRR) per 100 000 were generated to compare male-to-female incidence by age group. Cox proportional hazard models were performed by age group, generating hazard ratios to assess male-to-female survival differences.

Results

Overall, glioma incidence was higher in males. Male-to-female incidence was lowest in ages 0-9 years (IRR: 1.04, 95% CI: 1.01-1.07, P = .003), increasing with age, peaking at 50-59 years (IRR: 1.56, 95% CI: 1.53-1.59, P < .001). Females had worse survival for ages 0-9 (HR: 0.93, 95% CI: 0.87-0.99), though male survival was worse for all other age groups, with the difference highest in those 20-29 years (HR: 1.36, 95% CI: 1.28-1.44). Incidence and survival differences by age and sex also varied by histological subtype of glioma.

Conclusions

To better understand the variation in glioma incidence and survival, investigating the intersection of age and sex is key. The current work shows that the combined impact of these variables is dependent on glioma subtype. These results contribute to the growing understanding of sex and age differences that impact cancer incidence and survival.

Association of Maximal Extent of Resection of Contrast-Enhanced and Non-Contrast-Enhanced Tumor With Survival Within Molecular Subgroups of Patients With Newly Diagnosed Glioblastoma

Importance

Per the World Health Organization 2016 integrative classification, newly diagnosed glioblastomas are separated into isocitrate dehydrogenase gene 1 or 2 (IDH)-wild-type and IDH-mutant subtypes, with median patient survival of 1.2 and 3.6 years, respectively. Although maximal resection of contrast-enhanced (CE) tumor is associated with longer survival, the prognostic importance of maximal resection within molecular subgroups and the potential importance of resection of non-contrast-enhanced (NCE) disease is poorly understood.

Objective

To assess the association of resection of CE and NCE tumors in conjunction with molecular and clinical information to develop a new road map for cytoreductive surgery.

Design, Setting, and Participants

This retrospective, multicenter cohort study included a development cohort from the University of California, San Francisco (761 patients diagnosed from January 1, 1997, through December 31, 2017, with 9.6 years of follow-up) and validation cohorts from the Mayo Clinic (107 patients diagnosed from January 1, 2004, through December 31, 2014, with 5.7 years of follow-up) and the Ohio Brain Tumor Study (99 patients with data collected from January 1, 2008, through December 31, 2011, with a median follow-up of 10.9 months). Image accessors were blinded to patient groupings. Eligible patients underwent surgical resection for newly diagnosed glioblastoma and had available survival, molecular, and clinical data and preoperative and postoperative magnetic resonance images. Data were analyzed from November 15, 2018, to March 15, 2019.

Main Outcomes and Measures

Overall survival.

Results

Among the 761 patients included in the development cohort (468 [61.5%] men; median age, 60 [interquartile range, 51.6-67.7] years), younger patients with IDH-wild-type tumors and aggressive resection of CE and NCE tumors had survival similar to that of patients with IDH-mutant tumors (median overall survival [OS], 37.3 [95% CI, 31.6-70.7] months). Younger patients with IDH-wild-type tumors and reduction of CE tumor but residual NCE tumors fared worse (median OS, 16.5 [95% CI, 14.7-18.3] months). Older patients with IDH-wild-type tumors benefited from reduction of CE tumor (median OS, 12.4 [95% CI, 11.4-14.0] months). The results were validated in the 2 external cohorts. The association between aggressive CE and NCE in patients with IDH-wild-type tumors was not attenuated by the methylation status of the promoter region of the DNA repair enzyme O6-methylguanine-DNA methyltransferase.

Conclusions and Relevance

This study confirms an association between maximal resection of CE tumor and OS in patients with glioblastoma across all subgroups. In addition, maximal resection of NCE tumor was associated with longer OS in younger patients, regardless of IDH status, and among patients with IDH-wild-type glioblastoma regardless of the methylation status of the promoter region of the DNA repair enzyme O6-methylguanine-DNA methyltransferase. These conclusions may help reassess surgical strategies for individual patients with newly diagnosed glioblastoma.

Diffusion-weighted MR imaging histogram analysis in HIV positive and negative patients with primary central nervous system lymphoma as a predictor of outcome and tumor proliferation

INTRODUCTION

Ki-67 expression, a marker of tumor proliferation, is considered a prognostic factor in primary CNS lymphoma (PCNSL). Apparent diffusion coefficient (ADC) parameters have also been proposed as imaging biomarkers for tumor progression and proliferative activity in various malignancies. The aim of this study is to investigate the correlation between ADC parameters, Ki-67 expression, overall survival (OS) and progression free survival (PFS) in PCNSL.

MATERIALS AND METHODS

Patients diagnosed with PCNSL at MD Anderson Cancer Center between Mar 2000 and Jul 2016 and at Ben Taub Hospital between Jan 2012 and Dec 2016 were retrospectively studied. Co-registered ADC maps and post-contrast images underwent whole tumor segmentation. Normalized ADC parameters (nADC) were calculated as the ratio to normal white matter. Percentiles of nADC were calculated and were correlated with Ki-67 using Pearson's correlation coefficient and clinical outcomes (OS and PFS) using Cox proportional hazards models.

