FISH - ROS Gene Rearrangement Test: Booking, Price, and Results
About FISH - ROS Gene Rearrangement Test: Booking, Price, and Results
| Field | Value |
|---|---|
| Also Known As | ROS1 Rearrangement FISH, ROS1 Fusion by FISH, ROS1 Gene Test, ROS1 Gene Assay, ROS1 (6q22) Rearrangement FISH |
| Sample Type | Tumour tissue (formalin-fixed, paraffin-embedded tissue block or unstained tissue slides) |
| Fasting Required | No |
| Report Time | 9 Days |
| Recommended For | Adults with suspected or confirmed non-small cell lung cancer (NSCLC), particularly adenocarcinoma; all genders |
| Price | Starting at ₹7,000 |
What is a FISH - ROS Gene Rearrangement Test?
The FISH - ROS gene Rearrangement Test detects abnormal changes in the ROS1 gene located on chromosome 6q22. It uses a laboratory technique called fluorescence in situ hybridisation (FISH) to identify whether parts of the ROS1 gene have broken apart and fused with another gene. Doctors typically order this test for patients diagnosed with non-small cell lung cancer (NSCLC) to guide treatment decisions. The test is also known as ROS1 Rearrangement FISH or the ROS1 Gene Test.
What Does a FISH - ROS Gene Rearrangement Test Measure?
This test analyses tumour tissue at the genetic level to detect specific changes in the ROS1 gene. The following components are examined during the analysis.
| Component | What It Detects |
|---|---|
| ROS1 gene rearrangement | Abnormal chromosomal changes where ROS1 breaks apart and joins with a partner gene |
| Break-apart FISH pattern | Separation of two differently coloured probes indicating a gene rearrangement |
| Common fusion partners | Partner genes such as CD74, EZR, SDC4, and SLC34A2 that fuse with ROS1 |
A result is considered positive when 15% or more of the tumour cells examined show split signals, meaning the two ends of the ROS1 gene have separated.
Why is a FISH - ROS Gene Rearrangement Test Done?
This test plays a key role in determining whether a patient with lung cancer is eligible for targeted therapy. It helps identify a specific genetic change that points to a particular type of treatment.
Common Symptoms That May Require This Test
A doctor may order this test when a patient presents with symptoms associated with advanced lung cancer. Common symptoms include the following.
- Persistent or worsening cough
- Shortness of breath
- Chest pain or discomfort
- Unexplained weight loss
- Coughing up blood
- Fatigue and loss of appetite
- Recurrent lung infections
- Unexplained hoarseness
Conditions This Test Can Help Detect
The test helps identify the following conditions.
- ROS1-positive NSCLC: Gene rearrangements in ROS1 occur in 1 to 2% of non-small cell lung cancers and may indicate eligibility for targeted drug therapy
- Inflammatory myofibroblastic tumours: A rare type of soft tissue tumour where ROS1 rearrangements have been identified
- Certain skin tumours: Specific cutaneous melanocytic tumours (tumours involving pigment-producing skin cells) have also shown ROS1 rearrangements
ROS1 rearrangements are seen more often in younger patients, those who have never smoked, women, and patients with adenocarcinoma at an advanced stage.
How to Prepare and What to Expect
This test uses tumour tissue collected during a prior biopsy or surgical procedure, so there is no additional sample collection required from the patient at the time of booking.
Do You Need to Fast?
No fasting is required for this test. The test is performed on tumour tissue, not a blood or urine sample.
Practical Tips Before Your Test
Please keep the following points in mind before submitting the sample.
- Bring a detailed clinical history, including your symptoms, previous test results, and details of your cancer diagnosis, as this is required for the test
- Ensure the tissue block is a formalin-fixed, paraffin-embedded (FFPE) tumour tissue block, or submit unstained tissue slides as specified by your doctor
- A pathology report confirming the tumour origin should accompany the specimen
- Inform your doctor if the tissue was decalcified (treated to remove calcium deposits), as this may affect the test outcome
- Store the paraffin block away from excessive heat and keep it at room temperature during transport
Step-by-Step Procedure
The FISH - ROS gene Rearrangement Test procedure involves the following steps.
- A pathologist reviews the haematoxylin and eosin (H&E) stained tissue slide and identifies the tumour area to be analysed.
