In recent years, the frequency of hearing someone suffering from cancer has become higher and higher. The high risk of cancer death and the painful treatment process all make people feel desperate and pale.
The best way to fight cancer is "early examination, early detection and early treatment". Therefore, physical examination has become a popular choice at present.
Many people will have a "tumor marker examination" during physical examination, but after getting the results, it shows that the tumor marker index increases, and they often feel anxious.
So, does the increase of tumor markers necessarily mean cancer? What should we do when tumor markers are elevated?
Is elevated tumor markers cancer?
The rise of some tumor markers is earlier than the emergence of tumor clinical symptoms. Therefore, tumor markers are beneficial to early detection of tumor signs and help doctors diagnose and treat early, so as to improve the curative effect.
In addition to early detection of cancer, tumor markers can also be used in the following aspects: differential diagnosis after tumor related symptoms or suspicious masses, judgment of tumor biological characteristics and disease stage, observation of curative effect and prognosis after tumor treatment, suggesting tumor recurrence and metastasis, etc.
However, the increase of tumor markers is not necessarily caused by tumor. Tumor markers exist not only in malignant tumors, but also in some benign tumors, embryonic tissues and normal tissues.
Tumor diagnosis can not rely on tumor markers alone, but needs comprehensive judgment through clinical examination, imaging examination, endoscopy or surgical exploration, and pathological diagnosis is the "gold standard" of tumor diagnosis.
In addition, even if the tumor markers are normal, the tumor is not excluded. Some tumors do not increase tumor markers from beginning to end. Some tumor markers are normal in the early stage of the disease and will not increase until the disease develops to a certain extent.
So far, scientists have not found any ideal tumor markers. At present, the sensitivity and specificity of tumor markers used in clinic are less than 100%, that is, each tumor marker can correspond to one or more cancers, but not one-to-one.
The increase of tumor markers is not only related to tumor occurrence and development, but also affected by the following factors:
Benign disease
Such as chronic liver disease, chronic kidney disease, cholelithiasis, diabetes, and taking certain drugs. For example, in patients with hepatorenal cysts, the serum carcinoembryonic antigen (CEA) and pancreatic and colorectal cancer related antigen CA19-9 will increase, or even exceed the normal value several times.
Physical inflammation / physiological changes / living habits
A little inflammation of the body will also lead to the increase of tumor markers, and physiological changes such as pregnancy, smoking, alcoholism and bad living habits will also lead to the increase.
Too close contact with pets can also lead to the increase of tumor markers, which is called false positive in medicine.
Detect interference
Contamination during blood drawing, red blood cell rupture caused by blood drawing, improper preservation of samples, reagent differences and non-standard detection will also interfere with the test results.
Some tumor cells secrete few tumor markers, which will also affect their accuracy in early cancer screening.
Take carbohydrate antigen 199 (CA199) as an example. In addition to malignant tumor factors, the following conditions will lead to its increase:
CA199 itself is at a high level in bile, pancreatic juice and intestinal digestive juice of some healthy people.
CA199 will also increase in patients with pancreatitis, hepatitis, biliary inflammation, obstructive diseases, renal failure and other diseases.
If the test kit is different, the test time is too long, and the blood sample is damaged, the index may also rise.
What if tumor markers rise?
First of all, it depends on the extent of the increase. If it slightly exceeds the normal value, it is generally considered as "slight increase"; If it is a significant increase, doctors often call it a "meaningful" increase.
The increase of tumor markers several times, more than ten times and dozens of times is of course more meaningful than only a little and double, but this is not absolutely 100%.
For example, in some chronic hepatitis, alpha fetoprotein (AFP) can be as high as more than 1000ug / L (normal < 30ug / L), but enhanced MRI does not find liver mass, and AFP decreases with the improvement of liver function, which can rule out liver cancer. Therefore, the increase of tumor markers should be combined with clinical comprehensive judgment.
Secondly, it should be combined with ultrasound, CT, magnetic resonance imaging or gastrointestinal endoscopy.
For example, imaging examination or gastrointestinal endoscopy found that there was an objective basis for the existence of tumor, and the tumor markers in the patient‘s blood increased again, and increased to more than twice the upper limit of normal, suggesting that there is a great possibility of malignant tumor.