RESULTS

Selection criteria yielded 90 patients, 23 patients living with HIV (PLWH) and 67 immunocompetent patients. Above median values for nADC_mean, nADC₁₅, nADC₇₅ and nADC₉₅ were associated with improved OS in all patients (p < 0.05). Above median values for nADC_min, nADC_mean, nADC₁, nADC₅ and kurtosis were associated with improved PFS in all patients (p < 0.05). In patients with available Ki-67 expression data (n = 22), nADC_mean, nADC₁₅ and nADC₇₅ inversely correlated with Ki-67 expression (p < 0.05). For PLWH, there was no correlation between ADC parameters and Ki-67 expression or clinical outcomes.

CONCLUSIONS

ADC histogram analysis can predict tumor proliferation and survival in immunocompetent patients with PCNSL, but with limited utility in PLWH.

EPCO-13. GENOME-WIDE ASSOCIATION STUDY IN INDIVIDUALS OF ASHKENAZI JEWISH ANCESTRY IDENTIFIES NOVEL RISK LOCI FOR GLIOMA

Population stratification, or systematic differences in allele frequencies between subpopulations, can distort the results from genome-wide association studies (GWAS). While GWAS are usually conducted within continental (e.g. European) ancestry groups, sub-groups may have specific population histories that result in enrichment for risk or protective alleles for complex disease. In this analysis, we examined genetic risk for glioma in a US population with predominantly Ashkenazi Jewish (AJ) ancestry. Genotyping data were obtained from three prior glioma case-control studies. Best-guess assignment to one of seven subcontinental European ancestry groups was performed using AIPS (https://github.com/biomedicaldatascience/AIPS). Out of a total of 6,416 cases and 7,441 controls across all three studies, 202 cases (3% of all cases, 63% GBM) and 403 controls (5% of all controls) were assigned to the AJ ancestry group. Unconditional logistic regression was performed for by study (adjusted for age and first two principal components) and then studies were combined using fixed effects meta-analysis. No associations reached genome-wide significance (p&lt; 5x10-8), including those detected in prior pan-European GWAS. A nominally significant association was detected on chromosome 17 in ASPA (rs9904040, MAF=20%, p=2.61x10-6, Odds ratio=2.22 [95% confidence interval=1.59–3.09]) which is in linkage equilibrium (r2=0.0013) with the previously detected glioma risk SNP in TP53 (MAF=0.3% in this analysis, p=0.8801) in the European population. In our prior pan-European meta-analysis (Melin et al., 2017, this SNP was non-significant (p=0.0620). This study failed to replicate many previously identified glioma risk alleles, likely due to diminished power due to small sample size. We did identify a novel risk allele on chromosome 17 in ASPA, which encodes for aspartoacylase (which catalyzes deacylation of N-acetyl_L-aspartic acid). Larger sample sizes identified via targeted recruitment are necessary in order to fully characterize genetic risk for glioma in this population, including assessment of rare (MAF&lt; 5%) risk allele associations.

EPID-19. RACIAL/ETHNIC DISPARITIES IN TREATMENT PATTERN AND TIME TO TREATMENT FOR ADULTS WITH GLIOBLASTOMA IN THE US

BACKGROUND

Race/ethnicity have been previously shown to significantly affect survival after diagnosis with glioblastoma, but the cause of this survival difference is not known. The aim of this study was to examine variation in treatment pattern and time to treatment by race/ethnicity, and the extent to which this affects survival.

METHODS

Data were obtained from the National Cancer Database (NCDB) for adults &gt;= 40 with glioblastoma (histologic codes 9440–9442 and topographical codes C71.0–C71.9) from 2004–2016 (N=117,710). Treatment patterns and time to treatment by race/ethnicity were compared using univariable and multivariable logistic and linear regression models, respectively. Models were adjusted for age, sex, insurance status, pre-existing comorbidities, type of treating institution, and distance to institution.

RESULTS

Black non-Hispanics (BNH) were 17% less likely to receive radiation (p=1.47x10-8) and 32% less likely to receive chemotherapy (p=1.10x10-31) than White non-Hispanics (WNH). Among those that did receive treatment, it took 3.3 additional days on average for BNH to receive radiation (p=2.12x10-11) and 4.6 additional days to receive chemotherapy in comparison to WNH (p=4.14x10-10). Hispanics were 21% less likely to receive radiation (p=4.79x10-12), and 23% less likely to receive chemotherapy (p=7.51x10-14) than WNH. Among those that did receive treatment, it took 3.3 additional days on average for Hispanics to receive radiation (p=4.07x10-9) and 4 additional days to receive chemotherapy in comparison to WNH (p=1.51x10-6). There were no significant differences in time to surgery, or in to treatment for Asian Pacific Islanders or American Indian/Alaska Natives.

CONCLUSIONS

Both likelihood of receiving treatment and time to radiation and chemotherapy vary significant between BNH and Hispanics as compared to WNH, and this difference is not fully explained by comorbidities or access to health care.

