Blood test for AFP (alpha-fetoprotein): what the study shows, the norm in women and men, interpretation of the results

What is AFP - a tumor marker?

Tumor markers are unique protein cells that are the body’s response to the presence and growth of cancer cells in the body, or the malignant tumor itself produces this type of molecule. To date, there are more than 200 types of tumor markers. The number of tumor markers can be checked by taking a blood test.

In addition to detecting cancer cells, tumor markers make it possible to monitor the dynamics after treatment of cancer and prevent their relapse.

In medicine, tumor markers are divided into types: first and second. The first type of tumor markers includes those proteins that are produced in the blood directly by the malignant tumor itself. The second type of tumor markers is produced by ordinary healthy cells, as a response of the immune system to the presence of nonspecific cells in the body. Since tumor markers of the first type are more informative in making a diagnosis, their concentration in the blood is first checked. Afterwards, tumor markers of the second type are examined.

The tumor marker AFP (alpha-fetoprotein, α-fetoprotein) is a marker of the first type. Histologically, it is a two-component protein (glycoprotein). It is mainly produced in the gall bladder, liver, and intestines of the embryo during the period of ontogenesis (intrauterine development of the fetus). In non-pregnant women, as well as men, the norm of alpha-fetoprotein does not exceed 15 ng/ml and is synthesized in the liver.

What else could AFP mean?

Let's look at what AFP means in a blood test in men.

A mild increase in alpha-fetoprotein levels in adults, as a rule, indicates abnormalities in the liver; when significantly exceeding the norm, the development of malignant tumors is indicated.

The degree of increase in AFP is not influenced by indicators such as the stage of the tumor, its size or growth rate; more precisely, tumors of an aggressive nature are accompanied by a less noticeable increase in the levels of this protein, which does not apply to more differentiated carcinomas. However, there are cases where in approximately half of patients with liver cancer, the AFP level is elevated already 1-3 months before the onset of the first symptoms of the disease. We learned what the ACE blood test means. How to prepare for this study?

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The role of this protein in the proper formation of the fetus is invaluable. Has such functions as:

• Transport of cells. In an adult, this task is performed by albumin;
• Controls estrogen production during pregnancy;
• Protects the fetus from the negative effects of the immune system. During pregnancy, the immune system perceives the embryo as a foreign body and attacks it with the goal of rejection. In this case, the AFP protein serves as a kind of barrier to the fetus.

It should be noted that the level of this protein must strictly correspond to the duration of pregnancy.
Typically, at 13 weeks the highest level of AFP in the fetus is observed, when, like a pregnant woman, a high concentration in the blood is detected at 30-32 weeks. And the values ​​of this protein begin to increase from the 10th week from the day of conception. By the end of the child's first year of life, the level of α-fetoprotein is compared with the level of this protein in the blood of an adult. In gynecology, together with genetics, a deviation from the norm in the level of AFP, in combination with other types of hormones, may indicate the presence of abnormalities in the development of the fetus, chromosomal mutations.

In oncology, in non-pregnant women and men, a high level of AFP may indicate cancer of the liver, uterus, mammary glands, and lungs. The presence of this marker in the blood indicates that the body is trying to fight cancer cells. In addition to cancer, changes in the level of α-fetoprotein may indicate the presence of liver cirrhosis, as well as hepatitis.

An increase or decrease in the concentration of the tumor marker AFP in the blood cannot absolutely indicate the presence of cancerous tumors, and even more so it is impossible to judge based on these indications the size and level of spread of the pathology. To establish an accurate diagnosis, it is necessary to carry out more extensive diagnostic measures.

Indications for analysis

To determine the level of AFP in blood serum, the following basic indications are necessary:

• Presence of suspicion of prenatal pathology, i.e. the presence of chromosomal diseases, disorders of brain development, defects of other organs.

• When hepatocellular cancer and diagnosis of metastases of other types of liver cancer are excluded.

• When genital tumors are excluded.

• If necessary, monitor the effectiveness of antitumor therapy from its beginning to its end.

If there is a high growth rate of cancer development in liver disease, an analysis is performed to determine the level of alpha-fetoprotein, which makes it possible to identify neoplasms at an early stage of development. What does AFP mean in a blood test for women?

