Non-invasive breath testing to detect colorectal cancer: protocol for a multicentre, case-control development and...

Area of Science:

• Oncology
• Respiratory Medicine
• Analytical Chemistry

Background:

• Colorectal cancer (CRC) is a leading cause of cancer death in the UK, with survival rates dramatically lower for late-stage diagnosis.
• Non-specific symptoms of CRC often delay diagnosis, making early detection crucial.
• Breath analysis offers a potential non-invasive method for detecting CRC-specific volatile organic compounds (VOCs).

Purpose of the Study:

• To develop and validate a clinical prediction model (CPM) for colorectal cancer detection using a breath test.
• To explore the potential of combining breath analysis with faecal immunochemical testing (FIT) for improved diagnostic accuracy.
• To assess the clinical utility of decision rules derived from the CPM for patient triage.

Main Methods:

• A multicentre, case-control study (COBRA2) involving 720 participants (250 CRC, 470 controls).
• Breath samples collected from participants undergoing colonoscopy or with confirmed CRC, analyzed via gas chromatography-mass spectrometry.
• Statistical and machine learning methods used to develop the CPM, with validation in an independent cohort.

Main Results:

• Exploratory analysis of VOCs to identify CRC-specific markers.
• Development of a CPM based on breath test results.
• Assessment of whether incorporating FIT data enhances the CPM's diagnostic performance.

Conclusions:

• The non-invasive breath test has the potential for earlier and more accurate CRC detection.
• This approach may improve patient acceptability and facilitate timely secondary care referral.
• Successful validation could lead to improved curative treatment and survival rates for CRC patients.