Tumour Markers Test – What Your Results Mean

Key Takeaways ● A tumour markers test measures substances linked to some cancers. Common examples are CEA, CA 125, AFP and CA 19-9. ● Tumour markers are mainly used to monitor treatment and check for recurrence. They are rarely used on their own to diagnose cancer. ● A high result does not always mean cancer. Infections, liver disease, pancreatitis, gallstones, endometriosis, pregnancy and smoking can raise some markers. ● A normal result does not rule out cancer. Some cancers do not produce detectable markers, especially in early stages. ● The trend matters more than one number. Doctors compare results over time, ideally from the same laboratory. ● Most tumour markers are not screening tests. They are generally not recommended for people without symptoms.

A tumour markers test, also spelled tumor marker test, measures substances in the blood that can be produced by cancer cells or by the body in response to cancer. The most commonly ordered tumour markers include the CEA test, CA 125 test, AFP test and CA 19-9. Doctors read these results alongside scans, biopsy findings and symptoms, never on their own.

A lab report with a value marked “high” can be worrying. Yet many of the same substances also rise in non-cancerous conditions, and normal ranges differ between laboratories. Understanding what each marker measures can make the report easier to discuss with your doctor.

What Are Tumour Markers?

Tumour markers are usually proteins, hormones or other molecules found in blood, urine or tissue. Most of those discussed here are measured with a simple blood test (National Cancer Institute, 2023).

Doctors mainly use tumour markers to:

● Monitor how a cancer is responding to treatment

● Check for recurrence after treatment has finished

● Support a diagnosis, together with scans and biopsy

● Estimate how extensive a cancer may be at diagnosis

What tumour markers generally cannot do is screen healthy people for cancer, because most are not sensitive or specific enough (Sturgeon et al., 2008). A few exceptions exist for selected high-risk groups, such as AFP surveillance in some people with long-term hepatitis B or cirrhosis.

Common Tumour Markers and Their Normal Ranges

Reference ranges vary between laboratories and test methods. Always compare your result with the range printed on your own report.

Marker	Main cancers it is used for	Commonly used upper limit	Non-cancer causes of a raised level
CEA	Colorectal; also lung, breast, stomach, pancreas	About 3 ng/mL (non-smokers) to 5 ng/mL (smokers)	Smoking, inflammatory bowel disease, liver disease, pancreatitis
CA 125	Ovarian; sometimes endometrial	35 U/mL	Menstruation, pregnancy, endometriosis, fibroids, pelvic infection, liver disease
AFP	Liver (hepatocellular); germ cell tumours	About 10 ng/mL in non-pregnant adults	Pregnancy, hepatitis, cirrhosis
CA 19-9	Pancreatic, bile duct, gallbladder; sometimes stomach and colon	37 U/mL	Gallstones, blocked bile duct, pancreatitis, cirrhosis

[NOT TO PUBLISH: clinical team to confirm the indicative ranges above]

CEA Test (Carcinoembryonic Antigen)

The CEA test measures a protein that is normally present in very small amounts in adults. It is most often used in colon cancer to monitor treatment and to check for recurrence after surgery (Locker et al., 2006). It may also be raised in lung cancer, breast cancer, stomach cancer and pancreatic cancer.

CEA normal range

Many laboratories use an upper limit of about 3 ng/mL for non-smokers and about 5 ng/mL for smokers. Smoking can raise CEA on its own, which is one more reason to quit tobacco.

What a raised CEA can mean

A mildly raised CEA can occur with smoking, inflammatory bowel disease, peptic ulcer, liver disease, pancreatitis or lung infection. In a person treated for colorectal cancer, a steadily rising CEA over several tests is a signal for the doctor to investigate further, usually with imaging. A normal CEA does not rule out cancer, because some cancers never produce it.

Expert Insight “A single tumour marker value rarely tells the whole story. What matters is how the level changes over time and how it fits with scans, symptoms and the overall treatment plan.” Dr. Tarang KrishnaMDManaging Director, Cancer Healer Center

CA 125 Test

CA 125 is a protein found on the surface of many cells, especially ovarian cancer cells. The CA 125 test is used mainly to monitor ovarian cancer during and after treatment, and to help assess a pelvic mass together with ultrasound.

CA 125 normal range

Most laboratories consider a CA 125 level below 35 U/mL to be within the normal range. Levels can be naturally higher during menstruation and pregnancy.

What a raised CA 125 can mean

CA 125 can rise in many benign conditions, including endometriosis, uterine fibroids, pelvic inflammatory disease, ovarian cysts, liver cirrhosis and fluid in the abdomen. It can also rise in cancers of the uterus, cervix, pancreas, lung and breast.