BIOM-50. GENETIC PREDISPOSITION TO LONGER TELOMERE LENGTH AND RISK OF CHILDHOOD, ADOLESCENT AND ADULT-ONSET EPENDYMOMA

INTRODUCTION

Ependymoma is the third most common brain tumor in children, with well-described molecular characterization but poorly understood underlying germline risk factors. Telomerase reactivation in somatic cells has been linked to ependymoma progression, recurrence, and survival, and has been implicated as an important prognostic marker and potential therapeutic target.

METHODS

To investigate whether inherited predisposition to longer telomere length influences ependymoma risk, we utilized case-control data from three studies: 1) a population-based pediatric and adolescent ependymoma case-control sample from California (153 cases, 696 controls), 2) a hospital-based pediatric posterior fossa type A ependymoma (EPN-PF-A) case-control study from Toronto’s Hospital for Sick Children and the Children’s Hospital of Philadelphia (83 cases, 332 controls), and 3) a multicenter adult-onset ependymoma case-control dataset nested within the Glioma International Case-Control Consortium (GICC) (103 cases, 3287 controls). We investigated the individual effect of telomere-length associated SNPs on ependymoma risk, as well as the combined effect of these SNPs through polygenic score and Mendelian randomization analyses.

RESULTS

We observed an association between genetic predisposition to longer LTL and increased risk of adolescent-onset (P= 3.97x10-3) and adult-onset (P =0.042) ependymoma, but not ependymoma diagnosed in children &lt; 12 years old (P=0.21), or among the pediatric EPN-PF-A sample (P=0.59). Comparing ependymoma patients ages 12–19 to those under 12 years of age demonstrated that age significantly modified the association between longer telomere length and ependymoma risk (P=0.021).

CONCLUSIONS

These findings complement emerging literature suggesting that dysregulated telomere maintenance is important for ependymoma pathogenesis and that longer telomere length is a risk factor for various neoplasms of the peripheral and central nervous system.

COVD-31. THE STATE OF NEURO-ONCOLOGY DURING THE COVID-19 PANDEMIC: A WORLDWIDE ASSESSMENT

To assess the impact of the pandemic on the field, we performed an international web-based survey of practitioners, scientists, and trainees from 21 neuro-oncology organizations across 6 continents from April 24 through May 17. Of 582 respondents, 258 (45%) were in the US, and 314 (55%) were international. 80.4% were affiliated with academic institutions. 94% respondents reported changes in clinical practice; 95% reported conversion to telemedicine for at least some appointments. However, almost 10% practitioners felt the need to see patients in person specifically because of billing concerns and perceived institutional pressure. Over 50% believed neuro-oncology patients were at increased risk of contracting COVID-19. 67% practitioners suspended enrollment for at least one clinical trial: 53% suspended phase II and 62% suspended phase III trial enrollment. 71% clinicians feared for their or their families’ safety, specifically because of their clinical duties. 20% percent said they did not have enough PPE to work safely; about the same percentage were unhappy with their institutions’ response to the pandemic. 43% believed the pandemic would negatively affect their academic career, and 52% fellowship program directors were worried about losing funding for their training programs. While 69% respondents reported increased stress, 44% were offered no psychosocial support. 37% had their salary reduced. 36% researchers had to temporarily close their laboratories. In contrast, the pandemic created positive changes in perceived patient and family satisfaction, quality of communication, and use of technology to deliver care and interactions with other practitioners. CONCLUSIONS: The pandemic has altered standard treatment schedules and limited investigational treatment options for patients. In some cases, clinicians felt institutional pressure to continue conducting billable in-person visits when telemedicine visits would have sufficed. A lack of institutional support created anxiety among clinicians and researchers. We make specific recommendations to guide clinical and scientific infrastructure moving forward.

Abstract 2121: Genetic correlation between lung cancer and environmental exposures

Introduction: Lung cancer is the leading cause of cancer-related deaths. 10% of never-smokers develop lung cancer. Currently, no genetic-based lung cancer screening tool exists. As a substitute, phenotypic traits can serve as surrogate markers for lung cancer risk. Our study focuses on identifying novel phenotypes associated with lung cancer. Genome-wide association studies (GWAS) are useful in elucidating complex inheritance patterns and genetic architecture. Cross-trait linkage disequilibrium score regression (LDSC) specifically allows for use of GWAS summary statistics to identify genetic correlations between phenotypes of interest. This method allows for accurate calculations of genetic correlation, as it neutralizes effects from population stratification or cryptic relatedness.

Methods: We used LDSC to (1) confirm prior phenotypic trait associations with lung cancer and to (2) identify novel associations. We measured pairwise genetic correlation (rg) and SNP heritability (h2) (the proportion of phenotypic variance observed in a population that can be explained genetically) between multiple phenotypes and lung cancer using summary statistics from the UK Biobank and OncoArray lung consortium. In addition, we conducted analysis after removal of genome regions related to smoking effects that enables us to correct the potential confounding effect in lung cancer.

