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Optimizing EGFR Mutation Testing in Resource-Limited Settings: A Comparative Analysis of Diagnostic Platforms in Libya

Ahmed, A. F. F.

2026-06-29 oncology
10.64898/2026.06.25.26356534 medRxiv
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Background Lung cancer mortality is rising in Libya, but access to molecular diagnostics for EGFR mutations--essential for guiding tyrosine kinase inhibitor therapy--remains severely limited. Selecting an appropriate testing platform requires balancing analytical performance against cost and infrastructure constraints. Methods We conducted a prospective comparative validation study using formalin-fixed paraffin-embedded (FFPE) tissue samples from Libyan non-small cell lung cancer (NSCLC) patients. Following stringent DNA quality control, samples were tested in parallel across four platforms: multiplex real-time PCR (MRT-PCR), reverse hybridization strip assay (RHSA), agarose gel electrophoresis (AGE), and immunohistochemistry (IHC). Performance was assessed by inter-method concordance, turnaround time, and cost per test. Results Of 30 initial samples, only six (20%) met quality thresholds (A260/A280 1.70-1.90; concentration [≥]10 ng/{micro}L), highlighting pre-analytical challenges. Three samples harbored EGFR exon 19 deletions. A critical discordance was identified: one sample tested negative by MRT-PCR (Ct {approx}38, {Delta}Ct=13) but positive by RHSA, AGE, and IHC, indicating a false-negative result from the reference method. IHC and RHSA offered the most favorable balance of cost (USD 40-75/test) and operational feasibility, while MRT-PCR (USD 150/test) required specialized infrastructure. Conclusions Relying solely on automated PCR may lead to under-diagnosis in low-cellularity or degraded FFPE samples. We recommend a hybrid algorithm: IHC as a cost-effective primary screen, followed by RHSA for confirmation. This approach optimizes resource allocation and improves diagnostic equity in Libya.

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