September 30, 2022

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Liver cancer tumor markers: AFP vs DCP

Liver cancer tumor markers: AFP vs DCP.



 

Liver cancer tumor markers: AFP vs DCP.

Early tumor diagnosis is still a hot and difficult point in tumor diagnosis and treatment.

Currently, commonly used tumor markers are also elevated in the serum of some normal people, and in the blood of some cancer patients Instead, he remained silent and did not rise from beginning to end.

This kind of erraticness often confuses tumor doctors and makes diagnosis more difficult.

 

Today we will talk about the tumor markers of liver cancer, alpha-fetoprotein (AFP) and abnormal prothrombin (DCP).

 

Liver cancer tumor markers: AFP vs DCP

 

 

 

AFP

Where does AFP come from?

Alpha-fetoprotein (AFP) is a serum glycoprotein synthesized by the liver and yolk sac during the early stage of fetal development, and it gradually disappears soon after birth.

Therefore, the level in adult blood is extremely low.

 

After the occurrence of liver cancer, the abnormally mutated liver cancer cells will continuously secrete this protein and be released into the blood, increasing its level.

 

AFP and liver cancer diagnosis

AFP is a recognized indicator for early diagnosis and screening of primary liver cancer. When it is ≥ 400ug/L, it is highly indicative of liver cancer.

However, after pregnancy, chronic or active liver disease, gonad embryo-derived tumors, and gastrointestinal tumors need to be excluded, AFP will also increase to varying degrees in this type of disease.

 

When the serum AFP is slightly elevated, dynamic observation should be made. For example, in patients with chronic hepatitis and cirrhosis, the increase in serum AFP level is mostly transient or fluctuating, while the increase in serum AFP in liver cancer patients is mostly stable and continuous.

 

How to set the AFP diagnostic threshold?

Research shows:

If 400ug/L is used as the diagnostic threshold of liver cancer, the prediction specificity is more than 90%, but the sensitivity is less than 50%, which will cause a great missed diagnosis.

The missed diagnosis rate is usually about 40%. Many HCC patients only have a slight increase in AFP, especially for small liver cancer (tumor diameter <3 cm), and their AFP levels may not change.

 

If 400ug/L is used as the diagnostic threshold of liver cancer, the prediction specificity is more than 90%, but the sensitivity is less than 50%, which will cause a great missed diagnosis.

The missed diagnosis rate is usually about 40%. Many HCC patients only have a slight increase in AFP, especially for small liver cancer (tumor diameter <3 cm), and their AFP levels may not change.

 

If 20 μg/L is used as the diagnostic threshold, the diagnostic predictive sensitivity increases to 73.6%, while the specificity is greatly reduced. If the normal value limit (<20ug/L) is used as the diagnostic criteria for primary liver cancer, the false positives are relatively high , It is easy to cause misdiagnosis, but we consider it can be used as a screening index for primary liver cancer and used in high-risk population screening together with other imaging tests.

 

If 20 μg/L is used as the diagnostic threshold, the diagnostic predictive sensitivity increases to 73.6%, while the specificity is greatly reduced. If the normal value limit (<20ug/L) is used as the diagnostic criteria for primary liver cancer, the false positives are relatively high , It is easy to cause misdiagnosis, but we consider it can be used as a screening index for primary liver cancer and used in high-risk population screening together with other imaging tests.

 

There are literature reports:

If 200ug/L is used as the diagnostic threshold, compare it with the 400 µg/L group as follows:

 

The specificity of the two is basically the same, and the sensitivity of 200ug/L is significantly better than that of the 400 µg/L group.

Therefore, it is believed that 200 µg/L is better than 400 µg/L in the diagnosis of primary liver cancer by AFP.

 

The specificity of the two is basically the same, and the sensitivity of 200ug/L is significantly better than that of the 400 µg/L group.

Therefore, it is believed that 200 µg/L is better than 400 µg/L in the diagnosis of primary liver cancer by AFP.

 

Other functions of AFP

In addition to being a clinical diagnostic marker, AFP can be used as a prognostic indicator.

 

AFP In patients with liver cancer associated with HBV infection, the higher the preoperative AFP, the lower the postoperative survival rate. However, this phenomenon has not been observed in other causes of liver cancer.

When AFP is used as a prognostic indicator of liver cancer, it is necessary to distinguish between HBV-related liver cancer and non-HBV-infected liver cancer.

 

In addition, for AFP-positive liver cancer undergoing radical surgery, AFP should fall to negative within a certain period of time.

If postoperative recurrence or metastasis occurs, AFP may rise again.

However, the original AFP-positive HCC patients can also be AFP-negative when they relapse, and the original AFP-negative patients can also be AFP-positive, and postoperative testing needs to be combined with imaging.

 

DCP

AFP still has shortcomings, DCP can make up

For AFP-negative liver cancer, diagnosis requires the use of other serological indicators, such as abnormal prothrombin (DCP), which is more commonly used at present.

Compared with alpha-fetoprotein that is more than half a hundred years old, DCP can be regarded as a post-80s. It was first recognized in 1984. Described as a tumor marker (although the name seems to be related to blood clotting).

 

DCP is synthesized in the liver. When vitamin K is deficient or when certain anticoagulant drugs are taken, it is abnormally elevated.

Another name is vitamin K deficiency or antagonist-induced protein-II (PIVKA-II). DCP is caused by incomplete carboxylation of precursors during the process of liver synthesis of prothrombin, so the full name is de-γ-carboxy prothrombin.

 

Serum DCP levels in patients with liver cancer increase when liver cells become cancerous, carboxylase gene expression levels decrease, or carboxylase inhibitors are present in liver cells.

 

DCP has better diagnostic performance than AFP

Although both AFP and DCP are liver cancer-specific tumor markers, there is no significant correlation between DCP and AFP, indicating that the value of DCP does not depend on changes in AFP and can independently reflect the status of patients with liver cancer.

 

Studies have shown that DCP is significantly better than AFP in the diagnosis of HBV-related HCC, especially for the diagnosis of early liver cancer.

DCP also plays a role in the early screening of AFP-negative hepatocellular carcinoma patients.

 

DCP is positively correlated with tumor severity

In patients with tumors ≥ 5 cm in diameter, serum DCP is significantly increased, and the concentration is positively correlated with TNM staging.

In patients with HCC associated with HBV infection, DCP has a significant correlation with tumor diameter.

 

In short, serum DCP levels in patients with liver cancer are related to tumor number, size, clinical stage, distant metastasis, vascular invasion, and pathological grade.

It can assist clinicians in judging tumor aggressiveness, assess prognosis, and choose the best treatment for patients the way.

 

Although DCP is good, it also has shortcomings

Patients with vitamin K deficiency, drinking alcohol, or taking warfarin and other anticoagulants can all lead to an abnormal increase in DCP.

In clinical applications, these factors must be fully considered to avoid interference with the diagnosis.

 

The combined application of AFP and DCP in the diagnosis of liver cancer is more accurate than DCP or AFP alone.

Studies have shown that the combined detection of AFP and DCP can increase the diagnostic sensitivity of primary hepatocellular carcinoma to 95.7%, so there is Scholars believe that this kind of joint detection will be a common diagnostic mode at home and abroad in the future.

 

However, although the sensitivity of combined diagnosis is greatly improved, the specificity will inevitably decrease, which can easily lead to misdiagnosis due to the presence of false positives.

Therefore, the road to early diagnosis of liver cancer still has a long way to go.

 

 

 

 

Liver cancer tumor markers: AFP vs DCP.

(source:internet, reference only)


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