BIOM-23. MOLECULAR PROFILING IDENTIFIES NOVEL BIOMARKERS IN A RURAL COHORT OF PATIENTS WITH GLIOBLASTOMA. (9th November 2020)

• Record Type: Journal Article
• Authors: Bystrom, Rebecca; Craig, Wendy; Rueter, Jens; Lu-Emerson, Christine
• Is Part Of: Neuro-oncology. Volume 22(2020)Supplement 2
• Page Start: ii6
• Page End: ii6
• Publication Date: 2020-11-09
• Subjects: Brain Neoplasms -- Periodicals; Brain -- Tumors -- Periodicals; Brain -- Cancer -- Periodicals; Nervous system -- Cancer -- Periodicals; 616.99481
• DOI: 10.1093/neuonc/noaa215.023
• Languages: English
• ISSNs: 1522-8517

Abstract

Abstract: BACKGROUND: The rural state of Maine has one of the highest incidences of primary malignant brain cancer in the United States. We sought to investigate the genomic landscape of glioblastoma (GBM) in Maine. METHODS: Targeted next generation sequencing of 209 cancer related genes was performed on tumor samples from 60 patients diagnosed with GBM at our institution between 2014 and 2019. We compared mutation frequencies between patients grouped according to the published median overall survival for GBM: < 14 months (n = 14) and ≥ 14 months (n = 43, including 23 patients still alive). We excluded patients who were alive but diagnosed less than 14 months prior to analysis (n = 3). RESULTS: Across all groups frequent molecular markers included EGFR (49%), TP53 (38%), CDKN2A (17.5%), PIK3R1 (15.8%), PDGFRA (12.2%), PIK3CA (10.5%), PTEN (19%), NF1 (10.5%) and IDH1/2 (10%); frequencies did not differ significantly between groups. MGMT methylation was similar between groups (6/14 (42.9%) in shorter survivors and 18/41 (43.9%) in longer survivors). FANC group mutations were more frequent in longer survivors (13/43 [30%] versus 0/14 [0%], p = 0.025). Among shorter survivors CDKN2A deletions were slightly more frequent (5/14 (45%) versus 5/43 (11%), p = 0.099). FES, KIAA1524, FLT (all 5/43, 11.6%) and EPH (6/43, 14.0%) were only observed in longer survivors. These mutations co-occurred with 4/5 CDKN2A deletions in longer survivors. After excluding those 4 cases, CDKN2A deletions were significantly associated with shorter survival (5/14 [35.7%] versus 1/39 [2.6%]), p=0.004. CONCLUSION: FANC group mutations may be a novel prognostic biomarker for longer survival in a rural cohort with GBM. CDKN2A deletions may be associated with shorter survival, but this may be ameliorated by co-occurring FES, KIAA1524, FLT, and EPH mutations.