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2023 Author: Benjamin Dyson | [email protected]. Last modified: 2023-05-27 20:34
To identify cancer, the doctor may request the measurement of tumor markers, which are substances produced by the cells or by the tumor itself, such as AFP and PSA, which are elevated in the blood in the presence of certain cancer types. Know the signs and symptoms that may indicate cancer.
The measurement of tumor markers is important not only to detect cancer, but also to assess tumor development and response to treatment.
Although tumor markers are indicative of cancer, some benign situations can lead to their increase, such as appendicitis, prostatitis or prostate hyperplasia and, therefore, in most cases it is necessary to perform other tests to confirm the diagnosis, such as ultrasound or magnetic resonance imaging, for example.
In addition, the values of the tumor indicators of the blood test vary according to the laboratory and the patient's sex, it is important to take into account the laboratory reference value. Here's how to understand the blood test.
Some of the most requested tests by the doctor to identify cancer are:
1. AFP
What it detects: Alpha-fetoprotein (AFP) is a protein whose dosage can be ordered to investigate tumors in the stomach, intestine, ovaries or the presence of metastases in the liver.
Reference value: Usually when there are malignant changes the value is greater than 1000 ng/ml. However, this value can also be increased in situations such as cirrhosis or chronic hepatitis, for example, its value being close to 500 ng/ml.
2. MCA
What it detects: Carcinoma-associated mucoid antigen (MCA) is usually ordered to check for breast cancer. Know how to recognize the signs of breast cancer.
Reference value: In most cases it can indicate cancer when its value is greater than 11 U/ml in the blood test. However, this value may be increasing in less serious situations, such as benign tumors of the ovary, uterus or prostate.
Usually, the physician also requests the measurement of the CA 27.29 or CA 15.3 marker to monitor breast cancer and verify the response to treatment and the chance of recurrence. Understand what it is for and how the CA 15.3 exam is performed.
3. BTA
What it detects: Bladder Tumor Antigen (BTA) is used to help detect bladder cancer and is usually measured along with NMP22 and CEA.
Reference value: In the presence of bladder cancer, the test has a value greater than 1. The presence of BTA in the urine, however, can also be elevated in less serious problems such as inflammation of the kidneys or urethra, especially when using a urinary catheter.
4. PSA
What it detects: Prostate antigen (PSA) is a protein normally produced for the prostate, but in the case of prostate cancer its concentration may be increased. Learn more about PSA.
Reference value: When the concentration of PSA in the blood is greater than 4.0 ng/ml may indicate the development of cancer, and when it is greater than 50 ng/ml ml, may indicate the presence of metastases. However, to confirm cancer, it is necessary to perform other tests such as digital rectal examination and prostate ultrasound, since the concentration of this protein can also be increased in benign situations.
5. CA 125
What it detects: CA 125 is a marker widely used to check the chance and follow the development of ovarian cancer. The dosage of this marker must be accompanied by other tests so that the correct diagnosis can be made. Learn more about CA 125.
Reference value: It is usually a sign of ovarian cancer when the value is greater than 65 U/ml. However, the value can also be increased in the case of cirrhosis, cysts, endometriosis, hepatitis or pancreatitis.
6. Calcitonin
What it detects: Calcitonin is a hormone produced by the thyroid that can be increased mainly in people with thyroid cancer, but also in people with breast or breast cancer. lung, for example. See how the calcitonin test is performed.
Reference value: It can be a sign of cancer when the value is greater than 20 pg/ml, but the values can also be altered due to problems such as pancreatitis, disease of Paget and even during pregnancy.
7. Thyroglobulin
What it detects: Thyroglobulin is normally elevated in thyroid cancer, however, for the diagnosis of thyroid cancer other markers, such as calcitonin and TSH, for example, as thyroglobulin can be increased even in people who do not have the disease.
Reference value: Normal thyroglobulin values are between 1, 4 and 78 g/ml, above that may be indicative of cancer. See what the symptoms of thyroid cancer are.
8. CEA
What it detects: Carcinoembryonic antigen (CEA) can be dosed for different types of cancer, being normally elevated in bowel cancer, affecting the colon or rectum. Learn more about bowel cancer.
Reference value: To be indicative of cancer, the concentration of CEA needs to be 5 times higher than the normal value, which is up to 5 ng/mL in smokers and up to 3 ng/mL in non-smokers. Understand what the CEA exam is and what it is for.
In addition to these blood tests, other hormones and proteins can be evaluated, such as CA 19.9, CA 72.4, LDH, Cathepsin D, Telomerase and Human Chorionic Gonadotropin for example, which have altered reference values when is developing cancer in some organ.
Magnetic resonance
How to confirm the diagnosis of cancer
In case of suspecting cancer, it is necessary to confirm the diagnosis, normally requested by the doctor complementary imaging tests, such as:
- Echography: Also known as ultrasound, which is an exam that allows you to detect lesions in organs such as the liver, pancreas, spleen, kidneys, prostate, breast, thyroid, uterus and ovaries;
- Radiography: It is an exam performed through X-ray, which helps to identify changes in the lung, spine and bones;
- Magnetic resonance imaging: It is an imaging test that detects changes in organs such as the breast, blood vessels, liver, pancreas, spleen, kidneys and adrenals.
- Computed Tomography: It is performed when there are changes in the X-ray and is usually requested to evaluate the lungs, liver, spleen, pancreas, joints and pharynx, for example.
In most cases, the diagnosis is confirmed by combining several tests, such as patient observation, blood test, MRI and biopsy, for example.
