RET (NSCLC) Test
About RET (NSCLC) Test
| Field | Value |
|---|---|
| Also Known As | RET Fusion Test, RET Gene Rearrangement Test, RET FISH Test |
| Sample Type | FFPE Tissue Block (formalin-fixed paraffin-embedded tumour tissue) |
| Fasting Required | No |
| Report Time | 8 Days |
| Recommended For | Adults diagnosed with non-small cell lung cancer (NSCLC), particularly adenocarcinoma; all genders |
| Price | Starting at ₹8,400 |
What is a RET (NSCLC) Test?
The RET (NSCLC) test detects abnormal changes in the RET gene within lung tumour tissue. RET stands for "rearranged during transfection", a gene that, when fused with another gene, can drive the growth of certain lung cancers. Doctors order this test after a diagnosis of non-small cell lung cancer to understand the tumour's genetic make-up.
The sample used is a formalin-fixed paraffin-embedded (FFPE) tissue block, obtained from a previous biopsy or surgical procedure. This test is also referred to as the RET Fusion test or the RET Gene Rearrangement test.
What Does a RET (NSCLC) Test Measure?
The NSCLC test examines tumour tissue using the FISH (fluorescence in situ hybridisation) method to identify specific genetic changes. The table below outlines what the test looks for.
| Parameter | What It Detects |
|---|---|
| RET Gene Rearrangement Status | Whether the RET gene has fused abnormally with a partner gene, driving uncontrolled cell growth |
| Fusion Partner Identification | While a FISH test confirms the presence of a fusion, global data shows the most common partners are KIF5B (70% to 80% of cases) and CCDC6 (about 20% of cases) |
This is a qualitative test. Results are reported as either positive (fusion detected) or negative (no fusion detected), not as a numerical value.
Why is a RET (NSCLC) Test Done?
The RET (NSCLC) test is an important step in understanding your lung cancer at a genetic level. It helps your oncologist choose the most appropriate treatment path.
Common Symptoms That May Require This Test
This test is not ordered based on symptoms alone. It is requested after an NSCLC diagnosis is confirmed. However, the symptoms that typically lead to the initial lung cancer investigation include:
- Persistent cough that does not improve
- Shortness of breath during normal activity
- Chest pain or discomfort
- Coughing up blood (hemoptysis)
- Unexplained weight loss
- Unusual fatigue or tiredness
- Recurrent respiratory infections
Conditions This Test Can Help Detect
Once ordered, the NSCLC test helps identify the following:
- RET fusion-positive non-small cell lung cancer, most often of the adenocarcinoma subtype
- Eligibility for targeted RET inhibitor therapy, such as selpercatinib or pralsetinib
- Tumours driven by specific gene partners including KIF5B, CCDC6, and NCOA4
RET (NSCLC) Test for Chronic Disease Monitoring
In patients with recurrent or metastatic breast cancer, the ER/PR test may be repeated because tumour receptor status can shift over time. Retesting helps clinicians understand how a cancer is behaving and whether the current treatment approach remains appropriate. This is supported by established oncology guidelines and is a standard part of managing advanced breast cancer.
How to Prepare and What to Expect
No special preparation is needed on the day of the test. However, it is important to ensure the right tissue material is available and that you bring the necessary documents.
Do You Need to Fast?
No fasting is required for this test. The sample is a tumour tissue block, not a blood sample, so your diet on the day of submission does not affect the result.
Practical Tips Before Your Test
A few steps will help ensure the process goes smoothly:
- Bring a detailed clinical history, including your symptoms, previous test results, and family history
- Carry all previous pathology reports, biopsy records, and imaging studies so the laboratory can select the right specimen
- Confirm that the FFPE tissue block from your biopsy or surgical procedure is available and has been preserved correctly
- Ensure the tissue block contains at least 20% tumour cell content, as this is typically required for accurate analysis
- Ask your oncologist or surgeon if you are unsure whether your existing tissue sample is suitable
Step-by-Step Procedure
Here is what happens from sample submission to report delivery:
- Your doctor identifies the FFPE tissue block from your previous biopsy or surgical resection and arranges its transfer to the laboratory
- The block is received by the Lupin Diagnostics team and stored at ambient temperature (18 to 28 degrees Celsius) as required
- Laboratory technicians process the tissue and apply the FISH method to examine the RET gene for abnormal fusions
- A trained pathologist reviews the FISH signals under a fluorescence microscope and interprets the findings
- A detailed report is prepared and delivered within 8 days of sample receipt
- Your oncologist reviews the report with you and discusses the next steps in your treatment plan
Factors That Can Affect Accuracy
Several factors can influence the reliability of your result:
- Insufficient tumour cell content in the tissue block
- Poor quality of tissue fixation or preservation during the original biopsy
- Degraded or inadequately processed FFPE material
- Experience and expertise of the interpreting pathologist
- Rare technical limitations of FISH, which may occasionally produce false-positive signals
Understanding Your RET (NSCLC) Test Results
Your results will show whether a RET gene fusion was detected in your tumour tissue. The table below explains what each outcome generally means.