An AFP test during pregnancy is a screening test that is carried out during the period when its level increases in the expectant mother - between 15 and 21 weeks.

A mandatory determination of AFP in a pregnant woman is required in the following cases:

• consanguineous marriage;
• presence of genetic predisposition;
• existing children in the family with congenital anomalies;
• first birth at the age of over 35 years;
• taking toxic drugs or x-ray examination of the expectant mother in the early stages of pregnancy.

Why is AFP level testing prescribed?

There are several reasons why it is necessary to check the amount of α-fetoprotein in the blood:

• Pregnant women at certain stages of pregnancy for timely detection of developmental anomalies in the fetus, the presence of chromosomal mutations;
• As an additional means of diagnosing cancer of the liver, pancreas, testicle, lungs, colon and other poorly differentiated types of cancer;
• It is possible to judge the presence of metastatic processes in the body;
• In addition to cancer, AFP may indicate hepatitis, hepatic cirrhosis, blockage of the bile ducts, cholelithiasis, liver damage due to alcohol addiction;
• The level of the tumor marker AFP in the blood can be a kind of indicator after a course of treatment for cancer. Based on its content in the blood, one can observe the dynamics of the disease, as well as the success of the chosen treatment tactics. Also, a sudden increase in α-fetoprotein levels may indicate a relapse.

It should be noted that the concentration of this protein in cancer reaches more than 400 IU/ml. For non-oncological pathologies, these numbers are several times lower.

Even a high level of α-fetoprotein at 16 weeks of pregnancy may not necessarily indicate mutations in the child, and a low level may not indicate the presence of Down syndrome. But this fact cannot be ignored. Additional diagnostics are required.

Types of tests for tumor markers

Tumor markers are materials of protein origin that are produced in the human body due to an oncological predisposition. Tumor cells supply these proteins into the blood from the moment the tumors just begin to appear and develop, therefore, with the help of diagnosis, it is possible to identify the disease at the minimum stages of development.

Attention! Today, there are already over two hundred types of tumor markers. Some of them are quite specific, so by examining them, it is possible to identify the localization of the tumor.

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Not only cancer, but also a number of other ailments can affect the increase in test values. Everything, including AFP and hCG tumor markers, are biological components that are formed in the peripheral blood or other environment of the human body if the onset of cancer occurs. Their presence can be determined using special laboratory tests.

At the moment, many different markers have been discovered to identify cancer diseases. Each of them helps to detect cancer in the early stages. Analysis for the tumor marker AFP (interpretation: alpha-fetoprotein), the norm of which is also important, is no exception. An AFP tumor marker is a collection of macromolecules consisting of a protein mass that has a carbohydrate or lipid nearby.

Such substances are produced directly by cancer cells. Some molecules end up in the blood, where they can actually be tracked using laboratory tests.

There is a second type of tumor markers - biologically active substances produced by ordinary cells of a healthy person in acceptable quantities. If suddenly a malignant tumor grows in the body, such markers quickly react to the aggressiveness of the cancer. As a result, enzymes, hormonal substances or similar active materials are formed intensively and in large quantities in the diseased organ or even in other systems. These formations act as nonspecific tumor markers.

For a reliable result, the patient is always recommended to check tumor markers of the first type, because they clearly belong to a specific organ. After studying such proteins, the second type is examined, high levels of which may indicate cancer.

These substances are studied for various purposes:

• to identify new benign tumors that tend to become malignant;
• if there is a suspicion of cancer of any organs;
• to record the result after removal of malignant tumors during complex operations;
• to study the effectiveness of tumor treatments;
• to determine the initial stages of cancer;
• in order to predict the occurrence of oncological-type diseases.

A blood test for AFP is prescribed in the following cases:

• women during pregnancy;
• if there is a suspicion of pathology of intrauterine development;
• if you suspect oncological processes in the liver (hepatocellular cancer or hepatoblastoma);
• when monitoring the course of cancer;
• to clarify or make a diagnosis.