If the tumor marker is less than 1.5 times of the upper limit of normal, it is generally considered to be slightly elevated, and there is no basis for imaging or gastrointestinal endoscopy. It is not necessarily cancer, which can be observed regularly.
Therefore, the tumor markers are elevated, and further imaging or gastrointestinal endoscopy is needed to find the objective basis for the existence of the tumor.
Finally, it is important to dynamically observe tumor markers. Especially when the increase of tumor markers is small, it is more valuable to dynamically observe its change trend. Generally, the tumor markers are rechecked once 1 ~ 2 months, and it is necessary to detect other related tumor markers.
If the tumor markers increase gradually or continuously, or other tumor markers also increase, it is necessary to have another imaging or gastrointestinal endoscopy or more precise examination after 3 months, because small tumors may not be found at that time, and they may be found after 3 months.
For example, in patients with liver cirrhosis, the AFP titer is continuously low and increased (below afp200ug / L). Although no liver space occupying lesions are found in enhanced magnetic resonance imaging, liver cancer should still be highly suspected and further hepatic arteriography should be performed.
If the results are generally stable after repeated review, and do not increase from time to time, allowing a small fluctuation up and down, or the tumor marker decreases gradually, it usually means that it is not caused by cancer, that is to say, your index has no direct relationship with cancer.
Which tumor markers should be paid special attention to?
Alpha fetoprotein (AFP) main target: liver cancer
Alpha fetoprotein is the best marker for the diagnosis of primary liver cancer, with a positive rate of 60% ~ 70%. Serum alpha fetoprotein > 400 μ G / L for 4 weeks, or 200 μ g-400 μ G / L for 8 weeks, combined with imaging examination, the diagnosis of primary liver cancer can be made.
To diagnose liver cancer, there are two detection indicators, one is B-ultrasound, and the second is alpha fetoprotein. The sudden increase of alpha fetoprotein indicates the possibility of liver cancer.
Recommendations for liver cancer screening
Screening should be carried out for high-risk groups of liver cancer over 35 years old for men and over 45 years old for women. The combination of serum alpha fetoprotein (AFP) and liver B-ultrasound was used for screening once every 6 months.
Prostate specific antigen (PSA) main target: prostate cancer
Prostate specific antigen is a glycoprotein synthesized by human prostate epithelial cells and secreted into seminal plasma. PSA mainly exists in prostate tissue, not in women. The content of PSA in normal men‘s serum is very low, and the serum reference value is less than 4 μ g/L。
PSA has organ specificity, but not tumor specificity. The positive rate of prostate cancer was 80%. The level of serum PSA increased in different degrees in benign prostate disease.
Recommendations for prostate cancer screening: Serum PSA test shall be conducted once every 2 years, and the termination time of PSA test shall be determined according to the patient‘s age and physical condition.
Carcinoembryonic antigen (CEA) main targets: colon cancer, gastric cancer, etc
It is a broad-spectrum malignant tumor marker with strong specificity, which is mainly used for the auxiliary diagnosis of gastrointestinal tumors, lung cancer and other malignant tumors. If it is slightly elevated, it can be rechecked after half a month; If carcinoembryonic antigen increases ≥ 8 μ G / L, or progressive increase, it is recommended to go to gastroenterology department for further diagnosis and treatment as soon as possible. Other patients such as heavy smokers, rectal polyps and colitis may also be slightly increased.
The positive rates of CEA in malignant tumors were colon cancer (70%), gastric cancer (60%), pancreatic cancer (55%), lung cancer (50%), breast cancer (40%), ovarian cancer (30%), and uterine cancer (30%).
Finally, we summarize the following points about "tumor markers":
1: The increase of tumor markers may indicate the risk of tumor. It is recommended to go to the hospital for reexamination.
2: Tumor markers can only assist in the diagnosis of cancer, and the diagnosis needs further examination.
3: Normal tumor markers can not rule out cancer. Do not rely too much on tumor marker examination.
4: Early detection of cancer can not only rely on tumor markers, but also need to carry out targeted cancer prevention screening according to different populations.
5: Special attention should be paid to the abnormal increase of AFP, PSA and CEA.
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