Results: Significant negative genetic correlations were found to exist between lung cancer and environmental factors. Overall alcohol use was significantly correlated with lung cancers. The effect observed was split, with a positive correlation for beer and cider intake (rg = 0.2957, p = 3.936 × 10-8) and a negative correlation with wine intake (rg = -0.3281, p = 2.251 × 10-14) for overall lung. Significant correlations existed between lung cancer and health metrics. A positive correlation was found between lung cancer and increased BMI (rg = 0.1986, p = 3.57 × 10-9). This finding was consistent across other BMI related metrics and within histological subtypes of lung cancer, including for lung adenocarcinoma (rg = 0.1059, p = 3.688 × 10-3) and lung small cell carcinoma (rg = 0.2393, p = 6.463 × 10-7). In comparison, physical conditioning metrics such as cycling to work had a negative correlation with lung cancer (rg = -0.2714, p = 5.690 × 10-5). Further, negative correlations were observed between being breastfed as a baby and lung cancer (rg = -0.320, p = 1.554 × 10-6). Each of these associations maintained its significance even after the removal of smoking-related SNPs.

Conclusions: This analysis demonstrates a genetic basis for the shared genetic architecture between environmental factors and lung oncogenesis. We identify several novel associations, including a correlation between breastfeeding and lung cancer. Further studies are necessary in order to confirm these associations and investigate driving genetic mechanisms.

Citation Format: Rowland West Pettit, Jinyoung Byun, Younghun Han, Jacob Edelson, Quinn Ostrom, Kyle Walsh, Melissa Bondy, James McKay, Christopher Amos, INTEGRAL Consortium. Genetic correlation between lung cancer and environmental exposures [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2121.

Multiscale, multimodal analysis of tumor heterogeneity in IDH1 mutant vs wild-type diffuse gliomas

Glioma is recognized to be a highly heterogeneous CNS malignancy, whose diverse cellular composition and cellular interactions have not been well characterized. To gain new clinical- and biological-insights into the genetically-bifurcated IDH1 mutant (mt) vs wildtype (wt) forms of glioma, we integrated data from protein, genomic and MR imaging from 20 treatment-naïve glioma cases and 16 recurrent GBM cases. Multiplexed immunofluorescence (MxIF) was used to generate single cell data for 43 protein markers representing all cancer hallmarks, Genomic sequencing (exome and RNA (normal and tumor) and magnetic resonance imaging (MRI) quantitative features (protocols were T1-post, FLAIR and ADC) from whole tumor, peritumoral edema and enhancing core vs equivalent normal region were also collected from patients. Based on MxIF analysis, 85,767 cells (glioma cases) and 56,304 cells (GBM cases) were used to generate cell-level data for 24 biomarkers. K-means clustering was used to generate 7 distinct groups of cells with divergent biomarker profiles and deconvolution was used to assign RNA data into three classes. Spatial and molecular heterogeneity metrics were generated for the cell data. All features were compared between IDH mt and IDHwt patients and were finally combined to provide a holistic/integrated comparison. Protein expression by hallmark was generally lower in the IDHmt vs wt patients. Molecular and spatial heterogeneity scores for angiogenesis and cell invasion also differed between IDHmt and wt gliomas irrespective of prior treatment and tumor grade; these differences also persisted in the MR imaging features of peritumoral edema and contrast enhancement volumes. A coherent picture of enhanced angiogenesis in IDHwt tumors was derived from multiple platforms (genomic, proteomic and imaging) and scales from individual proteins to cell clusters and heterogeneity, as well as bulk tumor RNA and imaging features. Longer overall survival for IDH1mt glioma patients may reflect mutation-driven alterations in cellular, molecular, and spatial heterogeneity which manifest in discernable radiological manifestations.

EPID-03. HISTOLOGY-SPECIFIC BRAIN TUMOR INCIDENCE AND SURVIVAL VARIES BY SEX

BACKGROUND

Significant sex differences exist in cancer, and males have higher incidence and lower survival compared to females for most cancers. No large-scale studies have systematically examined sex differences in incidence and survival across all primary brain histologies. We performed a comprehensive investigation of the differences in incidence and survival in patients diagnosed with primary malignant brain and other CNS tumors by specific histologies.

METHODS

Age-adjusted incidence rate ratios (IRR) and 95% confidence intervals (945% CI) were generated from the United States Cancer Statistics (USCS) Public Use Database. Data from the Surveillance, Epidemiology, and End-Results (SEER) program were used to calculate overall survival. Data was restricted to patients with histologically or radiologically confirmed, primary malignant tumors diagnosed between 2001 and 2015. Histological groupings were categorized based on the Central Brain Tumor Registry of the United States (CBTRUS). Cox proportional hazards models were used to calculate hazard ratios (HR) adjusted for age for males as compared to females.

RESULTS

Males exhibited higher incidence than females in all brain histologies except meningioma (IRR=0.83; 95% CI 0.73–0.93) and other neuroepithelial tumors (i.e. polar spongioblastomas and astroblastomas) (IRR=0.48; 95% CI 0.26–0.88). Males experienced better overall survival in germ cell tumors, cysts and heterotopias (HR=0.68; 95% CI 0.49–0.94) compared to females, but were observed to have lower survival in all other histologies. Survival was lowest for males among patients with nerve sheath tumors (HR=2.32; 95% CI 1.31–4.12) and other neoplasms related to the meninges (e.g. chondrosarcomas and chordomas) (HR=2.23; 95% CI 1.24–3.99). Survival in meningioma patients was significantly higher in females (HR=1.49; 95% CI 1.25–1.77). Patients with glioblastomas, had a slightly worse survival outcome in males (HR=1.02, 95% CI 1.00–1.05).

