| ORIGINAL ARTICLE
|Year : 2019 | Volume
| Issue : 1 | Page : 65-69
Cell-free circulating tumor DNA in patients with high-grade glioma as diagnostic biomarker – A guide to future directive
Khaleel Ibrahim Ahmed, HB Govardhan, Manisha Roy, T Naveen, P Siddanna, P Sridhar, MN Suma, Noopur Nelson
Department of Radiation Oncology, Kidwai Memorial Institute of Oncology, Bangalore, Karnataka, India
BACKGROUND: Owing to the aggressive nature of high-grade gliomas (HGGs), its early diagnosis holds the key to a favorable prognosis. Currently, tissue biopsy is the gold standard to verify HGG's initial diagnosis and can be challenging due to its invasive nature. In this study, our objective was a noninvasive panel for timely detection of HGG and its progression using cell-free circulating tumor DNA (cfTDNA).
MATERIALS AND METHODS: Twenty-seven patients with HGG were tested with a 50-gene tumor panel. cfTDNA isolated from serum was checked for single-nucleotide variations (SNVs) or copy number alterations using targeted next-generation sequencing, with further validation of results by checking respective formalin-fixed paraffin-embedded tumor tissues for the same genetic alterations.
RESULTS: About 88.8% of the patients were detected with HGG-associated cfTDNA. Around 25% patients were detected with one, 25% patients had three, 25% patients had four, and 12.5% patients each had five and six genetic alterations. About 12 of 50 genes were detected in the serum samples. The SNVs detected included TP53 in 87.5% of patients; PIK3CA and EGFR in 50% of patients; PTEN in 37.5%; KIT and VHL in each 25% of patients; and RB1, NF2, MET, ATRX, CDK2A, and CTNNB1 each in 8.3%–16.6%. On combining EGFR, KIT, PTEN, PIK3CA, TP53, and VHL genes (Govardhan Diagnostic Genetic Module for high-grade glioma), at least one of the genetic alterations was found in 100% of patients.
Conclusion: These findings illustrate that cfTDNA is easily demonstrable and can be used as a surrogate to tissue biopsy in brain tumor.
H B Govardhan
Department of Radiation Oncology, Kidwai Memorial Institute of Oncology, Bangalore, Karnataka
Source of Support: None, Conflict of Interest: None
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