IHC Marker-TAG72 Test
About IHC Marker-TAG72 Test
| Field | Value |
|---|---|
| Also Known As | TAG-72, Tumour-Associated Glycoprotein 72, CA 72-4, B72.3 Marker, TAG72 IHC |
| Sample Type | Tissue biopsy (formalin-fixed, paraffin-embedded / FFPE block) |
| Fasting Required | No — the test is performed on a tissue sample, not a blood sample |
| Report Time | 3 Days |
| Recommended For | Adults of any gender with suspected adenocarcinoma or where tumour classification is needed |
| Price | Starting at ₹1,920 |
What is an IHC Marker-TAG72 Test?
The TAG72 test is a laboratory test that analyses tumour tissue for the presence of a protein called Tumour-Associated Glycoprotein 72 (TAG-72). A pathologist uses a technique called immunohistochemistry (IHC) to detect this protein in a preserved tissue sample. The test is also known as the TAG-72 IHC or B72.3 marker test. Doctors typically order it when they need to identify the type or origin of a suspected cancer.
What Does an IHC Marker-TAG72 Test Measure?
This test detects a single protein marker in tumour tissue. The table below explains what the result indicates.
| Marker | What It Is | Why It Matters |
|---|---|---|
| TAG-72 (Tumour-Associated Glycoprotein 72) | A large protein normally found in foetal tissue that reappears in certain cancers | Helps identify gland-forming cancers (adenocarcinomas) and distinguish them from other tumour types |
TAG-72 shows up in a wide range of epithelial cancers, including those of the colon, breast, lung, ovary, pancreas, and stomach. It is rarely present in normal adult tissue, which makes it a useful marker for cancer classification.
Why is an IHC Marker-TAG72 Test Done?
Doctors order this test when a tissue sample needs further examination to determine the nature or origin of a growth. Below are the common reasons it may be requested.
Common Symptoms That May Require This Test
The following findings or symptoms often lead a doctor to request this test:
- An unexplained mass or lump detected on physical examination
- Suspicious lesions found on CT, MRI, or PET scan imaging
- Fluid around the lungs (pleural effusion) without a clear cause
- Abnormal biopsy findings that require further tumour classification
- Suspected metastatic cancer where the primary site is unknown
Conditions This Test Can Help Detect
A pathologist may use the TAG-72 IHC result to help identify or rule out the following:
- Adenocarcinomas of the colon, pancreas, stomach, ovary, breast, uterus (endometrium), and non-small cell lung
- Distinguishing lung adenocarcinoma from pleural mesothelioma (cancer of the lung lining), which typically does not express TAG-72
- Advanced colorectal cancer with possible lymph node involvement
- Apocrine carcinoma (a rare cancer with features of sweat gland cells), when used alongside other markers
- Metastatic cancers with features of epithelial origin
How to Prepare and What to Expect
Because the TAG72 test procedure is performed on a tissue block rather than a blood sample, very little preparation is needed from the patient. The notes below will help you understand what to bring and what happens during the process.
Do You Need to Fast?
No fasting is required. This test is carried out on a preserved tissue sample obtained through a biopsy, not on a blood or urine sample. If your doctor is arranging a new biopsy, they will give you separate instructions for that procedure.
Practical Tips Before Your Test
Here are a few things to keep in mind before submitting your sample:
- Bring a detailed clinical history including your symptoms, previous test results, and family history, as this is required for the test
- Carry any existing imaging reports (CT, MRI, PET) and prior pathology or biopsy reports
- If you already have a paraffin (FFPE) tissue block from a previous biopsy, it can usually be submitted directly — a fresh biopsy may not be needed
- Ensure your treating doctor clearly communicates the suspected diagnosis to the laboratory
- Inform your doctor of all medications you are currently taking, especially if a new biopsy is being planned
Step-by-Step Procedure
The following steps explain how the tissue sample is processed and analysed in the laboratory:
- A tissue sample is collected through a biopsy or surgical removal performed by your doctor at a healthcare centre.
- The tissue is preserved using formalin and then embedded in paraffin wax to maintain its structure. This creates the FFPE block that is sent to the laboratory.
- The block is sliced into very thin sections, which are placed onto microscope slides.
- Specially prepared antibodies that target TAG-72 are applied to the slides. Where the protein is present, the antibody binds to it.