CONCLUSION

Understanding the role of sex differences is critical for addressing sex based inequalities and needs to be taken into account in clinical paradigms.

PDTM-33. EUROPEAN GENETIC ANCESTRY ASSOCIATED WITH RISK OF CHILDHOOD EPENDYMOMA

BACKGROUND

Ependymoma is a histologically-defined central nervous system tumor most commonly occurring in children. Incidence differs by race/ethnicity, with individuals of European ancestry at highest risk. No large-scale genomic analyses of ependymoma predisposition have been conducted to date. We aimed to determine whether extent of European genetic ancestry is associated with ependymoma risk.

METHODS

In a multi-ethnic study of Californian children (327 cases, 1970 controls), we estimated the proportions of European, African, and Native American ancestry among admixed Hispanic and African-American subjects and estimated European substructure among non-Hispanic white subjects using genome-wide data. We tested whether genome-wide ancestry differences were associated with ependymoma risk and performed admixture mapping to identify associations with local European ancestry. We also re-analyzed CBTRUS data to examine subtype-specific differences in ependymoma incidence across racial/ethnic groups.

RESULTS

Each 20% increase in European ancestry was associated with 1.31-fold greater odds of ependymoma among Hispanic and African-American subjects (95% CI: 1.08–1.59, Pmeta=6.7×10–3). Among non-Hispanic whites, European ancestral substructure was also significantly associated with ependymoma risk. Local admixture mapping revealed a peak at 20p13 associated with increased local European ancestry, and genotype association analysis in the region identified an association upstream of R-spondin 4 that survived Bonferroni correction (P=2.2x10-5) but was not validated in an independent set of posterior fossa type A (PF-EPN-A) patients. In complementary CBTRUS analyses, American Indian/Alaskan Natives were at reduced risk relative to non-Hispanic whites (RR=0.64, 95% CI:0.46–0.87), as were African-Americans (RR=0.67, 95% CI:0.60–0.74) and Asian/Pacific Islanders (RR=0.86, 95% CI:0.73–1.00). Although overall ependymoma rates were similar in U.S. Hispanics (RR=0.96, 95% CI:0.88–1.05), lower rates were observed for myxopapillary ependymoma and other spinal ependymoma.

CONCLUSION

Inter-ethnic differences in ependymoma risk vary by histopathologic and potentially molecular subgroup, and are recapitulated in the genomic ancestry of ependymoma patients.

GENE-11. LDSCORE REGRESSION IDENTIFIES NOVEL ASSOCIATIONS BETWEEN GLIOMA AND AUTO-IMMUNE CONDITIONS

BACKGROUND

Prior epidemiological studies in glioma have identified 25 germline risk variants, as well as risk associations with exposure to ionizing radiation (which increases risk) and history of allergies and aspirin use (which decrease risk). In this analysis we LDscore regression, which leverages single SNP associations and known patterns of linkage disequilibrium (LD) to estimate the genetic correlation between phenotypes, to confirm prior associations as well as attempt to identify novel phenotype associations for traits not previously assessed that may improve genetic prediction for glioma.

METHODS

Summary statistics for all glioma, GBM, and non-GBM were obtained from a prior meta-analysis conducted by Melin, et al. Summary statistics for 13 immune- and atopy-related traits were obtained from the prior case-control studies and the UK biobank. Data were filtered to include only SNPs with imputation INFO value >0.7, and minor allele frequency >0.01, excluding SNPs within the HLA region. Pairwise genetic correlation between these traits was generated using LDSC. Associations were considered significant at p< 0.05

RESULTS

Significant negative correlations were identified between glioma and ulcerative colitis (rg= -0.4039, p=4.91x10-10), celiac disease (rg= -0.2028, p=1.18x10-4), lupus (rg= -0.0956, p=0.0083), and multiple sclerosis (rg= -0.5755, p=4.46x10-9). These associations were generally consistent in both GBM and non-GBM. There was a significant correlation between both self-reported (rg= -0.102, p=0.0233) and doctor diagnosed (rg= -0.116, p=0.0305) hayfever/allergic rhinitis and GBM only.

CONCLUSIONS

This analysis demonstrates a genetic basis for previously identified protective effect of allergic rhinitis on GBM, and identifies novel associations between multiple auto-immune traits and glioma. Further studies are necessary in order to confirm these associations and identify the mechanism through which increased immune activity may lower risk of glioma.

EPID-04. ASSOCIATION BETWEEN URBANICITY AND SURGICAL TREATMENT AMONG PATIENTS WITH PRIMARY GLIOBLASTOMA IN THE UNITED STATES

BACKGROUND

Glioblastoma (GBM) is the most common malignant brain and other central nervous system (CNS) tumor and also the most fatal. Extent of surgical resection is one of the most significant factors associated with improved survival. Historically, patients living in non-metropolitan counties have limited access to optimal treatment and healthcare services. The aim of this study is to determine if there is an association between urbanicity and surgical treatment patterns among patients with primary GBM.

