HER2 Testing Strategies, IHC Interpretation, and Tissue Stewardship in NSCLC

In this episode, Dr Julia Rotow explores the expanding role of HER2 testing in NSCLC and the practical challenges that arise as therapeutic options increase. She reviews how HER2 IHC 3+ overexpression is assessed in lung cancer using gastric scoring criteria, distinguishing this approach from breast cancer–specific algorithms. Dr Rotow summarizes available efficacy data for HER2-directed ADCs in HER2-overexpressing NSCLC and explains how these findings help inform treatment selection when IHC 3+ is present alongside genomic HER2 alterations. The discussion then broadens to cover tissue stewardship, including strategies for prioritizing next-generation sequencing, integrating key IHC markers, and determining when rebiopsy may be necessary. Dr Rotow emphasizes how rapidly evolving standards require clinicians to ensure that biomarker profiles remain current, especially for patients who respond to frontline therapies for prolonged periods.