2021 World Conference on Lung Cancer (Posters)-FP12. Lung Adenocarcinomas with ROS1 Rearrangement show Diffuse Strong ROS1 Immunohistochemical Staining

FP12. Lung Adenocarcinomas with ROS1 Rearrangement show Diffuse Strong ROS1 Immunohistochemical Staining

Video Transcription

Video Summary

The presenter discusses the use of ROS1 IHC and FISH testing in lung adenocarcinomas to identify those with ROS1 rearrangements. They conducted a study on 187 cases and found that cases with strong, diffuse ROS1 IHC staining were positive for ROS1 rearrangement by FISH, while cases with weak, patchy staining were negative. They suggest using an H-score, which combines staining intensity and percentage of positive tumor cells, to determine which cases should undergo FISH testing. They recommend applying an H-score cutoff of ≥200 for sensitivity and specificity in identifying ROS1 rearranged cases. They also raise the issue of false negative FISH results and suggest further investigation using next-generation sequencing fusion panels.

Asset Subtitle

Timothy Fielder

Meta Tag

Speaker Timothy Fielder

Topic Predictive Tumor Based Assays/ Biomarkers/ Pathology

Keywords

ROS1 IHC

FISH testing

lung adenocarcinomas

ROS1 rearrangements

H-score