Carcinoembryonic antigen CEA: why it increases

Scientific editor: M. Merkusheva, PSPbSMU named after. acad. Pavlova, medical practice. March, 2021.

Synonyms: carcinoembryonic antigen, CEA, carcinoembryonic antigen, Carcinoembryonic Antigen, CEA.

Cancer embryonic antigen (CEA) is a protein component of the blood, a tumor marker that is used in the diagnosis of benign and malignant processes in the gastrointestinal tract. A healthy body produces CEA in minimal quantities, but under the influence of unfavorable factors (smoking, poor diet, etc.) its level may begin to increase.

CEA analysis allows for the timely detection of malignant processes in the large intestine and other organs (rectum, stomach, lungs, ovaries, mammary glands).

General information

Cancer embryonal antigen was first identified in 1965 in a patient with colon cancer. This enzyme of protein origin begins to be produced in the fetus from the moment the gastrointestinal tract organs (esophagus, stomach, liver, pancreas, intestines) are formed. At this time, the concentration of the substance reaches its limit. After the birth of a child, a small amount of CEA remains in the blood plasma, which tends to decrease with age. The substance is found in residual quantities not only in the blood, but also in the tissues of the gastrointestinal tract and lungs, the epithelium of the mammary glands, on mucous surfaces, in the cerebrospinal and ascitic fluid. After birth, the gene that is responsible for the production of embryonic antigens should normally be deactivated.

An increase in CEA levels in adults is observed during a pathological (usually benign or malignant) process, inflammation, autoimmune diseases, as well as during pregnancy (increases by the 3rd trimester, but the values remain normal or long-term smoking.
Note: the habit of smoking leads to an increase in CEA in the blood, which indicates an increased risk of cancer. In a healthy person, the norm of CEA in the blood is up to 2.5 ng/ml of blood, while in a smoker it can reach 5 ng/ml or more. Complete
smoking cessation in just 3 months leads to a significant improvement in pulmonary function parameters and a decrease in serum CEA.

CEA analysis allows early diagnosis of malignant processes in the following organs:

primarily cancer of the colon and rectum;
bronchi and lungs;
gastrointestinal organs (including the pancreas);
pelvic organs (uterus and appendages, prostate gland);
mammary glands;
liver metastases;
metastases to bone tissue.

Progress of the study

The analysis is carried out in laboratory conditions using an enzyme immunoassay. To conduct the study, it is necessary to take biomaterial, namely venous blood. It is placed in vacuum tubes labeled with patient information. Before testing, blood is stored in thermally stable conditions.

Determining the concentration of carcinoembryonic antigen is a lengthy process, since the resulting biomaterial goes through several stages of preparation. Among them are centrifugation with further application of plasma to diagnostic media.

To obtain a reliable result and eliminate errors during laboratory diagnostics, it is necessary to follow the preparation rules. If these recommendations are not followed, there is a high likelihood that the indicators will be inaccurate.

In addition, before conducting the study, the laboratory doctor must be provided with information about the possible use of medications, smoking history, and the presence of pregnancy.

Indications

An oncologist, a surgeon, a functional diagnostician and a competent therapist can give a referral for analysis and give an interpretation of the results of the study for the CEA tumor marker.

First of all, a specialist prescribes a test for CEA in the blood if there are alarming symptoms indicating the development of a benign or malignant process:

sensation of a foreign body in the body, visual identification of a tumor and/or palpation;
constipation, feeling of incomplete bowel movement, rectal bleeding;
severe chest cough for a long time, shortness of breath;
causeless increase in body temperature, fever;
sweating during night rest;
indigestion, lack of appetite;
chronic weakness and lethargy, decreased strength, muscle tone;
a sharp decrease in body weight without objective reasons;
rapid loss of fluid from the body;
hyperthyroidism (hypersecretion of thyroid hormones);
an increase in the number of moles on the body over a short period of time;
bleeding of unknown origin;
long-term healing of wounds on the body;
aching and nagging pain without an established cause.

