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

Abstract BACKGROUND A newly developed brain molecular marker (BMM) data item was implemented by U.S. cancer registries for individuals diagnosed with tumors in 2018—including IDH and 1p/19q-codeletion statuses adult-type diffuse gliomas. We thus investigated the testing/reporting completeness of BMM METHODS Cases histopathologically-confirmed glioblastoma, astrocytoma, oligodendroglioma 2018 were identified National Cancer Database. Adjusted odds ratios (ORadj) 95% confidence intervals (95CI) evaluated association selected patient, treatment, facility-level characteristics using multivariable logistic regression. As a secondary analysis, predictors MGMT promoter methylation among IDH-wildtype glioblastoma assessed. RESULTS Among 7,370 histopathologically-diagnosed gliomas nationally, overall 81%. Compared to biopsy-only cases, increased subtotal (ORadj= 1.38 [95CI: 1.19-1.61], p< 0.001) gross total resection (ORadj=1.53 1.33-1.77], 0.001). Furthermore, lowest at community centers (hospitals (65.8%; ORadj=0.33 0.24-0.44], highest academic/NCI-designated comprehensive (85.3%; referent). By geographical location, ranged from high 86.9% New England (referent) low 75.2% West South Central region (ORadj=0.55 0.39-0.76]; Extent resection, facility type, location additionally significant cases. CONCLUSION Initial favorable, although patterns varied hospital attributes extent resection.