Recommendations for a step‐wise comparative approach to the evaluation of new screening tests for colorectal cancer

Abstract

BACKGROUNDNew screening tests for colorectal cancer continue to emerge, but the evidence needed to justify their adoption in screening programs remains uncertain.METHODSA review of the literature and a consensus approach by experts was undertaken to provide practical guidance on how to compare new screening tests with proven screening tests.RESULTSFindings and recommendations from the review included the following: Adoption of a new screening test requires evidence of effectiveness relative to a proven comparator test. Clinical accuracy supported by programmatic population evaluation in the screening context on an intention‐to‐screen basis, including acceptability, is essential. Cancer‐specific mortality is not essential as an endpoint provided that the mortality benefit of the comparator has been demonstrated and that the biologic basis of detection is similar. Effectiveness of the guaiac‐based fecal occult blood test provides the minimum standard to be achieved by a new test. A 4‐phase evaluation is recommended. An initial retrospective evaluation in cancer cases and controls (Phase 1) is followed by a prospective evaluation of performance across the continuum of neoplastic lesions (Phase 2). Phase 3 follows the demonstration of adequate accuracy in these 2 prescreening phases and addresses programmatic outcomes at 1 screening round on an intention‐to‐screen basis. Phase 4 involves more comprehensive evaluation of ongoing screening over multiple rounds. Key information is provided from the following parameters: the test positivity rate in a screening population, the true‐positive and false‐positive rates, and the number needed to colonoscope to detect a target lesion.CONCLUSIONSNew screening tests can be evaluated efficiently by this stepwise comparative approach. Cancer 2016;122:826–39. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Diagnostic test evaluation methodology: A systematic review of methods employed to evaluate diagnostic tests in the absence of gold standard – An update

“…With this approach, the medical test is assessed based on what it is designed to do [191]. Other designs include case-control designs (where the participants are known to have or not have the target condition) [207, 208], laboratory based studies or experimental studies which are undertaken with the aim to evaluate the analytical sensitivity and specificity of the index test [190, 209, 210].…”

Strategies for Colorectal Cancer Screening

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In�vivo and in�vitro induction of the apoptotic effects of oxysophoridine on colorectal cancer cells via the Bcl‑2/Bax/caspase-3 signaling pathway

“…Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies worldwide ( 1 , 2 ). In previous years, with the improvement of living conditions, increases in lifespan and alterations to environmental pollution factors, the morbidity and mortality of colorectal cancer has increased significantly, alongside a decrease in the age of disease onset ( 3 – 5 ).…”