Tumor markers are substances that are present in, or produced by, tumor cells during tumor proliferation, or can be produced by the body in response to tumor stimulation. Doctors can find these substances by testing the patient’s blood, urine, and other body fluids.
There are no particularly reliable tumor markers for esophageal cancer, but a combination of two or more markers can be meaningful for diagnosis or screening.
In clinical practice, markers that physicians may choose include:
- Carcinoembryonic antigen (CEA)
- Glycoprotein antigen CA72-4
- Glycan antigen CA19-9
- Squamous cell carcinoma-associated antigen (SCC)
- Cytokeratin 21-1 (Cyfra21-1)
There are two broad conditions that require tumor markers:
- For patients with suspected or post-treatment disease, markers can be used as an adjunct to help diagnose or assess prognosis;
- For the physical examination population, markers are used as a screening tool and also serve to aid in the screening and early detection of esophageal cancer.
Why did my doctor recommend a tumor marker when I suspect esophageal cancer?
For suspected patients, tumor markers are a must. There are two specific reasons for this:
1. as an adjunctive diagnostic tool in high-risk groups
Tumors can be detected by tumor markers when they grow to 2 to 3 mm. It is an important clue to detect asymptomatic esophageal cancer and can be used as an adjunctive diagnostic tool.
In the diagnosis of esophageal cancer, the sensitivity of testing for one tumor marker alone is relatively low. For example, the sensitivities of Cyfra21-1, CA72-4, CEA, and CA19-9 were 49.16%, 30.89%, 28%, and 18%, respectively.
Why are the sensitivities of single tumor markers so low? There are roughly 3 reasons: 1. one tumor can produce multiple tumor markers; 2. different tumors or different tissue types of the same tumor can have the same tumor markers; and 3. the quality and quantity of tumor markers are highly variable from patient to patient.
So, instead of testing a single marker, the clinical practice is usually a “combination”. The combination of two or more tumor markers will result in more reliable results and significantly higher sensitivity. For example, a combination of Cyfra21-1 and CA72-4 has a positive detection rate of 65.00%, and CEA combined with CA19-9 can increase the sensitivity to 42%.
2.
2. Can be used for diagnosis, periodic review or efficacy evaluation, and prognosis assessment in patients with confirmed disease
- Staging and determination of benignity and malignancy
In patients with diagnosed tumors, tumor markers can help distinguish the benignity and type of tumor.
- Efficacy assessment of tumors
Tumor markers help to clarify whether surgery, radiation therapy, or drug therapy is effective. Often, tumor markers decline significantly after successful treatment.
- Tumor recurrence monitoring and prognosis determination
Tumor patients need to be reviewed regularly to monitor tumor marker levels dynamically to help determine if they have recurred. If the tumor marker level is higher than 25% of the first test at the time of review, it should be measured again in 2 to 4 weeks. If the level is elevated for 2 consecutive times, it may indicate recurrence or metastasis.
| Tumor marker review | |
|
Retest time |
Number of reviews |
|
First review |
|
|
Tested once every 3 months |
|
|
3 to 5 years |
Tested every six months |
|
5 to 7 years |
Tested once a year |
What does it mean when a tumor marker is found to be elevated during a physical exam?
Does an elevated corresponding tumor marker on a physical exam mean that you have esophageal cancer? No, it does not.
Tumor markers are only relatively specific or abnormal substances produced by tumors and have no effect on the development of tumors by themselves. The most important thing is that it is not a good idea to use it as a marker. Therefore, tumor markers are only an aid to diagnose or assess the efficacy of treatment. Imaging data and pathological diagnosis are the gold standard for diagnosis. There are also no therapeutic drugs or methods for tumor markers in clinical practice.
If you have an elevated tumor marker during a physical exam, your doctor will take a detailed history, including past medical history and current symptoms, to see if the disease is benign first. If esophageal cancer is suspected, you will be asked to undergo upper gastrointestinal imaging, gastroscopy, and other tests.
To learn more about diagnosing esophageal cancer, read the following articles: