Roche Tissue Diagnostics, Tucson, Ariz, has announced the global launch of its Ventana ROS1 (SP384) rabbit monoclonal primary antibody, the first in vitro diagnostic ROS1 immunohistochemistry (IHC) assay. ROS1-positive cancer cases are predominantly found among younger nonsmokers and account for 1% to 2% of all cases of non-small cell lung cancer (NSCLC).1

The antibody test detects the presence of ROS1 protein in tissue and may be useful in identifying ROS1-positive cancer cases. Guidelines from the College of American Pathologists and the National Comprehensive Cancer Network recommend ROS1 testing for confirmed lung adenocarcinoma cases.2,3 As these types of cancer are rare—found in up to 2% of non-small cell lung cancer cases—the use of a ROS1 IHC biomarker may provide a cost-effective and efficient means of identifying cases with elevated ROS1 protein expression before confirming by another method, such as fluorescence in situ hybridization or next-generation sequencing.4

“Our highly sensitive ROS1 test is the first in vitro diagnostic IHC available for recommended lung cancer testing guidelines, with the added benefit of rapid turnaround time,” says Jill German, head of Roche Tissue Diagnostics. “While this is important in non-small cell lung cancer cases today, ROS1 is also being investigated in a number of clinical trials in other cancer types.”

Jill German, Roche Tissue Diagnostics.

Jill German, Roche Tissue Diagnostics.

Elevated ROS1 protein expression in tumor cells may indicate the presence of a ROS1 gene rearrangement.As with NSCLC tumors that are positive for anaplastic lymphoma kinase (ALK), ROS1-positive lung tumors arise predominantly in younger, nonsmoking individuals.1  This is of particular significance, as some ALK inhibitors have also been shown to be active in tumors harboring a ROS1 rearrangement.

Interest in identifying ROS1-positive cancer cases has increased in recent years, with clinical trials investigating the response of cancers harboring a ROS1 rearrangement of tyrosine kinase inhibitors, targeted against ALK rearrangements.5

Lung cancer causes more than three deaths every minute and is the most common cancer worldwide.Each year, an estimated 2.1 million people are diagnosed with the disease.Lung cancer is divided into two main subtypes: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Up to 85% of all lung cancers are NSCLC, which can be further subtyped into adenocarcinoma, large cell carcinoma, and squamous cell carcinoma.7

The need for accurate classification of these subtypes has been amplified with the introduction of targeted therapies.Targeted therapies have shifted the lung cancer treatment paradigm away from being based only on histological subtype, to incorporating subtyping involving oncogenic mutations and fusions.9

The Ventana ROS1 (SP384) rabbit monoclonal primary antibody is available for use on Roche’s BenchMark series of automated staining instruments. For further information, visit Roche.


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Featured image:

Ventana ROS1 (SP384) rabbit monoclonal primary antibody IHC staining of lung adenocarcinoma tissue.