- The paraffin-embedded tissue is cut into very thin sections (5 microns thick) and mounted on glass slides.
- A dual-colour FISH probe is applied to the tissue. This probe attaches to both ends of the ROS1 gene using two different coloured markers.
- The laboratory examines approximately 50 tumour cell nuclei under a fluorescence microscope to look for split signal patterns.
- The pathologist interprets the signal patterns and prepares a detailed report.
- The completed report is delivered within the turnaround time confirmed at booking.
Factors That Can Affect Accuracy
Several factors can influence the reliability of results.
- Use of fixatives other than standard formalin (such as Prefer or Bouin's solution) may reduce test success
- Decalcified tissue has a lower success rate of around 50% with FISH analysis
- Insufficient tumour tissue in the submitted sample may prevent analysis
- Improper storage or handling of the tissue block before submission
- Complex signal patterns may require additional testing by next-generation sequencing (NGS)
Understanding Your FISH - ROS Gene Rearrangement Test Results
Results from this test are qualitative, meaning the outcome is reported as positive or negative rather than a numerical value. Your oncologist will interpret the result alongside your full clinical picture.
| Result | Interpretation |
|---|---|
| Negative (no rearrangement) | No ROS1 gene rearrangement detected in the tumour cells examined |
| Positive (rearrangement present) | ROS1 gene rearrangement detected; may indicate eligibility for targeted therapy |
Disclaimer: These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Certain situations can affect how results should be read.
A negative result does not completely rule out the presence of a ROS1 fusion. Your doctor may recommend additional testing, such as NGS, if clinical suspicion remains high.
This test also does not detect other chromosomal abnormalities unrelated to ROS1. Complex signal patterns falling below the 15% cutoff may require confirmatory testing before a conclusion is reached.
How to Maintain Healthy Levels
This test identifies a genetic change in tumour tissue and is not influenced by lifestyle choices. However, the following general points apply.
- Discuss all results with your oncologist for a complete picture of your treatment options
- ROS1 rearrangements are more commonly seen in people who have never smoked, reinforcing the value of avoiding tobacco use
- Attend all follow-up appointments as recommended by your cancer care team
Lupin Diagnostics FISH - ROS Gene Rearrangement Test Price
The FISH - ROS gene Rearrangement Test cost at Lupin Diagnostics starts at ₹7,000. This test requires a visit to a Lupin Diagnostics centre or collection point; home collection is not available for this test.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 7000 |
| CHENNAI | 7000 |
| HYDERABAD | 7000 |
| KOLKATA | 7000 |
| NAVI MUMBAI | 7000 |
| PUNE | 7000 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Follow these steps to book your FISH - ROS gene Rearrangement Test online booking through Lupin Diagnostics.
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time for sample submission with your FFPE tissue block and clinical history.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
The FISH - ROS gene Rearrangement Test uses a technique called fluorescence in situ hybridisation to detect abnormal changes in the ROS1 gene within tumour tissue. It helps identify patients with lung cancer who may respond to specific targeted drugs. The test is performed on tissue collected during a previous biopsy or surgery.
This test is typically recommended for patients diagnosed with advanced non-small cell lung cancer, particularly adenocarcinoma, who have tested negative for other common mutations such as EGFR and ALK rearrangements. Your oncologist will advise whether this test is appropriate for your case.
ROS1 gene rearrangements occur in approximately 1 to 2% of non-small cell lung cancers. They are more common in younger patients, those who have never smoked, and those with adenocarcinoma at an advanced stage.
A positive result indicates that the ROS1 gene has rearranged and fused with a partner gene in the tumour cells. This may mean you are eligible for targeted treatment. Your oncologist will discuss the next steps based on the full clinical picture.
The test uses tumour tissue already collected during a biopsy or surgical procedure. The tissue block should be fixed in formalin and embedded in paraffin (FFPE). You do not need to undergo a separate procedure for this test.
Yes, a negative result does not always rule out a ROS1 fusion. The test has certain technical limitations, and your doctor may recommend further testing using next-generation sequencing if clinical suspicion remains high.
The report turnaround time at Lupin Diagnostics is 9 days. Timelines may vary slightly depending on the condition of the submitted tissue sample and laboratory scheduling.
FISH - ROS Gene Rearrangement Test: Booking, Price, and Results