In addition to the above symptoms, a CEA test is prescribed in the following cases:

determination of the type, location, stage of the malignant process, the presence of metastases;
choosing a conservative cancer therapy regimen and assessing its effectiveness;
determining the effectiveness of surgical treatment of the tumor (CEA should return to normal 2 months after surgery). Moreover, CEA levels are often high at the time of relapse, even if they were normal before the initial tumor was removed, so CEA testing should be performed regularly long after surgery, regardless of whether high levels were present at the time of initial diagnosis.
standard analysis for suspected benign or malignant processes in the gastrointestinal tract, especially the rectum or colon;
if there is a suspicion of tumors of the breast, lungs, ovaries, tumor metastasis to the liver and bones;
planned analysis for patients over time after completion of oncology treatment.

An annual study of the concentration of CEA in the blood is carried out for patients who are at risk for the following factors:

heredity (first-degree relatives had cancer of internal organs);
work in hazardous industries (risk of poisoning by toxins, radioactive components, radiation exposure);
living in an unfavorable region with a high level of radioactivity, close to industrial enterprises;
abuse of solarium (artificial tanning increases the likelihood of benign and malignant processes), sunbathing;
elderly patients over 60 years of age with a burdened medical history (alcohol or cigarette abuse, presence of second- and third-degree relatives with cancer of internal organs).

PSA tests

Antigen (tumor marker) that indicates prostate cancer - PSA (prostate specific antigen). Testing for this substance allows you to detect cancer at an early stage and determine the extent of its prevalence.

Why is a PSA test performed?

An analysis for the level of total PSA in the body can be prescribed to men in the following cases.

Early diagnosis of prostate cancer, confirmation of the presumptive diagnosis after other types of examination (for example, digital rectal examination, ultrasound).
Differential diagnosis of prostate cancer, detection of benign hyperplasia of this gland.
Monitoring the effectiveness of radical prostatectomy for patients with prostate cancer. In such a situation, doctors recommend examinations every three months.
Evaluation of the effectiveness of conservative therapy, which is carried out for the purpose of non-operative treatment of prostate cancer.
Examination of patients with prostate cancer to detect relapses of the disease (preclinical).
Examination of patients with benign hyperplasia, which makes it possible to verify the effectiveness of the treatment and to detect a possible process of malignancy.

Doctors strongly recommend that all males over the age of 40 undergo an annual PSA antigen test. This will allow us to detect the risk of developing the disease at an early stage and begin treatment. The price of a blood test for this antigen is not so high as to risk your own health and even life by refusing diagnostics.

How the research is carried out

Checking the level of PSA concentration for compliance with the norm in the male body is carried out in blood, which is taken from the patient’s vein. Blood is drawn from a man before 11 a.m., which reduces the risk of destruction of the integrity of blood cells. At least 2 ml of biological material is taken. As a rule, total PSA is determined, but if clarification of the presumptive diagnosis is required, the level of free prostate-specific antigen can also be checked.

How to Prepare for a PSA Test

In order for this study to show correct results, the patient must strictly follow the basic rules of preparation for it. Preparation for a test for the level of male PSA markers in the blood is based on the following principles.

Two days before the test, the man must adhere to a strict diet. Fatty, spicy and fried foods are completely excluded from the menu, and alcohol consumption is not allowed.
Blood for analysis for the PSA tumor marker is taken exclusively on an empty stomach, the time of the last meal is 12 hours before the test. During this period, a man can only drink clean water without gas.
Immediately before submitting biological material for research, you need to abstain from cigarettes - at least a couple of hours before the tests.
A few days before testing the PSA level in the body, you need to start abstaining from sports activities.
Sexual contacts are completely excluded approximately 5-7 days before the test.
It is advisable to donate blood for testing before undergoing a urological examination. Or wait about 10 days after it is carried out.
If the patient has undergone a prostate biopsy, it is necessary to wait at least a month.
The PSA test, like all other types of tests for tumor markers in the blood, is recommended to be taken in a calm state. Immediately before the analysis, the man should rest and relax.

