As the “awareness of cancer prevention” among the public has been improved, tumor marker test is becoming an increasingly popular item. After get their test results, some physical examinees would be false alarmed by the test result due to mistaken interpretation. How should we accurately interpret the various tumor marker tests? Does an abnormal test result mean cancer? Let’s listen to how the doctors will explain.
Tips
common tumor markers
1. EBA (Epstein Barr Virus) VCA/IgA antigen and EA/lgA antigen
They are mainly used for early detection of nasopharynx cancer through blood test. Nasopharynx is also called “Canton cancer” due to its high incidence among Guangdong natives. 80% of early stage nasopharynx cancer can be detected though EBA VCA/lg antigen and EA/lgA antigen testing; hence, it serves a good warning function.
2. HPV (human papillomavirus)
HPV is mainly used for early detection of cervical cancer through cervical secretion examination. HPV infection is the major cause for cervical cancer and its precancerous lesions. At present, high risk HPV testing is an important means for screening cervical cancer and its precancerous lesions. According to statistics, 99.7 % cervical cancer patients showed HPV positive. It is advised to receive antiviral prophylaxis and regular cytopathology examination when HPV is detected during physical examination.
3. AFP (Alpha fetoprotein)
AFP is mainly used for early detection of liver cancer through blood test. The risk of getting liver cancer among chronic hepatitis B (CHB) patients and chronic hepatitis C (CHC) patients is much higher than that of non-carriers. Early detection of 60%-70% liver cancer can be obtained if the high risk group could do AFP test on a regular basis. To avoid missing detection of AFP negative hapatocellular carcinoma, physical examinees are advised to receive fine-needle aspiration biopsy, imageological examination and other tumor marker tests.
4. CA 125
CA 125 is mainly used for early detection of ovarian cancer though blood test. 50%-60% of ovarian cancer could be detected through CA 125 test.
5. CEA (carcino-embryonic antigen)
CEA is mainly used for detection of lung cancer and gastrointestinal cancer through blood test. 70%-80% lung cancer and gastrointestinal cancer could be detected through CEA test.
Special reminders
Having cancer cells doesn’t mean being diagnosed with cancer
Many physical examinees would consult with the doctor about the tumor maker test result asking, “Why the values of my tumor marker test isn’t zero? Does that mean I have a mass in my body?” In fact, about 10,000 cancer cells will be produced in human body everyday; therefore, the values of almost all tumor marker tests will not stand at zero. Indeed, there is a normal range of tumor marker values. It’s normal as long as the values are within the normal range. Having cancer cells in human body doesn’t mean being diagnosed with cancer. As the immune function in human body can swallow cancer cells in a timely manner, common people are not susceptible to cancer.
False positive and false negative
Some physical examinees would assume that they are diagnosed with cancer even if a certain tumor marker slightly exceeds the normal range. Actually, the increase of a single tumor marker cannot serve as the sole criteria for cancer diagnosis, especially when the value is just slightly higher than normal range. Physical examinees are kindly advised to receive re-examinations at specialized hospital or big hospitals. The accuracy of examination result bears certain relation with the agent involved and examination procedure. Low reagent quality or nonstandard examination procedure might lead to false positive and false negative or inaccuracy of test result.
In addition to the above-mentioned factors, the physical examinees themselves will have impact on the test result. The following factors might also contribute to the inaccuracy of test result. For example, the physical examinees have rheumatoid arthritis or excessive drinking or they had sumptuous meal, overwork the night before the examinations. If the physical examinees had seafood or greasy food just before the examination, the blood serum will be in a greasy state. After mixed with reagent, its adhesion will be affected; hence, the accuracy of test result will be adversely affected. In addition, when human body has inflammation or when some chronic diseases attack, the values of certain tumor markers will be increased. Therefore, further examination needs to be done to identify the accuracy of the test. If re-examination shows that the value of tumor marker is decreasing and even to normal range, physical examinees don’t have to be worried about the result.
Be alert when tumor marker doubles or keeps increasing
If tumor marker increases abnormally, especially when it doubles the normal range or keeps increasing through dynamic observation, it means that cancer cells are accumulating. Physical examinees are advised to receive B ultrasound, CT scan, MRI or fine needle aspiration cytopathology to eliminate the possibility of cancer under the instruction of doctors.
Upon seeing the abnormal tumor marker, some physical examinees would be terrified and ask doctor to arrange PET-CT scan. They won’t be feel relieved unless they have a scan from head to feet. According to experts, it is inadvisable to have such a mentality to have the examination at one go. Cancer screening should follow the principle of being simple and being economic. Physical examinees should start from B ultrasound, liver function test, kidney function test and blood routine test. If examinations suggest any abnormality, physical examinees should go for further precision examination. To receive CT scan or PET-CT scan at the very beginning is unnecessary; instead, physical examinees would be exposed to extra radiation. Medical radiation itself is a kind of carcinogenic factor that might induce or accelerate tumor recurrence.
Don’t ignore the alarm issued by human body
Many physical examinees would be rest assured after no tumor is detected in human body even if abnormal tumor marker is present. Doctors warn that physical examinees of this type should not treat it lightly, especially when tumor marker shows persistently abnormal as it means human body is issuing alarms that body conditions are suitable for the survival of cancer cells; the immune system cannot eliminate cancer cells in a timely manner and cancer cells in human body is much more than normal range.
Physical examinees of this type are advised to adjust their way of life. Many physical examinees would have the value of tumor marker restored to normal range after a period of life adjustment, such as staying up less, reducing social engagement, having less meat and more vegetable and fruits.