Is CA 125 a Screening Test? CA 125 is not raised in every woman with early ovarian cancer and can be raised without cancer. For this reason it is not recommended as a screening test on its own for women at average risk.

AFP Test (Alpha-Fetoprotein)

AFP is made by the developing baby during pregnancy and normally falls to low levels after birth. In adults, the AFP test is used to help diagnose and monitor liver cancer (hepatocellular carcinoma) and certain germ cell tumours of the testis or ovary.

In non-pregnant adults, AFP is usually below about 10 ng/mL, although laboratories differ. AFP is also raised during pregnancy and in hepatitis and cirrhosis. People with chronic hepatitis B or cirrhosis may be advised regular AFP tests with ultrasound as part of liver surveillance.

CA 19-9 Test

CA 19-9 is used mainly in pancreatic cancer and cancers of the bile duct and gallbladder to track response to treatment. The commonly used upper limit is 37 U/mL (Ballehaninna and Chamberlain, 2012).

CA 19-9 can rise sharply when the bile duct is blocked for any reason, including gallstones, so results during jaundice must be interpreted carefully. A small proportion of people cannot produce CA 19-9 because of their blood group antigens, so their level stays low even if cancer is present.

Other Tumour Markers Your Doctor May Order

Marker	Used mainly in
PSA (prostate-specific antigen)	Prostate cancer
CA 15-3 / CA 27-29	Monitoring advanced breast cancer
Beta-hCG	Germ cell tumours and gestational trophoblastic disease
Thyroglobulin, calcitonin	Follow-up of thyroid cancer
Chromogranin A	Neuroendocrine tumours
Serum free light chains, beta-2 microglobulin	Multiple myeloma
LDH	Lymphoma, germ cell tumours and others

How to Read Your Tumour Marker Results

1. Look at the trend, not one number. Doctors compare a series of results over weeks or months.

2. Use the same laboratory when possible. Different machines and methods give different numbers.

3. Know your baseline. The level before treatment is the reference point for later results.

4. Expect some fluctuation. Levels can briefly rise soon after chemotherapy starts, and the doctor interprets this in context.

5. Read it with scans and symptoms. Treatment decisions are rarely based on a marker alone.

Understanding where you are in treatment also helps. See how cancer type, stage and overall health shape care and why keeping a complete cancer treatment history, including past marker reports, matters.

Note A tumour marker result alone cannot confirm cancer, rule it out or tell you its stage.

Should You Get a Tumour Marker Test Without Symptoms?

For most healthy people, no. A tumour marker panel done without a clear reason can produce a false alarm, leading to anxiety and repeat tests. It can also falsely reassure, because a normal value does not exclude cancer. People worried about their cancer risk should discuss appropriate screening for their age, sex and family history with their doctor.

When to Discuss Your Tumour Marker Report With a Doctor

Tumour markers are useful tools, especially for tracking treatment and follow-up in people already diagnosed with cancer. But a raised CEA, CA 125, AFP or CA 19-9 is not a diagnosis, and a normal one is not a guarantee. Read the number against your laboratory’s range, look at the trend and talk it through with your oncologist before drawing conclusions.

At Cancer Healer Center, the team led by Dr. Tarang Krishna reviews each patient’s diagnosis, treatment history and reports, and discusses supportive-care options. Cancer Healer Therapy (CAM) is an individualised, immune-focused supportive approach used alongside oncologist-prescribed treatment. It does not replace chemotherapy, radiation, surgery, immunotherapy or targeted therapy, and supportive care cannot guarantee changes in tumour marker levels, remission or cure.

References

Ballehaninna, U.K. and Chamberlain, R.S. (2012) ‘The clinical utility of serum CA 19-9 in the diagnosis, prognosis and management of pancreatic adenocarcinoma: an evidence based appraisal’, Journal of Gastrointestinal Oncology, 3(2), pp. 105–119. doi:10.3978/j.issn.2078-6891.2011.021.

Locker, G.Y. et al. (2006) ‘ASCO 2006 update of recommendations for the use of tumor markers in gastrointestinal cancer’, Journal of Clinical Oncology, 24(33), pp. 5313–5327. doi:10.1200/JCO.2006.08.2644.

National Cancer Institute (2023) Tumor Markers. Bethesda, MD: National Cancer Institute.

National Cancer Institute (2023) Tumor Markers in Common Use. Bethesda, MD: National Cancer Institute.

Sturgeon, C.M. et al. (2008) ‘National Academy of Clinical Biochemistry laboratory medicine practice guidelines for use of tumor markers in testicular, prostate, colorectal, breast, and ovarian cancers’, Clinical Chemistry, 54(12), pp. e11–e79. doi:10.1373/clinchem.2008.105601.