IHC Marker - ERG/P55 Test
About IHC Marker - ERG/P55 Test
| Field | Value |
|---|---|
| Also Known As | ERG IHC, ERG Immunostain, P55 Marker, ETS-related gene marker, ERG oncoprotein test |
| Sample Type | Formalin-fixed, paraffin-embedded (FFPE) tissue block |
| Fasting Required | No. This test uses tissue samples, not blood |
| Report Time | 3 days |
| Recommended For | Males (primarily for prostate evaluation); all genders for vascular tumour assessment |
| Price | Starting at ₹1,920 |
What is an IHC Marker - ERG/P55 Test?
The ERG/P55 test is a specialised tissue-based test that detects the presence of the ERG protein in a biopsy or surgical specimen. It uses a laboratory technique called immunohistochemistry (IHC), in which specific antibodies are applied to a tissue slice to detect the presence of the ERG protein.
Doctors most commonly request this test when evaluating a prostate tissue sample or when a vascular (blood vessel) tumour is suspected. The P55 marker is assessed alongside ERG to support a more complete tissue diagnosis.
What Does an IHC Marker - ERG/P55 Test Measure?
This test examines tissue at the cellular level to detect the expression of specific proteins. Below are the key markers evaluated.
| Marker | What it Detects | Why it Matters |
|---|---|---|
| ERG protein | Expression of the ETS-related gene product in cell nuclei | Highly specific for prostate cancer and endothelial (blood vessel lining) cells |
| P55 marker | Protein expression pattern in the tissue sample | Supports diagnosis when assessed together with ERG |
Why is an IHC Marker - ERG/P55 Test Done?
This test is requested when a tissue sample needs to be examined for signs of certain cancers or tumour types. It helps a pathologist reach a more accurate diagnosis.
Common Symptoms That May Require This Test
A doctor may request this test based on clinical findings or biopsy results. Common indications include:
- Elevated PSA (prostate-specific antigen) levels on a blood test
- Abnormal findings on a digital rectal examination
- A suspicious or inconclusive prostate biopsy result
- Suspected vascular tumour identified on imaging or initial tissue examination
- Metastatic cancer where the site of origin is unknown
- Confirmation of a tissue diagnosis before starting treatment
Conditions This Test Can Help Detect
The ERG/P55 IHC marker test can assist in assessing several conditions. These include:
- Prostate cancer, particularly cases involving the TMPRSS2-ERG gene fusion, which occurs in approximately 40 to 65% of prostate cancers
- Vascular tumours such as angiosarcoma, epithelioid haemangioendothelioma, and Kaposi sarcoma
- Haemangioma and lymphangioma (benign vascular growths)
- Acute myeloid leukaemia and lymphoblastic leukaemia, where ERG overexpression has been reported
- A subset of Ewing sarcomas involving ERG-related chromosomal changes
How to Prepare and What to Expect
Preparation for this test is minimal from the patient's side, as the sample is tissue rather than blood. The key responsibility is to ensure the tissue is properly collected and processed.
Do You Need to Fast?
No fasting is required. This test does not use a blood or urine sample, so there are no dietary restrictions before the test.
Practical Tips Before Your Test
The following points help ensure the test can be performed without delay.
- Bring a detailed clinical history, including your symptoms, previous test results, and any prior biopsy or histopathology reports, as this is required for the test
- Inform your doctor about any medications you are taking, as some may affect tissue quality
- Ask your treating doctor or surgeon to label the sample clearly with your details and clinical information
Step-by-Step Procedure
The ERG/P55 test procedure involves several laboratory steps following tissue sample collection.
- A clinician collects the tissue sample via needle biopsy or surgical excision from the relevant site (e.g., prostate gland or suspected tumour).
- The tissue is placed in formalin to preserve it, then embedded in a paraffin wax block to create the FFPE tissue block.
- The paraffin block is sliced into very thin sections (approximately 4 micrometres thick) and mounted onto glass slides.
- The slides undergo antigen retrieval, a process that unmasks the protein-binding sites within the tissue.
- ERG-specific and P55-specific antibodies are applied to the slides, incubated, and then visualised using a colour-producing stain (chromogen).
- A qualified pathologist examines the stained slides under a microscope and interprets the staining pattern to produce a report.
Factors That Can Affect Accuracy
Several factors may influence the reliability of the test result.
- Insufficient fixation time or improper formalin concentration when preserving the tissue
- A tissue sample that is too small or poorly representative of the lesion
- Delayed fixation of the biopsy specimen after collection
- Suboptimal antigen retrieval technique during processing
- An inadequate clinical history was provided with the sample
Understanding Your IHC Marker - ERG/P55 Test Results
Results from this test are reported by a pathologist as positive or negative based on the observed staining pattern. Your treating doctor will review the findings together with your clinical history and other test results.
| Result | Interpretation |
|---|---|
| Positive (nuclear staining) | ERG protein expression is present; this may indicate prostate cancer or a vascular tumour origin |
| Negative | ERG protein expression is absent, suggesting benign prostate tissue, non-vascular tumour, or other diagnosis |
ERG IHC has been reported to have approximately 99% specificity and 96% sensitivity for detecting prostate cancer, making it one of the more reliable markers in this setting. However, no single marker provides a complete diagnosis on its own.
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.
How to Maintain Healthy Levels
While there are no "levels" to maintain for a tissue-based test, the following general wellness tips are relevant.
- Men over 50 years of age, or those with a family history of prostate cancer, should discuss prostate cancer screening with their doctor regularly
- Maintain a balanced diet rich in vegetables and low in processed foods to support general health
- Stay physically active and attend routine health check-ups, particularly if you have known risk factors
Lupin Diagnostics IHC Marker - ERG/P55 Test Price
The ERG/P55 test cost at Lupin Diagnostics starts at ₹1,920. This test requires a visit to a Lupin Diagnostics centre, as home collection is not available for tissue-based tests of this nature.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 1920 |
| CHENNAI | 1920 |
| HYDERABAD | 1920 |
| KOLKATA | 1920 |
| NAVI MUMBAI | 1920 |
| PUNE | 1920 |
Disclaimer: Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time to submit the sample.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Frequently Asked Questions
This test detects ERG and P55 protein expression in tissue samples. It is primarily used to help diagnose prostate cancer and to identify vascular tumours such as angiosarcoma, haemangioma, and Kaposi sarcoma. Your doctor or pathologist will interpret findings alongside other clinical information.
The tissue sample is obtained through a biopsy or surgical procedure performed by a qualified clinician. This may be a needle biopsy or a surgical excision, depending on the clinical situation. The test cannot be performed on blood or urine samples.
No. This test requires a formalin-fixed, paraffin-embedded tissue block prepared from a biopsy specimen. The sample must be collected in a clinical setting by a trained medical professional and cannot be arranged as a home collection.
Not on its own. While positive ERG expression is strongly associated with prostate cancer or vascular tumours, a pathologist must interpret the result alongside other IHC markers, clinical findings, and the patient's full medical history before a diagnosis is made.
ERG detects expression of a protein linked to a specific gene fusion found in a significant proportion of prostate cancers and in vascular tumours. The P55 marker is assessed alongside ERG to provide a more complete picture of the tissue. Together, they help the pathologist reach a more accurate diagnosis.
Bring all previous histopathology reports, biopsy records, imaging results, and a detailed written clinical history. This information is required for the test and helps the pathologist interpret the findings accurately.
At Lupin Diagnostics, reports are typically available within 3 days. The timeline may vary slightly depending on the case's complexity and whether additional markers need to be assessed alongside ERG and P55.
IHC Marker - ERG/P55 Test
