China develops new method of early screening for colorectal cancer

Professor Xu Ruihua's team collected circulating tumor DNA (ctDNA) extracted from plasma in 801 patients with colorectal cancer and 1,021 normal controls, and screened nine methylated markers that could be used to diagnose colorectal cancer, as well as five methylated markers that could be used to predict the prognosis of colorectal cancercirculating tumor DNA is a small fragment of the genome released into the circulatory system by tumor cells, a characteristic tumor biomarker, like a "fingerprint" left by tumor cellsthis study shows that the accuracy of colorectal cancer diagnostic models based on circulating tumor DNA methylation markers is 96%, while the accuracy of the current clinically commonly used colorectal cancer serum marker cancer antigen CEA is only 67%In addition, the accuracy of the new prognosis model for patient survival prediction is significantly higher than that of the current clinically commonly used prognostic indicators, which means that doctors can use it to treat different patients with colorectal cancer with more personalized and precise treatmentresearchers also conducted both colonoscopy screening and circulating tumor DNA methylation markers in 1,493 patients at high risk of colorectal cancer, which showed that the sensitivity of the latter to detect early bowel cancer was as high as 89.7 percent, and the sensitivity of progressive adenomas (precancerous lesions) was 33.3 percent, and better patient compliance, providing a new noninvasive method for early screening of colorectal cancer.