| Parameter | Result | Interpretation |
|---|---|---|
| RET Gene Rearrangement | Negative / Not Detected | No RET fusion found; patient is not a candidate for RET-targeted therapy |
| RET Gene Rearrangement | Positive / Detected | RET fusion identified; patient may be eligible for targeted RET inhibitor treatment |
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
The testing method used can affect how results are interpreted. FISH analysis may occasionally produce false-positive signals. Studies show that, of cases identified as rearranged by FISH, only a proportion are confirmed as functional RET fusions when re-tested using next-generation sequencing (NGS). Your oncologist may recommend confirmatory testing if your result is unexpected or inconclusive.
Liquid biopsy, which analyses circulating tumour DNA from a blood sample, can detect RET fusions in cases where tissue is unavailable. However, its sensitivity depends on the amount of tumour DNA circulating in the blood at the time of testing.
Managing Your Diagnostic Journey
Since this is a cancer-related genetic test rather than a routine wellness check, the following guidance applies:
- Ensure your oncologist reviews all molecular test results, including the RET (NSCLC) test, before any treatment decision is made
- Attend all follow-up appointments so your treatment response can be tracked over time
- Discuss any new or worsening symptoms promptly with your treating doctor
Lupin Diagnostics RET (NSCLC) Test Price
The NSCLC test cost at Lupin Diagnostics starts at ₹8,400. This test requires a visit to a Lupin Diagnostics centre or the submission of your FFPE tissue block through your treating hospital.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 8400 |
| CHENNAI | 8400 |
| HYDERABAD | 8400 |
| KOLKATA | 8400 |
| NAVI MUMBAI | 8400 |
| PUNE | 8400 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
The NSCLC test online booking process at Lupin Diagnostics is straightforward:
- Select the RET (NSCLC) Test on the Lupin Diagnostics website
- Choose your city and preferred centre location
- Visit the centre at your scheduled time, or arrange submission of your FFPE tissue block as advised by your doctor or the centre team
- Receive your report via email or WhatsApp within 8 days of sample receipt
Frequently Asked Questions
The RET gene normally helps regulate cell growth. In some lung cancers, it fuses abnormally with another gene, producing a protein that causes cells to multiply without control. Detecting this fusion is important because it identifies patients who may respond well to specific targeted drugs.
This test is recommended for patients who have been diagnosed with non-small cell lung cancer, particularly the adenocarcinoma subtype. It is a standard part of molecular profiling for advanced or metastatic NSCLC, as multiple targeted therapies are now available based on test results.
The test requires an FFPE tissue block, which is a preserved tumour tissue sample from a biopsy or surgical procedure. In most cases, the block from your original diagnostic biopsy can be used, so no additional biopsy is needed.
A positive result means that a RET gene fusion was detected in your tumour. This makes you potentially eligible for targeted RET inhibitor therapy. Your oncologist will review the result alongside your overall clinical picture to plan the most suitable treatment.
RET fusions are found in approximately 1 to 2% of non-small cell lung cancer cases. Although relatively uncommon, they are considered a highly actionable finding because effective targeted treatments are available specifically for this group.
At Lupin Diagnostics, results for the RET (NSCLC) test are delivered within 8 days of sample receipt. The FISH method used here has a defined turnaround time, and your oncologist will be notified once the report is ready.
Yes, your oncologist may recommend repeat molecular testing if your cancer progresses or stops responding to current treatment. Tumour genetics can change over time, and updated testing helps guide decisions about alternative therapies.
RET (NSCLC) Test
