Positive 100% predicts whether the cancer will come back! A new milestone in ct DNA detection!

As an important method for early cancer screening, liquid biopsy is undoubtedly a hot research field in recent years. Liquid biopsy is different from the detection of solid tumor tissue, the gold standard currently used for tumor diagnosis in clinical practice. Liquid biopsy mainly detects tumor-related substances in the blood to confirm the occurrence and development of tumors. Currently, the main liquid biopsies used are circulating tumor DNA (that is, the protagonist ct DNA this time) and circulating tumor cells (CTC).

If a tumor wants to metastasize, it needs to release cancer cells to travel around in the blood, looking for a suitable site for metastasis, which releases circulating tumor cells. Although tumor cells will continue to replicate, but the immune cells of the human body are not vegetarian, many tumor cells will be killed by immune cells, and then release the genetic material - ct DNA.

In fact, ctDNA will be released as long as the tumor cells are damaged or dead, whether it is just after tumor occurrence, treatment or after treatment. Therefore, ctDNA can play a certain role in tumor prediction, treatment effect tracking, and prognosis detection. It is recommended to take a look at this article we wrote before:

Collection | What is the clinical role of ctDNA detection?

However, as an emerging technology, ctDNA still has a long way to go to full clinical use. In order to allow ct DNA to better enter the clinic, scientists from all over the world are constantly researching and updating ct DNA technology to seek better diagnostic results.

Just recently, a study was published in the journal "Clinical Cancer Research" under the AACR, a top international medical research organization. This is the first study that did not use tumor tissue detection and all used ct DNA as a follow-up detection method. The results found that the positive predictive value of ct DNA for recurrence monitoring results reached 100%!

Although many patients receive radical surgery for cancer, tiny residual cancer lesions are likely to bury the root cause of cancer recurrence - so ctDNA has also been used for recurrence detection in previous studies, but they are all related to tumor tissue sequencing Combined, the possible changes in the tumor can be further estimated and tracked.

But this time, the researchers decided to test the capabilities of the ctDNA technology alone. Unlike previous ctDNA assays, the new ctDNA assay developed by the researchers this time integrates both genomic and epigenetic-related cancer signatures. The tumor can be tracked without detecting the tumor tissue - in the clinic, there are many patients whose tumor tissue may not be available, so ctDNA technology can play a good monitoring role.

In this experiment, the researchers included a total of 103 colorectal cancer patients who underwent radical surgery, and a total of 252 blood samples were extracted for analysis. Of the 103 patients, a total of 84 were evaluable after treatment, including those who had undergone surgery and completed adjuvant chemotherapy. The researchers tracked the patients' plasma levels 1 month after treatment and overall status 1 year later. The results showed:

In 15 patients with subsequent detection of ct DAN, the follow-up results showed that 15 patients eventually developed recurrence, and the positive predictive value (PPV) reached 100%!

At the critical time node, 49 patients with undetectable ctDNA expression eventually relapsed in 12 patients;

If continuous longitudinal monitoring is combined with blood samples drawn within 4 months, the sensitivity can be increased from 69% to 91%;

The data show that the integration of epigenetic related information can improve the overall sensitivity by 25% to 36% compared with the results of the pure genome!

This is the result of the first studies, and further advances are needed to confirm the accuracy and validity of the new ctDNA technology. In fact, human research on early cancer screening has been advancing. Compared with treatment, early detection and diagnosis of cancer can greatly improve the survival rate of cancer patients and reduce the treatment burden of patients. It is believed that with the development of ctDNA diagnostic technology, more cancer patients will benefit from it.