METHODS

Cases with histologically-confirmed, primary GBM diagnosed between 2005 and 2015 were obtained from the Central Brain Tumor Registry of the United States (CBTRUS). Site specific surgery codes for brain and CNS defined surgery were grouped as follows: gross total resection (GTR; 30,55), subtotal resection (STR; 21, 40), biopsy only (20) and none (00). Urbanicity was defined using the 2013 USDA Rural Urban Continuum (RUC) Code Definitions (metropolitan: RUC 1–3, non-metropolitan: RUC 4–9). Multivariable logistic regression models were constructed to assess the association between urbanicity and receipt of surgical treatment (GTR/STR vs. biopsy only/none) and extent of resection (GTR vs. STR), adjusted for age at diagnosis, sex, race, U.S. regional division, and primary site of tumor.

RESULTS

Residence in a metropolitan county was significantly associated with receiving surgical treatment among patients with GBM, with patients residing in non-metropolitan counties 7% less likely to receive surgical treatment (adjusted OR=0.93, 95% CI: 0.89–0.96, P value: < .0001). Among those who received surgical treatment, metropolitan status was not significantly associated with receiving GTR vs. STR (adjusted OR=0.99, 95% CI: 0.94–1.04, P value: 0.620).

CONCLUSIONS

Among U.S. patients with GBM, urbanicity is associated with receipt of surgical treatment, but among patients who receive surgery, was not associated with extent of resection. These results point to potential differences in access to healthcare for those in non-metropolitan areas that warrant further exploration.

EPID-19. SHARED GENOMIC ARCHITECTURE OF GLIOMA AND NEURO-COGNITIVE AND NEURO-PSYCHIATRIC TRAITS REVEALED BY LD-SCORE REGRESSION

BACKGROUND

Genome-wide analyses estimate glioma heritability at 25%, yet known risk loci account for just one-third of this risk and suggest that sporadic glioma is a highly polygenic disease with hitherto unaccounted for genomic architecture. LD-score regression leverages results from genome-wide association studies (GWAS) and known patterns of linkage disequilibrium (LD) to estimate correlation between the genetic architecture of multiple phenotypes. We applied LD-score regression to identify associations with neuro-cognitive and neuro-psychiatric traits not amenable to study in prior glioma case-control analyses.

METHODS

GWAS summary statistics were obtained from the Glioma International Case-Control Consortium (GICC) meta-analysis (Melin, et al. 2017) and for 64 neuro-cognitive and neuro-psychiatric traits primarily from the UK Biobank. Included SNPs had quality scores ≥0.70 and minor allele frequency ≥0.01. Pairwise genetic correlations between traits were estimated using the LDSC package. P-values < 7.8x10-4 (i.e. 0.05/64) were considered significant.

RESULTS

Significant negative correlations were identified between the genetic architectures of glioma and bipolar disorder (Rg=-0.41, P=1.4x10-9) and schizophrenia (Rg=-0.29, P=7.1x10-9), consistent in both GBM and LGG. Significant positive correlations were identified with measures of educational attainment, including age at educational completion (Rg=0.11, P=2.0x10-4), obtaining a college degree (Rg=0.086, P=4.9x10-4), college attendance (Rg=0.086, P=5.9x10-4), and years of education (Rg=0.081, P=7.7x10-4). These associations were notably stronger with LGG. A number of additional nominal associations were observed, including with anorexia (anti-correlated) and performance on a pair-matching cognitive test (positively correlated). Importantly, LD-score regression did not identify an association between glioma risk in GICC data and Townsend deprivation index in UK Biobank data.

CONCLUSIONS

These results implicate a shared genetic basis for glioma and several psychiatric and cognitive traits. Further research is needed to understand these associations and to explore underlying mechanisms, including the mediating effects of neuro-inflammation, developmental differences in neural‒glial cell circuitry, and inter-individual variation in myelination.

BSCI-06. FREQUENCY OF BRAIN METASTASIS FROM BREAST AND LUNG CANCER IN THE UNITED STATES -- A POPULATION-BASED ASSESSMENT

BACKGROUND: Brain metastases (BM) are the most common central nervous system tumor in the United States and occur with increasingly frequency due to improved screening and therapeutics leading to improved survival. Current estimates of frequency of BM vary significantly by cancer site and are typically not population-based. Population-based estimates of incidence have recently become possible due to collection of data on BM identified at diagnosis (“synchronous” BM, SBM). BM may occur at any point after cancer diagnosis. We report our recent population-based estimates of SBM and period incidence of BM (PBM) from breast (BC) and lung cancer (LC). METHODS: Data from Surveillance, Epidemiology, and End Results (SEER, 2010–2016 diagnoses) were used to estimate SBM and linked data from SEER-Medicare (2008–2012 diagnoses for individuals 65+, with 2007–2014 claims) were used to estimate PBM, for BC and LC overall and by BC and LC subtypes. RESULTS: Within the SEER data, 10.9% of LC cases presented with SBM (15.5% in small cell LC [SCLC], and 10.8% in non-small cell LC [NSCLC]); 0.4% of BC cases presented with SBM, 0.7% in triple negative (TNBC), 0.8% for HER2+, and 0.2% for ER+\PR+\HER2-. Within the SEER-Medicare data, 13.5% of LC overall had LBM with 23.1% for SCLC and 15.3% for NSCLC; 1.8% of BC overall had LBM with 4.2% in triple negative (TNBC), 3.1% for HER2+, and 1.1% for ER+\PR+\HER2. CONCLUSION: Frequency of synchronous and period BM varies by originating site as well as subtype. The new SBM variable in SEER allows for estimation of this important statistic, while the SEER-Medicare linked data allows for estimation of PBM, both on a population-level for the US population. These estimates are useful to clinical practice and critical for estimating morbidity and mortality due to BM.