What should you tell your doctor about?

The patient should inform the doctor about factors that may negatively affect the reliability of the results, since even tests for tumor markers can be erroneous.

Be sure to report all medications you are taking.
The patient should inform the doctor about the presence of benign prostatic hyperplasia, prostatitis, and recent medical procedures related to the prostate gland.

REA is normal

Important! Standards may vary depending on the reagents and equipment used in each particular laboratory. That is why, when interpreting the results, it is necessary to use the standards adopted in the laboratory where the analysis was carried out. You also need to pay attention to the units of measurement.

In babies in the womb, the indicator is overestimated and may remain so for some time after birth. As a rule, the analysis is carried out on adults, where reference values will differ for people with and without nicotine addiction.

for non-smokers: 0 - 3.8 ng/ml;
for smokers: 0 - 5.5 ng/ml.

Important! The interpretation of the results is always carried out comprehensively. It is impossible to make an accurate diagnosis based on only one analysis.

Increasing values

If the permissible values (6.5 – 10 ng/ml) are exceeded, the development of a benign process in internal organs is suspected, but the initial stage of cancer cannot be ruled out. If CEA has reached 10 ng/ml and continues to rise, then additional studies are used to diagnose oncological processes in the body. As a rule, in cancerous tumors, the cancer embryonic antigen can increase several times, and in the presence of metastasis, the rate exceeds the norm by several tens of times.

Increase to 10 ng/ml

An increase to 10 ng/ml may indicate the following pathological processes:

neoplasms of internal organs (neurinomas, lipomas, polyps, fibromas, cysts, etc.);
ulcerative processes in the mucous membrane of the stomach and colon;
benign liver tumors (hepatocellular adenoma, hemangioma) and diseases (hepatitis, cirrhosis, acute alcohol or chemical intoxication, nodular hyperplasia);
respiratory diseases (pneumonia, bronchitis and others);
Crohn's disease (granulomatous inflammation of the gastrointestinal tract);
emphysema (pathological expansion of the alveoli of the lungs);
tuberculosis;
inflammation of the gastrointestinal tract, including the pancreas (pancreatitis);
renal failure;
cystic fibrosis (severe damage to the exocrine glands).
autoimmune diseases;
smoking

CEA is greatly increased

When the CEA concentration increases to more than 10 ng/ml, the following malignant processes are suspected:

cancer of the rectum, colon or colon (CEA is more enlarged with right-sided organ damage);
cancer of the respiratory system (lungs, bronchi, pleura);
stomach cancer (additionally, tests for CA 19-9 and CA 72-4 are prescribed);
cancer of the female genital organs (uterus and cervix, ovaries), prostate gland in men;
oncology of other internal organs (less commonly): mammary glands, esophagus, thyroid gland (medullary carcinoma), bladder, liver, etc.;
metastases in bone tissue, liver.

Table: sensitivity of CEA to diseases:

An increase in CEA concentration of more than 20 ng/ml before treatment indicates tumor metastasis.

Prevention and treatment of cancer

In order to reduce the risk of developing cancer, as well as reduce elevated CEA levels, it is necessary to lead a healthy lifestyle, walk in the fresh air more often, avoid stressful situations and undergo regular medical examinations. In addition, you should adhere to a special diet that includes green plants, fruits and vegetables with anti-cancer properties (citrus fruits, pineapples, peaches, tomatoes, zucchini, carrots, garlic), rosehip decoction and green tea.

The following methods are used to treat cancer:

Surgical intervention is suitable only for the initial stages of cancer, when metastases have not spread to other organs and tissues; it removes the affected tissues and areas entirely; there are no serious side effects.
Chemotherapy - through special chemicals, the process of metastasis is slowed down or completely stopped, but a negative effect also occurs on healthy cells.
Radiation therapy – through irradiation of diseased tissue.
Hormone therapy is an additional method for the treatment of cancer of the reproductive system.

Cancer is curable if it is detected early and appropriate therapy is started.
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