It is especially important to donate blood for AFP to pregnant women in the following cases:

• if infertility has been diagnosed in the past, there have been miscarriages or miscarriages;
• when fertilized by a blood relative;
• if the parents have a hereditary disease or genetic disorder;
• when a woman had an x-ray taken in the first three months of pregnancy;
• if the pregnant woman took medications with a toxic effect on the embryo;
• when a woman is over 35 years old and this is her first child;
• if the pregnant woman was influenced by negative environmental factors.

When diagnosing tumor processes, it is important to combine this study with the determination of other tumor markers.

Tumor marker PSA. This antigen in a man’s body indicates the development of prostate cancer - PSA is produced by its cells. Having received the results, it is possible to clarify the level of tumor prevalence. PSA tests are the earliest diagnosis of cancer. Therefore, doctors strongly recommend that all men over 40 years old undergo this test, even if at first glance everything is fine with the prostate.

Tumor marker AFP. This test diagnoses hepatocellular liver cancer at an early stage. The analysis monitors the patient's treatment. This analysis is also used in the field of gynecology: the level of tumor marker during pregnancy indicates the condition of the fetus.

Tumor marker CEA. This carcinoembryonic antigen is produced by cells of the digestive tract of the embryo and fetus. The substance is practically absent in the body of a healthy adult and pregnant women. Even a slow increase in its concentration allows doctors to determine the development of the oncological process.

Tumor marker CA 125. The presence of CA 125 in the body indicates ovarian cancer. A blood test for this antigen is necessary to monitor the effectiveness of therapy for various types of ovarian cancer (serous, endometrial, clear cell). The results of tumor marker concentration also make it possible to predict relapse and the formation of metastases within a few months.

Tumor marker CA 15-3. Testing for this tumor marker is an effective tool for diagnosing breast cancer. The analysis is also needed to check the effectiveness of treatment, to detect relapses, and to detect cancer metastases. The specificity of tumor marker readings makes it possible to accurately determine a malignant formation in the mammary glands.

Tumor marker CA 19-9. The study diagnoses a malignant neoplasm of the rectum and large intestine. A high level of tumor marker CA 19-9 detects metastases in the early stages and allows monitoring the development of the disease.

Tumor marker thyroglobulin (TG). Testing for thyroglobulin is a stage in the diagnosis of carcinoma (except for medullary cancer). The analysis is also important for early diagnosis of metastases and calculation of relapse in patients who have already undergone surgery. The value of this tumor marker also allows us to evaluate the effectiveness of treatment.

HCG analysis. The analysis is carried out to confirm conception, for early diagnosis of genetic abnormalities in the unborn child, detection of uterine cancer, and detection of ectopic pregnancy.

These tumor marker tests are considered the gold standard for cancer diagnosis worldwide.

Alpha-fetoprotein is looked for in tests when diagnosing secondary tumors in the liver.

Alpha-fetoprotein in the blood is looked for if the following diseases are suspected:

• Hepatocellular carcinoma. This is a rapidly developing malignant tumor of hepatocytes.
• Metastases to the liver. They enter the organ from cancerous growths in the stomach, intestines, kidneys, lungs, ovaries and other nearby structures.
• Testicular teratoblastoma. This is a malignant tumor of the male genital organs - the testicles.
• Ovarian teratoma. It is also a hormonally active neoplasm - a malignant adenoma.
• Hepatoblastoma. Liver tumors are more common in childhood.
• Down syndrome. A hereditary disease that is trisomy on chromosome 23.
• Edwards syndrome. It is a chromosomal abnormality that includes multiple malformations.
• Defect in the development of the neural tube or spinal column. In this case, the child is motionless from birth. The mortality rate in such children is also high.
• As part of prenatal screening in the second semester. In parallel with AFP, the level of choriogonadotropin and the hormone estradiol is measured.
• Down syndrome, Edwards syndrome, Shereshevsky-Turner syndrome.
• Abdominal wall defects. These include omphalocele (a hernia of the navel containing internal organs in a sac) and gastroschisis (eventeration of the intestines and stomach through an open opening).
• Anomalies of the urinary tract.
• Atresia of the esophagus and duodenum.

Knowing that the AFP tumor marker is a protein formation that helps to identify a dangerous pathology long before its clinical detection and the manifestation of any symptoms, in some cases you should undergo an examination.