- A detection system is added that produces a colour change (typically brown staining), making the protein visible under the microscope.
- A qualified pathologist examines the stained slides, interprets the staining pattern, and prepares a report.
Factors That Can Affect Accuracy
Several factors can influence the reliability of IHC results:
- Quality of tissue fixation — tissue must be fixed properly in formalin to preserve the sample
- Adequacy of the tissue sample submitted
- Correct antigen retrieval technique used during laboratory processing
- Antibody specificity — low-specificity antibodies increase the risk of false-positive or false-negative results
- Use of appropriate positive and negative controls by the laboratory
Understanding Your IHC Marker-TAG72 Test Results
Results from the TAG72 test are reported by a pathologist and must always be reviewed alongside your clinical history, imaging findings, and other test results. The table below provides a general guide to interpreting the staining outcome.
| Result | Typical Meaning |
|---|---|
| Negative (no staining) | Normal adult tissue or a tumour that does not express TAG-72 (e.g., mesothelioma, sarcoma, haematopoietic tumours) |
| Positive (cytoplasmic staining) | Suggests the presence of an adenocarcinoma or other epithelial malignancy |
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 TAG-72 staining is interpreted:
- Secretory endometrium (the womb lining during a specific phase of the menstrual cycle) may show weak reactivity, which can be misleading in gynaecological specimens.
- A small number of benign (non-cancerous) lesions of the breast and colon may show limited reactivity, so results must be read with caution.
- TAG-72 is expressed in gastrointestinal tissue during foetal development, which is relevant when interpreting specimens from neonates or foetal tissue.
How to Maintain Healthy Levels
Because this is a cancer classification test and not a routine screening tool, general lifestyle changes do not directly affect TAG-72 expression. The following steps are still worthwhile:
- Follow your doctor's recommended cancer screening schedule (such as colonoscopy or mammography) to detect any changes early.
- Report new or persistent symptoms to your doctor without delay.
- Attend all follow-up appointments as advised by your oncologist or specialist.
Lupin Diagnostics IHC Marker-TAG72 Test Price
The TAG72 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 IHC tests.
The FFPE tissue block can also be submitted directly at the centre if you already have one from a prior biopsy.
| 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
Booking the TAG72 test online at Lupin Diagnostics is straightforward:
- Select the IHC Marker-TAG72 Test on the Lupin Diagnostics website.
- Choose your city and preferred centre location.
- Visit the centre at your scheduled time to submit your FFPE tissue block or arrange tissue submission as directed.
- Receive your report via email or WhatsApp within 3 days of sample processing.
Frequently Asked Questions
The TAG72 test helps pathologists identify adenocarcinomas (gland-forming cancers) and classify tumours by their origin. It is particularly useful for distinguishing lung adenocarcinoma from mesothelioma. The result is always interpreted alongside other clinical and pathological findings.
No. The TAG72 test requires a tissue sample from a biopsy procedure, which must be performed at a healthcare centre. Home collection is not available for this type of test. You can submit an existing FFPE paraffin block at a Lupin Diagnostics centre.
At Lupin Diagnostics, the report is typically ready within 3 days of the laboratory receiving the tissue block. Turnaround may vary if additional markers or repeat staining is needed.
A positive result means TAG-72 protein was detected in the tissue, which suggests the presence of an adenocarcinoma or a related epithelial cancer. It does not, on its own, confirm a final diagnosis. Your pathologist and oncologist will interpret the result in the context of all available information.
Most normal adult tissues do not show TAG-72 reactivity. Weak staining may occasionally appear in secretory endometrium and in a small number of benign breast or colon lesions. This is why results are always reviewed by a qualified pathologist with full clinical details.
No fasting is needed, as this is a tissue-based test. If you already have an FFPE block from a previous biopsy, it can be submitted directly. If a new biopsy is required, your doctor will provide specific preparation instructions for that procedure. Bringing your clinical history and prior reports is essential.
The TAG72 IHC test is performed on tumour tissue to classify cancer type or origin. The CA 72-4 blood test measures the same protein in the bloodstream and is sometimes used to monitor treatment response in certain gastrointestinal cancers. The two tests serve different purposes and are not interchangeable.
IHC Marker-TAG72 Test
