Challenges and Limitations in Molecular Testing of Resected Non-Small Cell Lung Cancer Specimens.

Non-small cell lung cancer (NSCLC) accounts for nearly 85% of lung cancer cases and remains a leading cause of cancer-related mortality worldwide. Advances in molecular diagnostics and targeted therapies have transformed treatment paradigms, yet the integration of molecular testing into routine care for resected NSCLC specimens continues to face significant challenges. This review outlines the technical, clinical, and systemic barriers that limit the effectiveness of molecular testing. Key considerations include tissue quality, the limitations of formalin-fixed paraffin-embedded (FFPE) samples, and the comparative roles of conventional methods-such as immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and reverse transcription polymerase chain reaction (RT-PCR)-versus next-generation sequencing (NGS). We also discuss the prevalence and clinical relevance of common genomic alterations, including TP53, KRAS, EGFR, and ALK, as well as their impact on prognosis and treatment selection. Real-world obstacles such as accessibility, reimbursement, delays in testing, interdisciplinary coordination, and sample adequacy are critically examined. Emerging innovations-including multi-omics integration, spatial profiling, liquid biopsy, artificial intelligence, and novel targeted therapies-offer opportunities to overcome current limitations and improve patient outcomes. Finally, practical recommendations are proposed to optimize tissue handling, testing algorithms, and access to precision-guided therapies. By addressing these challenges, molecular testing in NSCLC can be more effectively leveraged to personalize treatment strategies and enhance survival outcomes.