The main indications for testing for cancer markers are:

• Genetic predisposition to cancer.
• Chronic liver diseases, hepatitis of all types, symptoms of cirrhosis.
• Suspicions of the presence of seals in the body.
• Precancerous conditions.
• Detected benign tumors with a high risk of degeneration into malignant ones.
• Monitoring the progress of treatment and after its completion in order to predict relapse.
• After removal of the pathological neoplasm.
• To predict the risk of metastasis of harmful pathologies.

It is also necessary for pregnant women to find out what the AFP tumor marker shows. In this case, the typical situation is when its level is high. This is due to the fact that the embryo is perceived by the body as a foreign body, and it tries to defend itself. But if Alpha protein is reduced, pathologies in the fetus should be suspected, for example, Down syndrome, trisomy and many others. At the same time, exceeding an already high level of protein also indicates problems with the development of the fetus, including the risk of intrauterine death.

To check whether the AFP tumor marker is increased, decreased or normal, it is necessary to donate venous blood in a specialized laboratory. The material for the study is a machine-separated serum into which antibodies are injected. The result of their interaction is the reaction, which is diagnosed by the doctor and a verdict is made: there is a pathology or there is only a risk.

The AFP tumor marker is deciphered by the same laboratory in which the analysis is carried out. The unit of measurement is the international unit per milliliter of blood (IU/ml).

In what cases does AFP increase?

A significant increase in the level of α-fetoprotein in the blood may indicate such pathologies as:

• Cancerous liver damage in 90% of cases;
• Presence of ovarian, breast, lung, intestinal cancer;
• The presence of metastatic processes in the body – in 10% of cases;
• The presence of pathological processes in the liver (cirrhosis, hepatitis, alcohol intoxication, liver injury);
• A pregnant woman has a cancer of the fetus, anomalies in the development of the internal organs of the fetus (urinary organs, esophagus, intestines, bones). The risk of miscarriage is also high, and pathological changes in the placenta are possible.

Normalization of indicator level

To normalize the AFP value, it is necessary to conduct additional studies to make an accurate diagnosis.

Treatment depends on the pathological condition and its severity. In addition, the individual characteristics of the patient’s body are also taken into account.

If the cause of the deviations is malignant neoplasms, then chemotherapy, radiation and surgery are prescribed.

When an increase in AFP is caused by benign processes, drug therapy is used.

If the indicator deviates in pregnant women, methods for normalizing this substance in the blood depend on the main reason for the increase or decrease.

Thus, AFP is an important indicator during pregnancy, so during routine screenings its level must be checked.

Any deviation may indicate genetic disorders and pathologies of intrauterine development. This protein is considered a tumor marker, so the study is prescribed even if oncological processes are suspected. Methods for normalizing an indicator depend on the main reason for the deviation.

The results for the tumor marker AFP, which shows too high or low a value, have their reasons. What diseases are signaled by changes in AF protein levels in the blood?

1. An indicator exceeding the age norm.

If the results are more than 10 IU/ml, then specialists prescribe various types of studies to the patient in order to establish the diagnosis as accurately as possible. It is believed that the excess of this protein means that the body is exposed to serious diseases, for example, breast, liver, lung cancer, the formation of malignant neoplasms in the testicles and ovaries.

1. For pregnant women, high results may indicate, first of all, the presence of several fetuses, and also:

• hepatic necrosis of a child;
• navel hernia;
• abnormalities of the urinary tract.

1. Too low test results for AF protein in expectant mothers indicate:

• abnormalities in fetal development;
• trisomy;
• cystic hickey;
• suspicious pregnancy.

There is also a temporary increase in AF protein. As mentioned above, levels of this substance may temporarily increase during pregnancy. At the fifteenth week, values ​​can range from 15-62 IU/ml, but by the twentieth week they can jump to 119 IU/ml. In addition, in ordinary people, a change in the level of A-fetoprotein can occur during exacerbations of cholelithiasis and cholecystitis, during transformation of the liver parenchyma, after various injuries or intoxications of the body.

Excessive accumulation of AFP can also occur in some diseases:

• liver cirrhosis;
• long-term and acute hepatitis;
• permanent kidney failure.

