Breath test helps identify colorectal cancer
A non-invasive breath test that measures exhaled volatile organic compounds may help in the diagnosis of colorectal cancer and advanced adenomas, according to results of a multicenter study.
Kelly E. van Keulen, of the department of gastroenterology and hepatology at Radboud University Medical Center, and colleagues wrote that analyzing volatile organic compounds (VOCs) is a newer technique in the world of colorectal cancer but is already showing some promise.
“Some potential CRC-associated VOCs have already been identified in small pilot studies, but the VOCs identified differed among studies and (external) validation of the results is lacking,” they wrote. “Data on VOCs associated with colorectal polyps is even more scarce.”
Researchers conducted a multicenter study comprising 511 adults scheduled to undergo a colonoscopy. Patients also submitted breath tests using Aeonose devices (The eNose Company). Researchers randomly assigned two-thirds of the breath tests to develop training models, which they used to predict the diagnosis of the remaining patients.
Investigators excluded 64 patients from their analysis due to inadequate breath tests, incomplete colonoscopy or colitis, and grouped the remaining results based on the most advanced lesion found during colonoscopy; CRC (n = 70), advanced adenoma (n = 117), non-advanced adenoma (n = 117), hyperplastic polyp (n =15) and normal colonoscopy (n = 125).
The training models for CRC and advanced adenomas had an area under the curve of 0.76 and 0.71, respectively, and blind validation returned AUCs of 0.74 and 0.61. The final model for CRC had an AUC of 0.84 (95% sensitivity, 64% specificity), while the final advanced adenoma model had an AUC for 0.73 (79% sensitivity, 59% specificity).
“Future studies in the field of VOC analysis should focus on standardizing all phases of VOC analysis among different gas analysis techniques to obtain a translatable approach for future VOC research,” van Keulen and colleagues wrote. “Large scale studies are required to evaluate the influence of covariates on VOC profiles (eg, co-morbidities, medication use, lifestyle factors) and to explore the full diagnostic potential of VOC analysis, preferably with external validation.” – by Alex Young
Disclosure: The authors report no relevant financial disclosures.