Cancer cells produce more intensively certain protein substances, of which the cells of a healthy, non-diseased body produce very little. These substances can be detected in the blood through tests. They are called cancer markers.
Small amounts of various cancer markers are found in the blood of a healthy person. In the case of one or another cancer, its cells begin to intensively secrete the corresponding cancer markers, then more of them are found in the blood - the level is above normal.
The level of cancer markers in the blood can increase not only in oncological diseases, but also in some other benign diseases or benign tumors.
Sometimes, even with cancer, the tumor does not produce cancer markers, their level in the blood is not increased.
When are blood tests for cancer markers used:
When determining whether there is a suspicion of cancer in the relevant organ
Evaluating the effectiveness of cancer treatment
Monitoring patients after oncological disease treatment for disease recurrence or progression
It is very important to know that the fact that the patient has an increased level of one or another cancer marker in the blood is not enough to diagnose cancer. Maybe the level of the marker increased not because of cancer, but for another reason and on the contrary - the person may already have cancer, but the level of the marker in the blood has not increased. Therefore, when an increased level of any marker in the blood is detected, one can only suspect one or another malignant disease, the presence of which must be proven by conducting other necessary tests.
- An ovarian cancer marker (CA 125) is usually elevated in epithelial ovarian adenocarcinoma. The detected increased level of it in the blood prompts to examine the ovaries in more detail and to detect early stages of ovarian cancer in some patients. Determining the level of the marker in the blood can be useful both for the initial diagnosis of ovarian cancer, as well as for the effectiveness of the treatment of the disease and for monitoring the course of the disease after treatment.
- Carcinoembryonic antigen (CEA) - its level in the blood is studied during clinical monitoring of many types of cancer (it is a non-specific marker for determining the primary tumor, but it proves the malignant process itself, used in combination with specific cancer markers). It is usually studied by monitoring tumors of the stomach, intestines, breasts, lungs, and pancreas after treatment. The CEA test is considered the best non-invasive method for monitoring and predicting the course of colon and rectal cancer. In the postoperative period, this test is sometimes a more sensitive parameter than computed tomography or endoscopy. In smokers, this marker may be increased even in the absence of oncological disease.
- Gastric cancer marker (Ca 72-4) - optional to monitor the progress of gastric, mucosal ovarian carcinoma and gastrointestinal tract cancer during treatment.
- For the breast cancer marker (Ca 15-3) - the main indications for its investigation are the screening of breast cancer patients during treatment and follow-up after treatment for disease recurrence and metastases.
- Pancreatic cancer and digestive tract tumor marker (Ca 19-9). It is a highly specific marker for carcinoma of the pancreas and biliary tract. For everyone over 45 age patient who has ailments in the upper part of the abdomen (pain, discomfort, pressure), it is recommended to undergo this examination. It is worth determining the amount of this marker if unclear, vague signs of the disease last for two to three weeks, and no obvious pathological processes can be found.
- Alpha-fetoprotein (AFP), a marker for hepatocellular carcinoma and testicular cancer, is useful for screening patients for primary liver cancer, which usually develops in patients with cirrhosis or chronic hepatitis, and for monitoring the course of the disease. AFP can be chosen as one of the methods to help identify testicular cancer, and especially to monitor its progress.
- Human chorionic gonadotropin (β-hCG), a marker of germ cell tumors and trophoblastic diseases, is measured in the blood as one of the ways to help identify tumors of embryonic cells, especially testicles, as well as to monitor the course of the disease. The amount of the marker is also increased in trophoblastic tumor tumors.
- Thyroglobulin (TG), a marker of differentiated thyroid cancer, is a blood test used in the diagnosis of differentiated thyroid cancer (papillary-follicular carcinoma), and especially to monitor the progress of this cancer.
- Dimeric protein (S 100) - found in many melanoma cells, its blood levels are measured in the treatment of patients with malignant melanoma. May be useful in confirming recurrence of melanoma.
- Generic procollagen-like propeptide (P1NP) - the true marker of bone formation, appears in the blood during the formation of collagen, which makes up 90% of the body. bone mass. Testing of P1NP levels in the blood makes it possible to detect early bone metastases of prostate and other cancers earlier than is possible with bone scintigraphy.