CA 19-9 Test
About CA 19-9 Test
| Field | Value |
|---|---|
| Also Known As | Cancer Antigen 19-9, CA 19-9, Carbohydrate Antigen 19-9, CA 19-9 Assay, CA 19-9 Radioimmunoassay, Pancreatic Cancer Marker Test, Sialyl-Lewis A Antigen |
| Sample Type | Venous blood (serum) |
| Fasting Required | No fasting required |
| Report Time | Within 24 to 48 hours |
| Recommended For | Adults of all genders; particularly those with suspected or diagnosed pancreatic, biliary, or gastrointestinal cancers |
| Price | Starting at ₹1,100 |
What Is a CA 19-9 Test?
The CA 19-9 test is a blood test that measures a protein called Carbohydrate Antigen 19-9 in the blood. This protein is known as a tumour marker a substance produced by cancer cells or by normal cells in response to cancer. Doctors typically order this test to monitor known cancers of the pancreas, bile ducts, and digestive tract, or to investigate symptoms that may suggest such conditions.
The test is also called the Cancer Antigen 19-9 test or CA 19-9 assay.
What Does a CA 19-9 Test Measure?
The CA 19-9 blood test measures a single tumour marker in the blood. Below is a summary of what it assesses and why it matters.
| Parameter | What It Measures | Why It Matters |
|---|---|---|
| CA 19-9 | Level of Carbohydrate Antigen 19-9 in the serum | Elevated levels may indicate certain cancers or other conditions affecting the pancreas, liver, or bile ducts |
Why Is a CA 19-9 Test Done?
A doctor may order a CA 19-9 test for several reasons, from investigating new symptoms to tracking a known diagnosis. The sections below explain when this test is commonly used.
Common Symptoms That May Require This Test
Your doctor may recommend this test if you are experiencing any of the following:
- Abdominal pain, particularly in the upper abdomen
- Unexplained weight loss
- Jaundice (yellowing of the skin or eyes)
- Loss of appetite
- Persistent nausea
- Unexplained fatigue
- Back pain without a clear cause
Conditions This Test Can Help Detect
The CA 19-9 assay can help doctors assess a range of conditions, including:
- Pancreatic cancer (the most common condition this marker is associated with)
- Cancers of the bile ducts, gallbladder, stomach, colon, and rectum
- Colorectal cancer and lung cancer
- Benign conditions such as gallstones blocking the bile ducts, pancreatitis, cholangitis, cirrhosis, and liver disease
- Cystic fibrosis
CA 19-9 Test for Chronic Disease Monitoring
The CA 19-9 blood test plays an important role in monitoring patients undergoing treatment for pancreatic and other digestive tract cancers. Levels are typically measured before treatment begins and then tracked every one to three months during chemotherapy, radiation therapy, or other targeted treatments. This serial monitoring helps doctors assess how well the treatment is working and whether the cancer is responding.
How to Prepare and What to Expect
Preparation for the CA 19-9 test is straightforward, and the procedure itself is quick and simple. The information below covers everything you need to know before your appointment.
Do You Need to Fast?
No, fasting is not required before a CA 19-9 blood test. You can eat and drink normally before the test. However, always check with your doctor before the appointment, as individual circumstances may vary.
Practical Tips Before Your Test
Keep these points in mind before going for your test:
- Tell your doctor about all medications and supplements you are currently taking
- If you take biotin (also called Vitamin B7, Vitamin H, or Coenzyme R), stop taking it at least 72 hours before your test, as it can interfere with results; if you are on a high-dose biotin therapy above 5 mg per day, stop at least 8 hours before sample collection
- Wear a short-sleeved or loose-sleeved top to allow easy access to your arm
- Stay well hydrated before the test, as this makes it easier to locate a vein
Step-by-Step Procedure
Here is what to expect during sample collection:
- A trained phlebotomist or nurse will clean a small area on your arm with an antiseptic swab.
- A small needle will be inserted into a vein, usually on the inside of your elbow.
- A small amount of blood is drawn into a test tube or collection vial.
- The needle is removed and a small bandage or cotton swab is placed on the site.
- The entire process typically takes less than five minutes and causes minimal discomfort.
- The blood sample is labelled and dispatched to the laboratory, where it is analysed using immunoassay techniques.