If, when analyzing the AFP tumor marker, the norm in women is underestimated (during pregnancy), this may indicate delayed development of the child and some ailments of the expectant mother. Thus, doctors often notice high concentrations in diabetes and obesity.

A too low AFP test result with poor results and other tests indicates a significant risk of giving birth to a baby with Down syndrome. But the most common explanation for a decrease in AFP is the low location of the placenta.

In order to determine the amount of A-fetoprotein tumor markers, a special AFP test is used, which doctors call the Tatarinov-Abelev reaction. This method allows you to find alpha-fetoproteins using precipitation in agar. Test results can take up to one week to process, which is why they are presented to patients after seven days.

In what cases does AFP decrease?

A decrease in the level of α-fetoprotein is also a reason to suspect the presence of a number of diseases:

• Mutations in chromosomes in the fetus (Down syndrome, Edwards syndrome, Patau syndrome);
• There is a possibility of fetal death during intrauterine development. In medicine, this phenomenon is called “frozen pregnancy”;
• If a woman has gained a lot of excess weight during pregnancy, then the AFP level may also decrease;
• Inhibition of fetal development due to the proliferation of chorionic villi.

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Rules for taking the analysis

The stage of preparation for passing the analysis is important for reliable results. The recommendations are:

1. The day before the procedure, it is better to completely give up alcohol, as well as fatty, fried, smoked foods;
2. It is better to take the test on an empty stomach, or at least not earlier than 4 hours after the last meal;
3. Refrain from physical and emotional stress an hour before the procedure;
4. You should not smoke half an hour before taking the test;
5. Experts recommend not taking B vitamins at least 8 hours before the procedure.

The cost of the analysis is usually insignificant and this type of laboratory examination can be carried out in any hospital.

What can affect the test results?

Various factors influence the results.

1. For example, people of the Negroid race usually have a fairly high content of AF protein in the body, while representatives of the Mongoloid race have a low content.
2. The presence of diseases of the endocrine system (diabetes, biotin intake, viral diseases) that have recently occurred in the patient is also taken into account.
3. Minor deviations from the norm are also possible in pregnant women who are expecting twins or more children.

In order to protect yourself in time from the appearance of cancer and other oncological diseases, it is necessary to approach such tests responsibly and follow the instructions of doctors.

Normal AFP tumor marker

On average, test results are provided 1-3 days after blood collection. The results must be deciphered by a doctor who takes into account the patient’s gender, age, concomitant diseases, etc.

The tumor marker standards are as follows:

In pregnant women:

In addition to the unit of measurement IU/ml, ng/ml is also used. If the results were given in ng/ml, then they can be converted to IU/ml using the formula: 1 ng/ml * 0.83 = IU/ml.

Any deviations from the norms in medicine are considered a pathology and a reason for a more extensive examination. But minor deviations from the norm are acceptable in the following cases:

1. As medical studies show, the Negroid race has a higher content of α-fetoprotein compared to people belonging to the Mongoloid race;
2. If a person was tested a few days after suffering a viral or bacterial infection, then this fact can also affect the results of the tests;
3. During multiple pregnancies, doctors allow deviations from the norm in the AFP tumor marker, but they are insignificant.

How to decipher A-fetoprotein data

This is a special protein synthesized by the liver and gastrointestinal tract of the embryo. This substance is first produced in the corpus luteum of the ovary, and from the second month it is produced by the fetus.

Alpha-fetoprotein helps protect the fetus from rejection by the mother. The concentration of AFP in a woman’s blood depends on the intrauterine development of the fetus and the duration of pregnancy. Its greatest significance is observed in the last months of pregnancy.

This protein performs important functions in the body of a pregnant woman:

• participates in the transportation of substances necessary for the development and growth of the fetus;
• ensures the formation of surfactant (a substance that coats the respiratory organs, which is necessary for the child to breathe after birth);
• normalizes pressure in the blood vessels of the fetus;
• prevents the impact of a woman's estrogen on the fetus.

AFP begins to enter the maternal blood in the second month of pregnancy as a result of absorption from the amniotic fluid. The substance penetrates into it when the fetus excretes urine.

The normal level of AFP tumor markers in the human body directly depends on his gender and age; reference values ​​are indicated in IU/ml.

