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Background: Stool DNA test has been emerged as an effective noninvasive method for colorectal cancer (CRC) screening, but the real‐world performance of stool DNA test in Chinese population has rarely been reported. Methods: A total of 36,527 subjects were recruited in Haining City from January 2021 to December 2021. Participants underwent primary screening by taking both two‐samples fecal immunochemical tests (FITs) and high‐risk factor questionnaire (HRFQ), and those who tested either positive by FITs or evaluated to be high risk by HRFQ were recommended to undertake subsequent stool DNA test and colonoscopy. Results: Of 36,527 participants, 34,778 (95%) completed both HRFQ and FITs, 9947 (29%) showed positive results during primary screening, and the colonoscopy compliance rate was 49%. Of primary screening positives, 8733 (88%) completed stool sample collections, and colonoscopy results from 4293 eligible participants were used for analyzing the performance of stool DNA test. The sensitivities for detecting CRC and advanced adenomas (AA) were 100% (95% CI: 60–100%) and 40% (95% CI: 34–46%), and the area under curve (AUC) was 0.961 (95% CI:0.954–0.967) and 0.625 (95% CI: 0.609–0.641), respectively. The specificity of stool DNA test was 84% (95% CI: 82–85%). The false‐positive rate for stool DNA test is about 10% less than that of primary screening. Conclusion: Stool DNA test is a cost‐effective and promising alternative strategy for CRC screening in China. [ABSTRACT FROM AUTHOR]

Background. Colorectal cancer (CRC) is one of the leading causes of cancer deaths worldwide and in China. Early CRC screening is the best approach to reduce its incidence and mortality rates. The ColoDefense test, a multiplex qPCR assay simultaneously detecting both methylated SEPT9 and SDC2 genes, has demonstrated improved clinical performance on either methylation biomarker alone for CRC screening with both blood and stool samples. Method. Leftover blood chemistry test samples from 125 CRC, 35 advanced adenoma, and 35 small polyp patients and 92 healthy control subjects were examined by the ColoDefense test. Among these samples, the levels of three circulating tumor markers, CEA, AFP, and CA19-9, were also measured for 106 CRC, 28 advanced adenoma, and 20 small polyp patients and all control subjects. Results. Due to the smaller volume and extended storage in nonfrozen state, the ColoDefense test with these samples exhibited reduced performance for all stages of CRC and advanced adenomas. The performance of CEA, AFP, and CA19-9 and their various combinations was also evaluated for CRC screening to identify the tumor marker combinations with the best performance. When combined with the ColoDefense test, the identified combinations did improve the clinical performance. Conclusion. These results suggested a rational path towards developing a CRC screening method that takes advantage of leftover blood chemistry test samples. The successful development of such a method will undoubtedly help promote early CRC screening by increasing its accessibility for the general public. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) has become the second leading cause of new cancer cases and the fifth of cancer deaths in China, and early detection is the most effective way to reduce the incidence and mortality of CRC. A number of methylated DNA biomarkers have been found to associate with CRC and precancerous lesions in stool samples, indicating stool methylated DNA biomarkers are potential tools for CRC early detection. In this study, approximately 5 g of stool specimen was collected from 230 subjects (124 in the training set and 106 in the validation set). Stool DNA was extracted and bisulfite-converted, followed by ColoDefense test, a multiplex qPCR assay, that simultaneously detects methylated SEPT9 (m SEPT9) and methylated SDC2 (m SDC2). Youden index was employed to determine the cut-off value of ColoDefense test for stool specimens. In the training set, the optimized cut-off value of stool ColoDefense test was: m SEPT9 analyzed with 3/3 algorithm and mean m SEPT9 Ct values of <38, or m SDC2 with 2/3 algorithm. Stool ColoDefense test achieved Youden indexes of 79.9 and 57.4% in detecting CRC and advanced adenomas (AA), respectively. Its sensitivities in the training set for AA and CRC were 66.7% (95% CI: 24.1–94.0%) and 89.1% (95% CI: 77.1–95.5%) with a 90.8% (95% CI: 80.3–96.2%) specificity, and AUC was 0.956 (95% CI: 0.924–0.988). In the validation set, its sensitivities for AA and CRC were 66.7% (95% CI: 24.1–94.0%) and 92.3% (95% CI: 78.0–98.0%) with a 93.2% (95% CI: 82.7–97.8%) specificity, and AUC was 0.977 (95% CI: 0.952–1.000). Positive detection rate of stool ColoDefense test has been found to be independent of age, gender, tumor location, and tumor size. In conclusion, stool ColoDefense test demonstrated high sensitivities and specificity for the detection of AA and CRC. Therefore, it has the potential to become a low-cost, convenient, and highly effective tool for CRC early detection. [ABSTRACT FROM AUTHOR]

Gastric cancer (GC) is a leading cause of cancer death and an important barrier to increasing life expectancy in China. Early detection of GC can significantly reduce its mortality rate. A new plasma-based multiplex DNA methylation assay combining simultaneous detection of three biomarkers (KCNQ5 , C9orf50 and CLIP4) and one control gene (ACTB) was developed. It was used to examine 12 paired tissue samples and a training cohort of 151 plasma samples. Its performance was subsequently confirmed in validation cohort 1 (n = 105) and validation cohort 2 (n = 139). Three methylation markers showed significantly higher methylation levels in GC tissues than in paired adjacent tissues. The assay showed a sensitivity of 67.9 % with a specificity of 86.6 % for GC detection in the training cohort, and the AUC was 0.786 (95 % CI: 0.701–0.855). The methylation levels in GC patients were significantly higher than those in benign gastric tumors and in control group. Meanwhile, the assay achieved a sensitivity of 65.5 % with a specificity of 90.0 % in the validation cohort 1, and the AUC was 0.805 (95 % CI: 0.716–0.876). In the validation cohort 2, its sensitivity and specificity were 73.7 % and 84.1 %, respectively, and the AUC was 0.851 (95 % CI: 0.776–0.909). The plasma-based multiplex DNA methylation assay was highly specific for GC early detection. It has the potential to become an alternative approach to improve diagnosis of GC in the clinics. [ABSTRACT FROM AUTHOR]