Factors That Can Affect Accuracy
Certain factors may influence the accuracy of your CA 19-9 assay results:
- High-dose biotin supplementation can interfere with the test and alter readings
- The presence of jaundice or bile duct obstruction may cause levels to appear falsely elevated
- Lewis blood group status: roughly 5 to 10% of people cannot produce the CA 19-9 antigen, meaning their results will always appear low or undetectable regardless of health status
- Using different laboratories for repeat testing, as different labs may use different measurement methods
- Certain medications and supplements, if not disclosed to your doctor
Understanding Your CA 19-9 Test Results
Your results should always be reviewed by a qualified doctor who can consider them alongside your symptoms, medical history, and any other investigations. The table below shows the general reference range used for this test.
| Parameter | Normal Range | Unit | What It May Mean If Outside Range |
|---|---|---|---|
| CA 19-9 | 0 to 37 | U/mL | Values above 37 U/mL may suggest cancer or certain non-cancerous conditions; values below this range are considered normal |
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 health conditions can affect how your Carbohydrate Antigen 19-9 results are read:
- Jaundice and cholestasis (bile blockage) caused by liver disease, cirrhosis, or pancreatitis can cause CA 19-9 levels to appear falsely high, which may complicate interpretation.
- Individuals with a Lewis-negative blood phenotype (approximately 5 to 10% of the population) may show undetectable or very low CA 19-9 levels even when cancer is present, which can result in a false negative reading.
- Hypothyroidism may cause a slight elevation in CA 19-9 levels; levels may return to normal once thyroid function improves.
- High-dose biotin supplementation can interfere with the assay, causing results to shift on certain testing platforms.
How to Maintain Healthy Levels
While the CA 19-9 test is not a general wellness marker, the following lifestyle habits support overall pancreatic and liver health:
- Follow a balanced diet rich in vegetables, whole grains, and lean proteins, and maintain a healthy body weight
- Limit or avoid alcohol, as excessive consumption can harm the liver and pancreas over time
- If you have conditions such as chronic pancreatitis or diabetes, work closely with your doctor to keep them well managed
Lupin Diagnostics CA 19-9 Test Price and Home Collection
The CA 19-9 test is available at Lupin Diagnostics with home collection offered across cities. Prices start from ₹1,100, and the indicative city-wise pricing is shown below.
| City | Approximate Price (₹) |
|---|---|
| Hyderabad | ₹1,100 |
| Mumbai | ₹1,100 |
| Bangalore | ₹1,100 |
| Chennai | ₹1,100 |
| Kolkata | ₹1,100 |
| Pune | ₹1,100 |
| Indore | ₹1,100 |
| Bhubaneshwar | ₹1,450 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
1. Select the test on the Lupin Diagnostics website
2. Choose your city and preferred time slot
3. Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre
4. Receive your report via email or WhatsApp within the stipulated turnaround time
Home Collection
Lupin Diagnostics offers home sample collection for the CA 19-9 blood test across multiple cities, making it easy to get tested from the comfort of your home. All samples are processed in NABL-accredited laboratories by experienced professionals. Your digital report is delivered via email or WhatsApp, typically within 24 to 48 hours.
Frequently Asked Questions
The CA 19-9 test is primarily used to help distinguish pancreatic cancer from other conditions, and to monitor how well cancer treatment is working. It may also be used to check whether a cancer has returned after treatment. It is not used as a standalone diagnostic tool.
No. The CA 19-9 assay cannot be used alone to screen for or diagnose pancreatic cancer. Elevated levels can have several causes, both cancerous and non-cancerous. Doctors use it alongside imaging tests and other investigations to build a complete picture.
No fasting is needed before a CA 19-9 blood test. You can eat and drink as normal. However, you should inform your doctor about any supplements or medications you are taking, particularly biotin.
A raised CA 19-9 level may indicate certain cancers, such as pancreatic, colorectal, or gallbladder cancer, but it can also be elevated in non-cancerous conditions such as pancreatitis or liver disease. A high result always requires further investigation. Your doctor will advise on the next steps.
Some people cannot produce the CA 19-9 antigen due to their Lewis blood group type. This accounts for approximately 5 to 10% of the population. In these individuals, CA 19-9 levels may remain low or undetectable even when cancer is present, which is why the test is always used alongside other diagnostic tools.
The frequency depends on the doctor's assessment. During active treatment, the test is often repeated every one to three months. If the cancer appears to be progressing, testing may be done more frequently, such as after each treatment cycle.
Biotin supplements do not affect the CA 19-9 test price, but they can significantly affect your results. High-dose biotin can interfere with the laboratory assay and cause inaccurate readings. Stop taking biotin at least 72 hours before your test and inform your doctor if you use any biotin-containing products.
CA 19-9 Test
