Circulating tumor cells: help early detection and treatment of tumors

Cancer-Cancer, the number one killer of human health, is a daunting word
.

When talking about cancer, the discoloration is because when it destroys the body recklessly and takes lives ruthlessly, you are too helpless and helpless! The medical technology of this era has made great progress, but the incidence and death rate of cancer are still increasing day by day.
According to statistics 1, in 2020, China will have about 4.
57 million newly diagnosed cancers and about 3 million deaths from cancer, and the data in 2015 In comparison, the number of cases and deaths have increased
.

And regardless of urban and rural areas, cancer ranks first among the causes of death among Chinese residents
.

However, for this big killer, we are not powerless! Cancer is a series of diseases of malignant proliferation of unhealthy cells, also called malignant tumors.
In fact, it is a chronic disease.
Its occurrence and development are not overnight, but a relatively long process.
Broadly speaking, tumor occurrence and development include early, early, and Three stages in the middle and late stages
.

In the early stage, it is often "moisturizing things silently" and difficult to be found, but once discovered, it is often in the late stage.
At this time, the best treatment opportunity has been missed, the treatment effect is poor, and the cure rate is also low
.

For tumors, the earlier they are detected, the higher the cure rate of the tumors, and the longer the patient's survival period
.

Taking lung cancer with the highest incidence in China as an example, the 5-year survival rate (clinical cure rate) of patients with early lung cancer can reach 70-90%, while the 5-year survival rate of patients with advanced lung cancer is only about 10%2
.

At present, there is no clear drug that can cure tumors, but the medical community agrees that early detection and early treatment of tumors are the key to tumor treatment
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So how do we find the clues of the tumor and find the tumor early? Circulating Tumor Cell (CTC) detection that breaks the limitations of traditional detection methods can help us
.

What is CTC? CTC is a tumor cell that is shed from the primary tumor or metastasis and enters the blood circulatory system (Figure 1).
CTC is closely related to tumor activity, and its number can directly reflect the state of tumor occurrence and development, 2007 , American Society of Clinical Oncology (ASCO) included CTC as a tumor marker
.

At present, many domestic and foreign guidelines have also included CTC, and clearly pointed out the clinical value of CTC
.

CTC detection uses advanced circulating cell detection technology to capture CTCs in human peripheral blood and analyze and count them
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The test usually only needs to draw a tube of blood, which can make up for the limitation of tumor tissues that are difficult to obtain.
It can be repeatedly sampled and has almost no side effects.
It has been widely used in clinical practice in Europe, America and China.
It can be used for lung cancer, hepatobiliary pancreatic cancer, esophageal cancer, and stomach.
During the diagnosis and treatment of solid tumors such as colorectal cancer, urinary system tumors, breast cancer, nose and throat tumors, and tumors outside the head and neck
.

So what role does CTC play in the diagnosis and treatment of tumors? High-risk population: "Detectives" studies in the early detection of tumors have shown3 that tumor cells can be detected in the blood when the tumor grows to 2mm, but imaging or other examination indicators may not be abnormal at this time, because imaging examinations Usually only tumors larger than 2mm can be found
.

Conventional tumor markers, such as cancer antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), etc.
, detect tumor cell secretions, which can only be detected in the middle and late stages of the tumor, and the sensitivity and specificity are both Not high
.

Studies have shown that the sensitivity of CTC to early tumors is 3-10 times that of conventional tumor markers4, and tumors are found 1-4 years earlier than imaging (Table 1)5
.

A study on colorectal cancer showed that the sensitivity of CTC to precancerous lesions can reach 76.
6%6
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The review stated that for the general public, especially high-risk groups, CTC testing can be done on a regular basis in order to detect tumors and treat them early
.

 Tumor patients: Although surgery is a powerful method for tumor treatment, the "clairvoyance" of recurrence monitoring and curative effect monitoring cannot completely remove cancer cells.
Therefore, patients are at risk of recurrence and metastasis after surgery
.

So will the tumor recur in the end? When will it relapse? This requires clinical monitoring
.

Tumor recurrence is the recurrence and development of tumors.
It is a long-term process.
In the early stage, it is more of an increase in tumor cells, which is a microscopic change
.

Traditional monitoring methods (imaging and routine tumor marker examination) have the limitations mentioned above and cannot detect disease recurrence in time
.

CTC detection directly detects tumor cells, and its dynamic results can reflect this microscopic change of tumor cells in the patient's blood, so that recurrence can be monitored, and disease recurrence can be detected earlier than imaging
.

The Chinese Society of Clinical Oncology (CSCO) prostate cancer diagnosis and treatment guidelines also point out that CTC detection can detect tumor micrometastasis or residual disease in the body earlier than imaging, early prediction of prostate cancer patients with high risk of recurrence and metastasis, and regular follow-up monitoring of CTC, which can reflect patients in real time The level of tumor burden in the body helps doctors monitor the condition
.

 At present, for patients receiving anti-tumor drug treatment, the tumor size is generally evaluated by imaging.
This method has a certain lag in the judgment of the tumor status.
It may be that the disease is uncontrollable when abnormal imaging is found
.

A study showed that after drug treatment, the CTC level of patients with remission or stable disease decreased significantly or remained stable, while the CTC level of patients with disease progression increased significantly.
In further follow-up observation, it was also found that CTC was higher than Imaging discovers the progression of the disease 3-6 months earlier
.

Therefore, the decrease in CTC indicates that the tumor treatment effect is good, and the treatment plan can be continued.
The number of CTC rises rapidly, indicating that the tumor is progressing, and the treatment plan and the treatment strategy need to be changed according to the patient's condition
.

CTC detection is almost non-invasive and highly maneuverable.
It can be carried out at any time according to needs.
It can dynamically monitor the CTC level in the patient's blood, monitor the efficacy, detect disease progression early, warn drug resistance, and assist the clinical development of more precise treatment plans
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 In addition, CTC is also a "predictor" of the prognosis of cancer patients.
Studies have shown that patients with high CTC levels before treatment have shorter overall survival, higher risk of recurrence, and worse prognosis.
Therefore, patients with high CTC levels before treatment More intensive follow-up examinations are needed
.

 The folate receptor cell detection (FR+CTC) reagent independently developed by Genuo Bio has been verified by a large number of clinical data and obtained the NMPA Class III registration certificate approved by the State Food and Drug Administration, and won the second prize of the National Science and Technology Progress Award in 2019.
Its clinical validation data was quoted in the "Chinese Expert Consensus on Lung Cancer Screening and Management" issued by the China Lung Cancer Prevention and Treatment Alliance in 2019.
The sensitivity of this technology in detecting early tumors can be as high as 82.
7%9, and it can be used for early tumor detection, prognosis prediction, and recurrence monitoring.
Dynamic monitoring of curative effect can detect disease progression and/or metastasis earlier.
At present, FR+CTC has been used in clinical and scientific research in nearly one hundred tertiary hospitals in China, and has accumulated more than 120,000 tests.
It is an ideal tumor detection and detection technology.

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"Sentinel" Circulating Tumor Cells Allow Early Diagnosis of Lung Cancer in Patients with Chronic Obstructive Pulmonary Disease[J].
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