Diagnostic Performance of Multitarget Stool DNA and CT Colonography for Noninvasive Colorectal Cancer Screening

Abstract

O ptical colonoscopy remains the dominant strategy for colorectal cancer (CRC) screening in the United States and is used for both cancer prevention and detection. However, optical colonoscopy is an invasive and resourceintense primary screening examination. Less invasive CRC screening tests provide an alternative, complementary option for population-based screening; patients with positive results are referred for optical colonoscopy as the de facto therapeutic standard. However, these noninvasive tests may differ in their ability to prevent CRC through the detection of advanced precancerous polyps. Available noninvasive screening examinations that are approved by the U.S. Food and Drug Administration include stool-based tests and CT colonography. Vast previous screening experiences with fecal occult blood and immunochemical testing have been published previously (1), but the data for multitarget stool DNA (mt-sDNA) and CT colonography screening are limited, and these tests were only recently included in the U.S. Preventive Services Task Force guidelines (2). Data are just now emerging on the postapproval clinical screening experience with the Cologuard (Exact Sciences, Madison, Wis) mt-sDNA test (3-5). Nonetheless, nationwide use of this stool-based test has dramatically increased since its simultaneous approval was granted in August 2014 by the U.S. Food and Drug Administration and the Centers for Medicare and Medicaid Services. Since then, millions of screening tests have been performed. Published data on CT colonography screening are mainly limited to trial data and clinical practice at a single center (6-9). Clinical validation trials (8-10) can derive the sensitivity and specificity of these noninvasive tests for key outcomes such as advanced neoplasia and CRC because every patient undergoes the reference standard, optical colonoscopy. However, in actual clinical practice, diagnostic evaluation

Novel Diagnostic Biomarkers in Colorectal Cancer

“…Overall detection rates for advanced neoplastic lesions were significantly greater with CT colonography screening (5.0%) than with the mt-sDNA test (2.7%). Overall detection rates for CRC were 0.31% and 0.23%, respectively [ 342 ].…”

Radiomics features based on internal and marginal areas of the tumor for the preoperative prediction of microsatellite instability status in colorectal cancer

“…Accordingly, in our study, the maximum cross-section of the lesion was delineated, and the adduction technique was used to analyze radiomics features from different intratumoral regions. The short diameters of the included tumors were > 1 cm, which not only optimize the clinical efficacy ( 45 ), but also avoid image annihilation during processing. The tumor margin was retracted by 1–3 mm respectively, and seven radiomics models were generated.…”

Optimal Strategies for Colorectal Cancer Screening

“…The benefits of mt-sDNA are that it can be performed in non-clinical settings, does not require diet or medication restrictions, can be performed every 3 years, and is non-invasive with low potential for adverse effects [4,18]. Additionally, there may be increased sensitivity for right-sided colon lesions that are more often missed with other non-colonoscopic screening methods [19].…”

“…The benefits of CT colonography are that it is less invasive than colonoscopy, does not require sedation or anesthesia, has a low complication rate, and is relatively safe for individuals with medical comorbidities that preclude traditional colonoscopy [3,24]. Compared to mt-sDNA, CT colonography detects more advanced adenomas and has a higher positive predictive value [18]. Unlike stool-based screening tests, it often allows for same-day endoscopic evaluation if needed [18].…”