If a patient has prostate cancer, the level of the PSA tumor marker in his body increases significantly. Antigen normal levels directly depend on the patient’s age.

• The norm for men who are in the age group of 17-40 years is a PSA value below 0.33 ng/ml.
• Normal values ​​for men 41-50 years of age are below the maximum permissible limit of 0.42 ng/ml.
• Normal results for men 51-60 years old should not exceed 0.49 ng/ml.
• The norm for elderly men aged 61-90 years is no higher than 0.87 ng/ml.
  

  Reliability of PSA test results

  Not in all cases, an increase in the concentration of the PSA tumor marker serves as an indicator of prostate cancer. It has been proven that a certain increase in prostate specific antigen levels can be observed in diseases such as prostate adenoma and prostatitis. In this case, doctors must not only diagnose total PSA; they also check the concentration of its free fraction, as well as the ratio of free antigen to total PSA. The norm for free PSA in the male body is within 0.4-0.5 ng/ml. If a patient has a benign disease, the ratio of total and free PSA is more than 15%. If the patient has an oncological process, this figure will be less than 15%.

In order to independently understand the test results, the patient must know the normal values ​​of the CEA tumor marker and have an idea of ​​what a deviation from the norm may mean.

The normal levels of this substance are the same for both sexes; the patient’s age also does not play a role. Normally, the concentration of CEA in the body of a man or woman should not exceed 6.5 ng/ml. Normal CEA values ​​in blood serum indicate a low risk of developing cancer. The result may also be due to the fact that the testing is not sensitive to a specific tumor type.

The results are deciphered in the same laboratory where the research took place. A blood test for AF protein is deciphered depending on the method of examination. The description of the results should be carried out according to the standard generally accepted in the diagnostic center. Reference values ​​for A-fetoprotein levels may vary slightly between institutions. Certain values ​​are taken as the normal level of AFP for different sexes and ages.

1. Testing for AFP is a tumor marker that is normal in adult women and men.

The presence of no more than 7.0 ng/ml of AF protein in the body is considered normal. Indicators that exceed the above norms can be considered an increased level of the tumor marker AFP. What could this mean?

If you have elevated levels of A-fetoprotein in your blood, this may be a symptom of certain diseases of oncological origin:

• hepatocellular carcinoma;
• liver metastases;
• germ cell malignancies in the ovaries or testicles;
• colon cancer;
• malignant tumors in the pancreas;
• lungs' cancer.
• In addition to cancer, the following gynecological ailments can provoke an increase in A-fetoprotein:
• various hepatitis;
• hepatic cirrhosis;
• blockage of bile ducts;
• liver damage by alcohol;
• telangiectasia syndrome;
• tyrosinemia, inherited.

In such cases, the norm of A-fetoprotein is allowed up to 10 IU/ml. If the result of the AFP tumor marker in the body shows more than 400 IU/ml, you can decide that this is a symptom of cancer. A high level of this protein in pregnant women at 14-16 weeks of gestation gives a signal that the child may be born with congenital abnormalities or the woman in labor has a disease.

It is important to properly prepare for testing

Quite often, such results cause alarming thoughts in people, in particular in pregnant girls. There is no need to panic right away. Exceeding the norm of one protein A-fetoprotein does not provide confidence in either deviations or deficiencies in the child’s development. The likelihood of Down syndrome developing in a fetus with a high AFP level is low.

If the amount of A-phytoprotein is exceeded, there is no guaranteed likelihood of cancer. But you shouldn’t put the problem off until later either. Exceeding normal values ​​indicates that it is time to carry out various examinations of the expectant mother or another patient who has a problem. Only a set of studies will allow us to find out the exact reason for the increased concentration of alpha-fetoprotein in a particular person.

conclusions

From all of the above, we can conclude that an analysis to determine the level of the tumor marker AFP can only indirectly indicate the presence of anomalies in the intrauterine development of the fetus. In any case, you need to undergo several screening tests at certain stages of pregnancy.

It should also be noted that in oncology, the AFP tumor marker, or any other type of tumor marker, is not used as a diagnostic tool, but is only one of the indicators of a possible cancer disease. Most often, the dynamics of its growth are observed to assess the effectiveness of cancer treatment.