Test ID ROS1F Lung Cancer, ROS1 (6q22) Rearrangement, FISH, Tissue
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. A pathology report is required in order for testing to be performed. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports.
2. A reason for testing must be provided. If this information is not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Tissue
Preferred: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.
Acceptable: Slides
Slides: Four consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Secondary ID
35845Useful For
Identifying c-ros oncogene 1 (ROS1) gene rearrangements in patients with late-stage, lung adenocarcinomas that are negative for epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
_I099 | Interphases, 25-99 | No, (Bill Only) | No |
_I300 | Interphases, >=100 | No, (Bill Only) | No |
_IL25 | Interphases, <25 | No, (Bill Only) | No |
_PADD | Probe, +1 | No, (Bill Only) | No |
_PB02 | Probe, +2 | No, (Bill Only) | No |
_PB03 | Probe, +3 | No, (Bill Only) | No |
_PBCT | Probe, +2 | No, (Bill Only) | No |
Testing Algorithm
This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge.
This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results.
Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
ROS1 (6q22), FISH, TsSpecimen Type
TissueSpecimen Minimum Volume
Two consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Tissue | Ambient (preferred) | |
Refrigerated |
Clinical Information
Lung cancer is the leading cause of cancer mortality in developed countries. The discovery of a variety of genetic alterations in non-small-cell lung cancer (NSCLC) has enabled the use of targeted therapy such as the anaplastic lymphoma kinase (ALK) inhibitor, crizotinib, and the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, erlotinib, for NSCLC with ALK rearrangements and EGFR mutations, respectively.
The c-ros oncogene 1 (ROS1), originally described in glioblastomas, has been identified as a potential relevant therapeutic target in lung adenocarcinoma. Crizotinib has shown in vitro activity and early evidence of clinical activity in ROS1-rearranged tumors.
Reference Values
An interpretive report will be provided.
Cautions
This test is not approved by the U.S. Food and Drug Administration, and it is best used as an adjunct to existing clinical and pathologic information.
Fixatives other than formalin (eg, Prefer, Bouin) may not be successful for FISH assays, however, nonformalin-fixed samples will not be rejected.
Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysPerforming Laboratory

Test Classification
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
88271x2, 88291-DNA probe, each (first probe set), Interpretation and report
88271x2-DNA probe, each; each additional probe set (if appropriate)
88271x1-DNA probe, each; coverage for sets containing 3 probes (if appropriate)
88271x2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)
88271x3-DNA probe, each; coverage for sets containing 5 probes (if appropriate)
88274 w/modifier 52-Interphase in situ hybridization, <25 cells, each probe set (if appropriate)
88274-Interphase in situ hybridization, 25 to 99 cells, each probe set (if appropriate)