Next-generation Multi-target Stool DNA Panel Accurately Detects Colorectal Cancer and Advanced Precancerous Lesions.

The multi-target stool DNA (mt-sDNA) test screens for colorectal cancer by analyzing DNA methylation/mutation and hemoglobin markers to algorithmically derive a qualitative result. A new panel of highly discriminant candidate methylated DNA markers (MDM) was recently developed. Performance of the novel MDM panel, with hemoglobin, was evaluated in a simulated screening population using archived stool samples weighted to early-stage colorectal cancer and prospectively collected advanced precancerous lesions (APL). Marker selection study (MSS) and separate preliminary independent verification studies (VS) were conducted utilizing samples from multi-center, case-control studies. Sample processing included targeted MDM capture, bisulfite conversion, and MDM quantitation. Fecal hemoglobin was quantified using ELISA. Samples were stratified into 75%/25% training-testing sets; model outcomes were cross-validated 1,000 times. All laboratory operators were blinded. The MSS included 232 cases (120 colorectal cancer/112 APLs) and 490 controls. The VS featured 210 cases (112 colorectal cancer/98 APLs) and 567 controls; APLs were 86.7% adenomas and 13.3% sessile serrated lesions (SSL). Average age was 65.5 (cases) and 63.2 (controls) years. Mean sensitivity in the VS from cross-validation was 95.2% for colorectal cancer and 57.2% for APLs, with specificities of 89.8% (no CRC/APLs) and 92.4% (no neoplasia). Subgroup analyses showed colorectal cancer sensitivities of 93.4% (stage I) and 94.2% (stage II). APL sensitivity was 82.9% for high-grade dysplasia, 73.4% for villous lesions, 49.8% for tubular lesions, and 30.2% for SSLs. These data support high sensitivity and specificity for a next-generation mt-sDNA test panel. Further evaluation of assay performance will be characterized in a prospective, multi-center clinical validation study (NCT04144738). PREVENTION RELEVANCE: This study highlights performance of the next-generation mt-sDNA test, which exhibits high sensitivity and specificity for detecting colorectal cancer and APLs. This noninvasive option has potential to increase screening participation and clinical outcomes. A multi-center, clinical validation trial is underway. See related commentary by Bresalier, p. 93.

Clinical performance of an automated stool DNA assay for detection of colorectal neoplasia.

BACKGROUND & AIMS: Colorectal cancer (CRC) and advanced precancers can be detected noninvasively by analyses of exfoliated DNA markers and hemoglobin in stool. Practical and cost-effective application of a stool DNA-based (sDNA) test for general CRC screening requires high levels of accuracy and high-capacity throughput. We optimized an automated sDNA assay and evaluated its clinical performance. METHODS: In a blinded, multicenter, case-control study, we collected stools from 459 asymptomatic patients before screening or surveillance colonoscopies and from 544 referred patients. Cases included CRC (n = 93), advanced adenoma (AA) (n = 84), or sessile serrated adenoma ≥1 cm (SSA) (n = 30); controls included nonadvanced polyps (n = 155) or no colonic lesions (n = 641). Samples were analyzed by using an automated multi-target sDNA assay to measure ß-actin (a marker of total human DNA), mutant KRAS, aberrantly methylated BMP3 and NDRG4, and fecal hemoglobin. Data were analyzed by a logistic algorithm to categorize patients as positive or negative for advanced colorectal neoplasia (CRC, advanced adenoma, and/or SSA ≥1 cm). RESULTS: At 90% specificity, sDNA analysis identified individuals with CRC with 98% sensitivity. Its sensitivity for stage I cancer was 95%, for stage II cancer it was 100%, for stage III cancer it was 96%, for stage IV cancer it was 100%, and for stages I-III cancers it was 97% (nonsignificant P value). Its sensitivity for advanced precancers (AA and SSA) ≥1 cm was 57%, for >2 cm it was 73%, and for >3 cm it was 83%. The assay detected AA with high-grade dysplasia with 83% sensitivity. CONCLUSIONS: We developed an automated, multi-target sDNA assay that detects CRC and premalignant lesions with levels of accuracy previously demonstrated with a manual process. This automated high-throughput system could be a widely accessible noninvasive approach to general CRC screening.