Abstract 2745: Tumor microenvironment and host genetics impact glioma progression in a Collaborative Cross-based orthotopic allograft model

Gliomas are diffusely invasive brain tumors with fatal outcomes and few effective treatments. Precision medicine focuses on targeting the genetics of individual tumors, but not host genetics, despite studies that have linked germline polymorphisms with glioma risk. Accordingly, glioma survival studies in mice utilize genetically variable tumors on identical host genetic backgrounds, which fails to differentiate between cancer cell-autonomous (CCA) and tumor microenvironment (TME) effects on glioma progression and host survival. The Collaborative Cross (CC) is a panel of genetically diverse mouse strains derived from both wild- and traditional inbred laboratory strains that facilitates high-resolution genetic mapping in models of complex disease. Here, we implement a novel platform to discover genetic modifiers of both CCA and TME phenotypes using genetically defined orthotopic murine allograft gliomas and CC hosts. We stereotactically injected Nf1;Trp53-/-oligodendrocyte progenitor-derived mouse tumor cells into syngeneic C57BL/6 control mice and 14 different CC strains. Seven strains survived significantly longer than controls (P&lt;0.05), suggesting slower tumor growth (Gs, growth slow). The remaining 7 strains survived similarly to controls, suggesting fast growth (Gf, growth fast). Variable tumor growth in CC mice suggests that genetic background influences molecular processes in the TME that inhibit or potentiate tumor growth, respectively. To identify candidate genes, we performed RNA sequencing on 36 tumors from 3 Gf strains, 4 Gs strains, and controls. 134 genes were differentially expressed among Gf, Gs, and control tumors (P&lt;0.05). Hierarchical clustering on these genes revealed that Gs strains clustered separately from Gf and controls. Gene ontology analysis using GOrilla showed 30 enriched processes, (FDR q&lt;0.001), all of which were involved in immune responses or extracellular matrix biology. These results suggest that Gs strains activate immune and TME processes that slow tumor growth. Quantitative trait locus (QTL) analyses of host genetics and tumor data are pending and will facilitate identification of genetic variants that influence TME effects on tumor progression.

Citation Format: Kasey Skinner, Martin Ferris, Ryan Bash, Abigail Shelton, Erin Smithberger, Steve Angus, Brian Golitz, Noah Sciaky, Jeremy Simon, Jason Stein, Glenn Matsushima, Quinn Ostrom, Lindsay Stetson, Jill Barnholtz-Sloan, Harshil Dhruv, Michael Berens, Fernando Pardo Manuel de Villena, C. Ryan Miller. Tumor microenvironment and host genetics impact glioma progression in a Collaborative Cross-based orthotopic allograft model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2745.

2245. Primary Central Nervous System Lymphoma in Patients with HIV and Non-HIV: Should We Treat Them Differently?

Background

Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin lymphoma, mostly diffuse large B-cell type. In patients living with HIV (PLWH), PCNSL is associated with Epstein-Barr virus. The optimal diagnostic and prognostic tools, and treatment are yet to be defined. PLWH are typically excluded from prospective studies. The management of PCNSL is adopted from immunocompetent patients.

Methods

We retrospectively reviewed 122 PCNSL cases presenting to MD Anderson Cancer Center from 2000 to 2016 (n = 84) and Ben-Taub Hospital from 2012 to 2016 (n = 38) to evaluate and compare the clinical characteristics, management, and clinical outcomes in patients with or without HIV infection.

Results

Among 122 PCNSL cases, 21% had positive HIV test, of those, 89% had CD4 < 200 and 77% were not on antiretrovirals and not virally suppressed. PLWH were significantly younger (37 vs. 62 years. P < 0.01), and more likely to be African-Americans (61% vs. 7%; P < 0.01) and males (73% vs. 50%; P = 0.04) than non-HIV patients. There were no differences in presenting symptoms, ocular involvement, B-symptoms, and deep brain involvement. PLWH were more likely to have multiple brain lesions (69% vs. 44%, P = 0.02). Immunohistochemistry prognostic markers and the International Extranodal Lymphoma Study Group (IELSG) prognostic score were not different between HIV and non-HIV patients. Nevertheless, treatment strategies varied significantly. PLWH were more likely to receive whole brain radiation therapy as sole treatment (65% vs. 4%) and palliative care (12% vs. 2%), and less likely to receive chemotherapy (23% vs. 94%) (P < 0.01). Also, 13% of the patients (all non-HIV) underwent autologous stem cell transplant. Most PLWH (88%) started antiretroviral therapy after diagnosis. Higher IELSG score was an independent predictor of mortality in multivariate regression analysis. The 2-year survival did not differ between PLWH and non-HIV patients [46% (30–72%) vs. 61% (52–72%) (P = 0.12)].

