Abstract 11
Category: Clinical
At the end of the session, participants will be able to:
- To develop an approach to evaluating diagnostic investigations of diffuse gliomas using a cost-benefit
analysis framework. - To compare FISH and NGS in the context of detecting 1p/19q-codeletion.
COI Disclosure:
None to disclose.
Presenter
My name is Jacob and I am a third-year Neuropathology resident at the Schulich School of Medicine and Dentistry in London, ON, Canada. Prior to this, I attended medical school at the same, where I started to cultivate a still-growing interest and joy in all things neuropathology. My sincere thanks for the opportunity to attend the CANP 2023 Annual
Meeting, and I hope to see you there!
My research endeavors currently include, but are not limited to, the pathophysiology of leukoencephalopathies, mechanistic factors behind malformations of cortical development, and comparison of manual vs. digital pathology methods in interpreting immunohistochemical indices.
Authors
Jacob A. Houpt 1, Robert R. Hammond 1
1 Department of Pathology and Laboratory Medicine, London Health Sciences Centre, London, ON, Canada.
Target Audience:
CanMEDS:
Medical Expert (the integrating role), Collaborator, Health Advocate, Scholar
Cost-Benefit Analysis of Fluorescence in Situ Hybridization Testing in the Diagnosis of IDH-Mutant 1p/19q-Codeleted Oligodendrogliomas
Abstract
Fluorescence in situ hybridization (FISH) testing has long served as a diagnostic cornerstone in confirming codeletion of the 1p and 19q chromosome arms in IDH-mutant 1p/19q-codeleted oligodendrogliomas; a test necessary to distinguish the entity from other diffuse adult-type gliomas. However, FISH is both costly and time-consuming relative to other ancillary tests such as next generation sequencing (NGS), requiring expensive fluorescent probes, specialized microscopy suites, and manual evaluation/counting by dedicated medical lab technologists (MLTs). As institutions such as London Health Sciences Centre (LHSC) proceed to validate NGS copy number variation assessment in place of direct FISH testing for the evaluation of 1p/19q-codeletion in gliomas, we reviewed all 1p/19q cytogenetic test results at our institution to better contextualize FISH testing in terms of cost-benefit ratio (CBR). From 2010 to 2024, 700 cytogenetics cases reporting 1p/19q-codeletion were retrieved. Of these, 171 were positive for codeletion of 1p/19q (24.4%). Repeat testing was requested in 25 cases (3.6%) due to borderline results and/or increased clinical suspicion, yielding a different diagnosis in at least 3 cases. Conservative estimates of the per case cost of FISH testing (including facility/equipment, reagents, and MLT labour/time) total at least $1400 CAD. While its CBR is comparable to other oncological investigations and can be less expensive than NGS on a per test basis, NGS is often ordered in conjunction to facilitate confirmation of IDH mutations and therefore is poised to save considerable time and cost if all but borderline cases of 1p/19q-codeletion can be elucidated without undertaking cytogenetic evaluation via FISH.
References
DOI: 10.1002/14651858.CD013387.pub2
DOI: 10.3390/biomedicines10123029
DOI: 10.3390/diagnostics11091702