Multitarget stool DNA test compared with fecal occult blood test for colorectal cancer screening

Serrated Polyp Yield at Colonoscopy in Patients with Positive FIT, Positive mt-sDNA, and Colonoscopy Only: Data from the New Hampshire Colonoscopy Registry

BACKGROUND

Stool-based screening with fecal immunochemical (FIT) or multitarget-stool DNA (mt-sDNA) tests is associated with increased colonoscopy polyp yield. mt-sDNA includes methylated markers, which improve detection of serrated polyps (SP) versus FIT. We compared SP detection in colonoscopies performed for positive FIT or mt-sDNA tests, as well as in colonoscopies without a preceding stool test, using the New Hampshire Colonoscopy Registry, a comprehensive statewide population-based registry.

METHODS

Across the three groups, we compared the frequency of clinically relevant SPs (CRSP: sessile SPs, hyperplastic polyps ≥10 mm, and traditional serrated adenomas). We also compared SP size, histology, number, and bulk (combined sizes).

RESULTS

Our sample included 560 mt-sDNA+ (age ± SD: 66.5 ± 7.9), 414 FIT+ (age ± SD: 66.3 ± 8.8), and 59,438 colonoscopy-only patients (age ± SD: 61.7 ± 8.0). mt-sDNA+ patients were more likely to have a higher yield of CRSPs and CRSP bulk than FIT+ (P < 0.0001) or colonoscopy-only patients (P < 0.0001). More mt-sDNA+ patients had CRSPs without large adenomas or colorectal cancers (17.9% vs. 9.9% of FIT+ and 8% of colonoscopy-only patients). After adjusting for synchronous large adenomas, colorectal cancers, and other risk factors, mt-sDNA+ patients were more likely (OR, 1.82; 95% CI, 1.18-2.85) than FIT+ patients to have CRSPs.

CONCLUSIONS

mt-sDNA+ patients had a higher SP yield than FIT+ or colonoscopy-only patients, particularly in the absence of synchronous large adenomas or colorectal cancer.

IMPACT

Our results suggest that screening with mt-sDNA tests could improve colorectal cancer screening by identifying more patients at increased risk from the serrated pathway.

Diagnostic accuracy of the multi-target stool DNA test in detecting colorectal cancer: A hospital-based study

BACKGROUND

The multi-target stool DNA test (MT-sDNA) has potential utility in the detection of colorectal cancer (CRC), but validation of its clinical accuracy has been limited in China.

AIM

To evaluate the diagnostic performance of MT-sDNA and investigate the combined diagnostic value of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and carbohydrate antigen 199 (CA199) with MT-sDNA in CRC and adenomas.

METHODS

We evaluated the performance of the MT-sDNA kit based on a hospital clinical trial. In this case-control study, 135 participants from the Affiliated Hospital of Medical School of Ningbo University, including 51 CRC patients, 23 patients with adenomas, and 61 healthy controls were enrolled. We used a risk scoring system to determine the positivity of tests with histological diagnosis or colonoscopy as the reference standard.

RESULTS

The main indices of sensitivity, specificity and accuracy were evaluated. The sensitivity and specificity for CRC detection were 90.2% and 83.3%, respectively, with an accuracy of 89.8%. For adenoma, the sensitivity and specificity were 56.5% and 68.9%, respectively, with an accuracy of 73.1%. The sensitivity and specificity of MT-sDNA combined with CEA in the diagnosis of adenoma were 78.3% and 60.7%, respectively.

CONCLUSION

The MT-sDNA test showed better performance in the detection of CRC, which was superior to AFP, CEA, and CA199 separately, but not for predicting adenomas. The combination of MT-sDNA with CEA further improved the sensitivity for adenoma diagnosis.

Fecal biomarkers: Non-invasive diagnosis of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world in terms of morbidity and mortality, which brings great health hazards and economic burdens to patients and society. A fecal examination is an effective method for clinical examination and the most commonly used method for the census. It is simple, non-invasive, and suitable for large-scale population screening. With the development of molecular biology, lots of efforts have been made to discover new fecal biomarkers for the early screening of colorectal cancer. In this review, we summarize and discuss the recent advances of fecal biomarkers for CRC screening or diagnosis, including DNA biomarkers, RNA biomarkers, protein biomarkers, gut microbes and volatile organic compounds focusing on their diagnostic evaluation for CRC, which can provide a basis for the further development of new and effective CRC fecal screening and early diagnosis techniques.

