Huang RSP Smith D Le CH Liu WW Ordinario E Manohar C Lee M Rajamani J Truong H Li J Choi C Li J Pati A Bubendorf L Buettner R Kerr KM Lopez-Rios F Marchetti A Marondel I Nicholson AG Öz AB Pauwels P Penault-Llorca F Rossi G Thunnissen E Newell AH Pate G Menzl I 2020 CONTEXT.— The ability to determine ROS1 status has become mandatory for patients with lung adenocarcinoma, as many global authorities have approved crizotinib for patients with ROS1-positive lung adenocarcinoma. OBJECTIVE.— To present analytical correlation of the VENTANA ROS1 (SP384) Rabbit Monoclonal Primary Antibody (ROS1 [SP384] antibody) with ROS1 fluorescence in situ hybridization (FISH). DESIGN.— The immunohistochemistry (IHC) and FISH analytical comparison was assessed by using 122 non-small cell lung cancer samples that had both FISH (46 positive and 76 negative cases) and IHC staining results available. In addition, reverse transcription-polymerase chain reaction (RT-PCR) as well as DNA and RNA next-generation sequencing (NGS) were used to further examine the ROS1 status in cases that were discrepant between FISH and IHC, based on staining in the cytoplasm of 2+ or above in more than 30% of total tumor cells considered as IHC positive. Here, we define the consensus status as the most frequent result across the 5 different methods (IHC, FISH, RT-PCR, RNA NGS, and DNA NGS) we used to determine ROS1 status in these cases. RESULTS.— Of the IHC scoring methods examined, staining in the cytoplasm of 2+ or above in more than 30% of total tumor cells considered as IHC positive had the highest correlation with a FISH-positive status, reaching a positive percentage agreement of 97.8% and negative percentage agreement of 89.5%. A positive percentage agreement (100%) and negative percentage agreement (92.0%) was reached by comparing ROS1 (SP384) using a cutoff for staining in the cytoplasm of 2+ or above in more than 30% of total tumor cells to the consensus status. CONCLUSIONS.— Herein, we present a standardized staining protocol for ROS1 (SP384) and data that support the high correlation between ROS1 status and ROS1 (SP384) antibody. application/pdf https://sonar.ch/global/documents/130403 eng info:eu-repo/semantics/altIdentifier/doi/10.5858/arpa.2019-0085-OA info:eu-repo/semantics/altIdentifier/pmid/31509456 info:eu-repo/semantics/openAccess Archives of pathology & laboratory medicine. - 2020 Biomarkers, Tumor Carcinoma, Non-Small-Cell Lung Humans Immunohistochemistry In Situ Hybridization, Fluorescence Lung Neoplasms Oncogene Proteins, Fusion Protein-Tyrosine Kinases Proto-Oncogene Proteins Correlation of ROS1 Immunohistochemistry With ROS1 Fusion Status Determined by Fluorescence In Situ Hybridization. http://purl.org/coar/resource_type/c_6501