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Potential Impact of Updated Bayesian Deduction in Medicine: Application to Colonoscopy Prioritization
1
ITISB, Facultad de Ingeniería, Universidad Andres Bello, Viña del Mar, Chile 2520000, Chile
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Unidad de Coloproctología. Servicio de Cirugía. Complejo Asistencial Doctor Sotero del Rio. Santiago 8550000, Chile
3
Centro para la Prevención y Control del Cáncer (CECAN), Viña del Mar 2520000, Chile
*
Author to whom correspondence should be addressed.
Cancers 2025, 17(23), 3845; https://doi.org/10.3390/cancers17233845 (registering DOI)
Submission received: 16 September 2025
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Revised: 14 October 2025
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Accepted: 15 October 2025
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Published: 29 November 2025
(This article belongs to the Special Issue Recent Advances in Diagnosis and Management of Colorectal Cancer)
Simple Summary
Traditional single-test strategies using faecal immunochemical tests (FIT) for the detection of colorectal cancer can often yield uncertain results, leading to unnecessary colonoscopies or missed diagnoses. In this paper, we show how when applied to four consecutive FITs, Updated Bayesian Deduction (UBD) indicates that colonoscopies were unnecessary for over 85% of symptomatic patients and over 98% of asymptomatic patients. This approach also dynamically stratifies patient risk. UBD could also use other indicators to better assess cancer probability. This approach represents an important step towards explainable, evidence-based precision medicine. In Chile, for example, where waiting times for colonoscopies for symptomatic patients in public hospitals can exceed one year, this method could prioritise those with the highest likelihood of advanced neoplasia, thereby reducing delays for critical cases and potentially saving lives.
Abstract
Background/Objectives: This study presents and explores the potential of Updated Bayesian Deduction (UBD) using colorectal cancer (CRC) detection and prioritisation as a case example. Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide, and its prognosis strongly depends on early detection and timely treatment. In Chile, colonoscopy waiting lists for symptomatic patients in public hospitals can exceed one year, limiting access to early diagnosis and reducing survival rates. Traditional single-test screening strategies, such as a single faecal immunochemical test (FIT), often yield uncertain results, contributing to inefficiencies in resource allocation. Methods: We propose a new approach that integrates evidence from multiple sequential and independent FITs to dynamically update the posterior probability of CRC. A case study is analysed with this Updated Bayesian Deduction over a four-round FIT protocol to assess how this could improve risk stratification compared to standard symptoms-based screening. Results: Our mathematical model shows that over 85% of colonoscopies for symptomatic patients were not urgent. We then demonstrate that, if 4-FIT UBD were used to screen Chile’s Metropolitan Region population, only 96 out of 100,000 people would require an urgent colonoscopy to detect the 19.6 out of 100,000 individuals with CRC in this region. Many countries cannot afford a colonoscopy-based population screening, such as what is performed in Germany. Performing 4x FITs + a very small number of colonoscopies would be much more affordable and would get more countries to adopt general CRC screening. Conclusions: In countries with limited colonoscopy availability, such as Chile, where symptomatic patients can wait over a year for treatment in public hospitals, implementing a UBD-based strategy could drastically reduce costs and optimise the use of resources. This would improve access to colonoscopies for critical cases and ultimately enhance five-year survival rates. These findings highlight UBD as a promising approach for evidence-based precision medicine in CRC screening and prioritisation that is both explainable and adaptable.