Colonoscopy Findings in FIT+ and mt-sDNA+ Patients versus in Colonoscopy-only Patients: New Hampshire Colonoscopy Registry Data

Few studies compare fecal immunochemical test (FIT) and multi-target stool DNA (mt-sDNA) outcomes in practice. We compared colonoscopy yield following FIT+ or mt-sDNA+ tests to colonoscopies without preceding stool tests in the comprehensive population-based New Hampshire Colonoscopy Registry (NHCR). Outcomes were any neoplasia and an ordered outcome: adenocarcinoma, advanced neoplasia (adenoma/serrated polyp ≥ 1 cm/villous/high-grade dysplasia), nonadvanced neoplasia, or normal. Our total sample included 306 mt-sDNA+ (average age ± SD 67.0 ± 7.9), 276 FIT+ (66.6 ± 8.7), and 50,990 colonoscopy-only patients (61.8 ± 8.1). Among average-risk patients (N = 240 mt-sDNA+, N = 194 FIT+, N = 26,221 colonoscopy only), mt-sDNA+ patients had a higher risk for any neoplasia (67.1%) compared with FIT+ (54.6%, P = 0.00098) or colonoscopy (40.8%, P < 0.0001). Severity of findings and histology subtypes differed across the three groups (P < 0.0001 for both), with a higher yield of advanced findings in mt-sDNA+ patients. In particular, clinically relevant serrated polyps (hyperplastic polyps ≥10 mm/traditional serrated adenomas/sessile serrated polyps) were detected at a higher frequency in mt-sDNA+ patients as compared with FIT+ or colonoscopy-only patients. Even after adjustment, patients with positive mt-sDNA [OR = 2.82; 95% confidence interval (CI), 2.00-4.02] or FIT+ tests (OR = 1.67; 95% CI, 1.19-2.36) were more likely to have histologically more advanced findings than colonoscopy alone. At follow-up colonoscopy, mt-sDNA+ tests were more likely to predict neoplasia than FIT+, largely due to increased detection of serrated polyps. Prevention Relevance: Colorectal cancer screening options include colonoscopy and stool-based tests, including the fecal immunochemical test (FIT) and the multi-target stool DNA (mt-sDNA) test which, if positive, must be followed by a colonoscopy. Assessing "real-world" outcomes of colonoscopies following positive stool tests can inform their clinical use. See related Spotlight, p. 417.

Technical considerations in PCR-based assay design for diagnostic DNA methylation cancer biomarkers

Background

DNA methylation biomarkers for early detection, risk stratification and treatment response in cancer have been of great interest over the past decades. Nevertheless, clinical implementation of these biomarkers is limited, as only < 1% of the identified biomarkers is translated into a clinical or commercial setting. Technical factors such as a suboptimal genomic location of the assay and inefficient primer or probe design have been emphasized as important pitfalls in biomarker research. Here, we use eleven diagnostic DNA methylation biomarkers for colorectal cancer (ALX4, APC, CDKN2A, MGMT, MLH1, NDRG4, SDC2, SFRP1, SFRP2, TFPI1 and VIM), previously described in a systematic literature search, to evaluate these pitfalls.

Results

To assess the genomic assay location, the optimal genomic locations according to TCGA data were extracted and compared to the genomic locations used in the published assays for all eleven biomarkers. In addition, all primers and probes were technically evaluated according to several criteria, based on literature and expert opinion. Both assay location and assay design quality varied widely among studies.

Conclusions

Large variation in both assay location and design hinders the development of future DNA methylation biomarkers as well as inter-study comparability.

Promising Epigenetic Biomarkers for the Early Detection of Colorectal Cancer: A Systematic Review

In CRC, screening compliance is decreased due to the experienced discomfort associated with colonoscopy, although this method is the gold standard in terms of sensitivity and specificity. Promoter DNA methylation (hypomethylation or hypermethylation) has been linked to all CRC stages. Study objectives: to systematically review the current knowledge on approved biomarkers, reveal new potential ones, and inspect tactics that can improve performance. This research was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines; the risk of bias was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies criteria (QUADAS-2). The Web of Science® Core Collection, MEDLINE® and Scopus® databases were searched for original articles published in peer-reviewed journals with the specific keywords "colorectal cancer", "early detection", "early-stage colorectal cancer", "epigenetics", "biomarkers", "DNA methylation biomarkers", "stool or blood or tissue or biopsy", "NDRG4", "BMP3", "SEPT9", and "SDC2". Based on eligibility criteria, 74 articles were accepted for analysis. mSDC2 and mSEPT9 were frequently assessed in studies, alone or together as part of the ColoDefense panel test-the latter with the greatest performance. mBMP3 may not be an appropriate marker for detecting CRC. A panel of five methylated binding sites of the CTCF gene holds the promise for early-stage specific detection of CRC. CRC screening compliance and accuracy can be enhanced by employing a stool mt-DNA methylation test.