Diagnostic Ability of Volatile Organic Compounds in Digestive Cancer: A Systematic Review With Meta-Analysis

Abstract

Background: Volatile organic compounds (VOCs) have been involved in cancer diagnosis via breath, urine, and feces. We aimed to assess the diagnostic ability of VOCs on digestive cancers. Methods: We systematically reviewed prospective clinical trials evaluating VOCs’ diagnostic ability on esophageal, gastric, colorectal, hepatic, and pancreatic cancer (PC). Databases including PubMed and Ovid-Medline were searched. Results: A total of 35 trials with 5314 patient-times qualified for inclusion. The pooled sensitivity of VOCs diagnosing gastroesophageal cancer from healthy controls is 0.89 (95% confidence interval [CI]: 0.82-0.94), the pooled specificity is 0.890 (95% CI: 0.84-0.93), and area under the curve (AUC) of the summary receiver operating characteristic curve is 0.95 (95% CI: 0.93-0.95). The pooled sensitivity of VOCs diagnosing colorectal cancer from heathy controls is 0.92 (95% CI: 0.85-0.96), the pooled specificity is 0.88 (95% CI: 0.77-0.94), and the AUC is 0.96 (95% CI: 0.94-0.97). The pooled sensitivity of VOCs distinguishing gastrointestinal (GI) cancer from precancerous lesions is 0.84 (95% CI: 0.67-0.92), the pooled specificity is 0.74 (95% CI: 0.43-0.91), and the AUC is 0.87 (95% CI: 0.84-0.89). The pooled sensitivity of VOCs diagnosing hepatocellular carcinoma is 0.68 (95% CI: 0.52-0.81), the pooled specificity is 0.81 (95% CI: 0.47-0.96), and the AUC is 0.78 (95% CI: 0.74-0.81). The pooled sensitivity of VOCs diagnosing PC is 0.88 (95% CI: 0.80-0.93), the pooled specificity is 0.82 (95% CI: 0.62-0.93), and the AUC is 0.92 (95% CI: 0.89-0.94). Conclusions: Volatile organic compounds have potential role in diagnosing GI cancer with comparatively high sensitivity, specificity, and AUC (PROSPERO registration number: CRD42021260039).

Breath Volatile Organic Compounds in Surveillance of Gastric Cancer Patients following Radical Surgical Management

“…The breath VOC diagnostic principle has been demonstrated to be very attractive for many cancers, including GC [31][32][33]; however, there is very limited information published so far on the potential use of VOC detection for cancer surveillance. According to our knowledge, this is the first study having addressed the role of VOCs in GC.…”

C. elegans as a Powerful Tool for Cancer Screening

“…Therefore, a routine pancreatic cancer screening test, sensitive at an early stage, is needed. Differences exist among cancers in the human volatilome in the urine [ 45 , 67 , 68 , 69 ]. We hypothesized that knocking out in AWC olfactory neurons of C. elegans , a specific GPCR may lead to a chemotactic response specific to a single cancer type using a urine sample.…”

Towards detection of cancer biomarkers in human exhaled air by transfer-learning-powered analysis of odor-evoked calcium activity in rat olfactory bulb

“…Certain volatile organic compounds (VOCs) can serve as biomarkers of GC. Noninvasive screening method for digestive cancer can be based on detecting such VOCs in exhaled breath of patients [ [4] , [5] , [6] , [7] ]. This is because the volatile compounds (or their pattern) in cancer cells differ from those in healthy tissues.…”