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As an extracellular DNA existing in plasma, serum, cerebrospinal fluid or other body fluids, circulating tumor DNA (ctDNA) stems mainly from necrotic or apoptotic tumor cells, exosome secreted from tumor cells, and circulating tumor cells; and usually measures 160-180 bp. ctDNA is a type of cell-free DNA (cfDNA) and makes up a small proportion (0.1%-1%). Therefore, it is difficult to detect ctDNA. The maturity of next generation sequencing (NGS) technique improves the sensitivity and accuracy of ctDNA test, accelerates application of ctDNA detection to clinical purposes, helps doctors with individualized diagnosis & treatment, and brings enormous convenience to the treatment of cancer patients.

In a ctDNA test featuring non-invasive and individualized diagnosis and treatment, peripheral blood is taken to obtain ctDNA for sequencing; and gene variation status related to anti-cancer drug is analyzed. This leads to comprehensive and correct reading of the correlation between anti-cancer drug and gene; and facilitates doctors in setting personalized medication solutions. 

Features of ctDNA test

1) Convenient sampling: non-invasive, multiple times in real time, easy access

For a ctDNA test, drawing blood is the only step to complete analysis and reading of cancer cell DNA. Invasive methods such as puncture and surgery are rendered unnecessary, therefore freeing patients from the risk and pain of cancer tissue collection. At the early stage of malignant cancer, ctDNA content and abnormal gene change can be detected. ctDNA test can achieve real-time, multi-phase and individualized services of diagnosis and treatment.

2) Mature detecting technique: great sensitivity, high degree of accuracy, and low false positive rate

NGS-based detection of ctDNA is sensitive and accurate, and can help detect low-frequency mutation as low as 0.1%. In a study published on New England Journal of Medicine, Dawson and other scholars pointed out that ctDNA was more sensitive and reflected tumor progression and treatment effect at an earlier stage than other tumor markers.

ctDNA carries the gene information of cancer patients. Quantitative or qualitative analysis of ctDNA is of significant clinical value to the early diagnosis, treatment, condition monitoring, and prognosis evaluation for cancer patients. With the capacity to present comprehensive molecular biological characteristics, ctDNA test is an ideal tumor marker.

3) Comprehensive test: wide scope of application

Almost all cancer cells can release DNA segments to blood. Therefore, ctDNA can reflect the general status of tumor in patient’s body. Clinically, ctDNA can be applied to A) early diagnosis of tumor; B) monitoring of tumor evolution and adaptation change; C) real-time monitoring of the effect of drugs; and tracking of tumor lapse, metastasis and recurrence; D) personalized treatment plan. Heterogeneity has large effect on tumor tissue gene test. However, ctDNA test avoids random and localized sampling because of tumor tissue heterogeneity, thus making tumor mutation test result more comprehensive and reliable.

Test technique

1) Target area capture

2) High-throughput sequencing


Content of the test

Scope of the test

1) Comprehensive test of 247 key genes related to cancer.

2) Accurate reading of the correlations between 195 anti-tumor drugs and genes.

Period of the test

Starting from the day when the laboratory receives the sample, the test report is issued within 15 working days.

Sample type

10ml whole blood

Sample collection



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