ROS1 status (Lung Cancer)

Methodology

To determine the ROS1 status in non-small-cell lung cancer (NSCLC), a validated ROS1 IHC test is used as a first screening method (1). Patient samples that show ROS1 IHC overexpression in the tumour cells are subsequently subjected to ROS1 FISH analysis for confirmation of a positive ROS1 status (2).

ROS1 IHC testing is performed using the Cell Signalling Technology anti-ROS1 (D4D6) Rabbit monoclonal primary antibody used in combination with the OptiView DAB IHC Detection kit and OptiView Amplification Kit as a fully automated immunohistochemistry assay on the Ventana BenchMark Ultra automated slide stainer.

ROS1 FISH testing is performed using the Vysis 6q22 ROS1 Break apart FISH probe (Abbott, RUO).

Clinical Implication

To determine the ROS1 status in non-small-cell lung cancer (NSCLC), a validated ROS1 IHC test is used as a first screening method (1). Patient samples that show ROS1 IHC overexpression in the tumour cells are subsequently subjected to ROS1 FISH analysis for confirmation of a positive ROS1 status (2).

ROS1 IHC testing is performed using the Cell Signalling Technology anti-ROS1 (D4D6) Rabbit monoclonal primary antibody used in combination with the OptiView DAB IHC Detection kit and OptiView Amplification Kit as a fully automated immunohistochemistry assay on the Ventana BenchMark Ultra automated slide stainer.

ROS1 FISH testing is performed using the Vysis 6q22 ROS1 Break apart FISH probe (Abbott, RUO).

Specimen Requirements

Acceptable specimens for the assay are formalin (10% buffered or Zinc formalin)-fixed (6-48 hours), paraffin-embedded NSCLC tissue specimens. Sectioned slides must be analysed within 3 months after sectioning date. 

Volume

1 representative paraffin block is preferred. Alternatively, 5 unstained freshly sectioned tissue sections are accepted (1 slide of 4 or 5 µm thickness for H&E staining, a minimum of 2 slides of 4-5 µm thickness for ROS1 IHC testing and a minimum of 2 slides of 3 µm thickness for ROS1 FISH testing).

Storage and Shipment Instructions

Maintain and ship specimens at ambient temperature.

Limitations

Fixatives other than buffered formalin, prolonged fixation time or exposure to severe heath or chemicals may give rise to inadequate results.

Special Requirements

None

Turn-Around Time

Five to 7 business days for slides and paraffin blocks respectively. If confirmation by FISH is required: additional 5 to 7 business days. 

References

  1. Bubendorf L et al. Testing for ROS1 in non-small cell lung cancer: a review with recommendations. Virchows Arch. 2016, 469(5): 489-503.
  2. Sholl LM et al. ROS1 immunohistochemistry for detection of ROS1-rearranged lung adenocarcinomas. Am J Surg Pathol. 2013, 37(9):1441-9.
  3. Davies KD et al. Molecular pathways: ROS1 fusion proteins in cancer. Clin Cancer Res. 2013, 19(15):4040-5.
  4. Shaw AT et al. Crizotinib in ROS1-rearranged non-small-cell lung cancer. N Engl J Med. 2014 371(21):1963-71.

Updated on 09 April 2019