Conclusion

Variation in the treatment of PCNSL between HIV and non-HIV patients is not fully explained by baseline characteristics and prognostic factors. More efforts are needed to identify causes underlying these disparities and ways to alleviate them.

Disclosures

All authors: No reported disclosures.

Abstract 1302: Genome-wide association study of glioma reveals specific differences in genetic susceptibility to glioblastoma and non-glioblastoma

BACKGROUND: Glioma accounts for ~27% of all primary brain tumors and is responsible for ~13,000 cancer-related deaths in the US each year. Glioma tumors can be broadly classified into glioblastoma (GBM) and lower-grade non-GBM. Typically gliomas have a poor prognosis irrespective of medical care, with the most common form, GBM, having a five-year survival rate of only 5%. While genome-wide association studies (GWAS) have transformed our understanding of glioma susceptibility, individual studies have had limited power to identify risk loci.

METHODS: We performed the largest glioma GWAS to date, comprising a meta-analysis of six existing GWAS (6,405 cases, 14,100 controls) as well as new GWAS from the Glioma International Case Control Consortium (GICC; 4,572 cases and 3,286 controls) and University of California, San Francisco (UCSF)-Mayo (1,519 cases, 804 controls), totaling 12,496 cases (6,191 classified as GBM, 5,819 as non-GBM) and 18,190 controls.

RESULTS: We identified five new risk loci for GBM at 1p31.3 (rs12752552; near JAK1, P=2.04×10-9, odds ratio (OR)=1.22), 11q14.1 (rs11233250; P=9.95×10-10, OR=1.24), 16p13.3 (rs2562152; near MPG, P=1.93x10-8, OR=1.21), 16q12.1 (rs10852606; HEATR3, P=1.29×10-11, OR=1.18), 22q13.1 (rs2235573; P=1.76×10-10, OR=1.15) and eight for non-GBM at 1q32.1 (rs4252707; MDM4, P=3.34×10-9, OR=1.19), 1q44 (rs12076373; AKT3, P=2.63×10-10, OR=1.23), 2q33.3 (rs7572263; near IDH1, P=2.18×10-10, OR=1.20), 3p14.1 (rs11706832; LRIG1, P=7.66×10-9, OR=1.15), 10q24.33 (rs11598018; OBFC1, P=3.39×10-8, OR=1.14), 11q21 (rs7107785; P=3.87×10-10, OR=1.16), 14q12 (rs10131032; P=5.07x10-11, OR=1.33) and 16p13.3 (rs3751667; P=2.61×10-9, OR=1.18). Case-only analyses confirmed the specificity of 11q14.1, 16p13.3 and 22q13.1 associations for GBM and 1q44, 2q33.3, 3p14.1, 11q21 and 14q12 for non-GBM tumors. In the combined meta-analysis, among previously published glioma risk SNPs, those for all glioma at 17p13.1 (TP53), GBM at 5p15.33 (TERT), 7p11.2 (EGFR), 9p21.3 (CDKN2B-AS1) and 20q13.33 (RTEL1) and for non-GBM at 8q24.21 (CCDC26), 11q23.2, 11q23.3 (PHLDB1) and 15q24.2 (ETFA) showed even greater evidence for association. SNPs at 10q25.2 and 12q12.1 for non-GBM tumors retained genome-wide significance (i.e. P&lt;5.0x10-8). Associations at the previously reported loci for GBM at 3q26.2 (near TERC) and 12q23.33 (POLR3B) did not retain statistical significance.

CONCLUSIONS: Our findings substantiate genetic susceptibility to GBM and non-GBM glioma being highly distinct, consistent with their distinctive molecular profiles presumably resulting from different etiological pathways. Functional analyses should lead to further insights into the biological basis of the different glioma histologies. Such information can inform gene discovery initiatives and therefore have a measurable impact on the successful development of new therapeutic agents.

Citation Format: Ben Kinnersley, Beatrice S. Melin, Jill S. Barnholtz-Sloan, Margaret R. Wrensch, Christoffer Johansen, Dora Il’yasova, Quinn Ostrom, and members of GICC, Karim Labreche, Jeanette E. Eckel-Passow, Paul A. Decker, Marianne Labussière, Ahmed Idbaih, Khe Hoang-Xuan, Anna-Luisa Di Stefano, Karima Mokhtari, Jean-Yves Delattre, Pilar Galan, Konstantinos Gousias, Johannes Schramm, Minouk J. Schoemaker, Sarah J. Fleming, Stefan Herms, Stefanie Heilmann, Marcus M. Nöthen, Heinz-Erich Wichmann, Stefan Schreiber, Anthony Swerdlow, Mark Lathrop, Matthias Simon, Marc Sanson, Preetha Rajaraman, Stephen Chanock, Martha Linet, Zhaoming Wang, Meredith Yeager, Rose K. Lai, Elizabeth B. Claus, Sara H. Olson, Robert B. Jenkins, Richard S. Houlston, Melissa L. Bondy. Genome-wide association study of glioma reveals specific differences in genetic susceptibility to glioblastoma and non-glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1302. doi:10.1158/1538-7445.AM2017-1302