Urinary Volatile Organic Compound Testing in Fast-Track Patients with Suspected Colorectal Cancer

Area of Science:

• Biochemistry
• Analytical Chemistry
• Oncology

Background:

• Colorectal symptoms are common, but serious pathology like colorectal cancer (CRC) is infrequent.
• Current diagnostic methods for CRC often involve invasive procedures, leading to unnecessary testing for reassurance.

Purpose of the Study:

• To investigate the feasibility of urinary volatile organic compound (VOC) testing as a triage tool for patients undergoing assessment for possible CRC.
• To evaluate the diagnostic accuracy of VOC analysis in differentiating between CRC, adenomatous polyps, and controls.

Main Methods:

• A prospective, multi-center observational study involving 558 patients referred to NHS fast-track pathways for potential CRC.
• Urine samples were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS), Field Asymmetric Ion Mobility Spectrometry (FAIMS), and Selected Ion Flow Tube Mass Spectrometry (SIFT-MS).
• An artificial neural network (ANN) model was used to analyze VOC data, correlating results with colonoscopy and CT colonography findings.

Main Results:

• Urinary VOC testing was found to be feasible, acceptable to patients, and applicable within the clinical fast-track pathway.
• GC-MS analysis demonstrated high clinical utility for detecting CRC and polyps (sensitivity = 0.878, specificity = 0.882, AUROC = 0.896), although it is labor-intensive.
• Clinically significant differences in VOC profiles were observed between patients with cancer, polyps, and those with no pathology.

Conclusions:

• Urinary VOC testing is a feasible and acceptable method within NHS fast-track CRC pathways.
• VOC analysis, particularly using GC-MS, shows potential as a non-invasive triage tool for early detection of colorectal cancer and polyps.
• Further development of VOC analysis could significantly aid in the diagnostic workup of patients with suspected colorectal cancer.