Volatile organic compounds for the detection of hepatocellular carcinoma—A scoping review

Hepatocellular carcinoma (HCC) is an increasingly common and the second leading cause of cancer mortality worldwide with a 5-year survival rate about 12%. Less than 20% of HCC patients are eligible to curative treatment owing to the late presentation. Clearly, there is a need for a readily accessible, early screening tool. This scoping review critically appraises and synthesizes the current published knowledge about the use of exhaled volatile organic compounds (VOCs) as a potential noninvasive means for HCC detection aiming to advance this nascent field. A systematic electronic search was conducted. The search strategy included all studies published until the 24th of March 2023 using a combination of relevant keywords. The search yielded 9 publications using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Two of the studies described in vitro experiments, and seven clinical studies were conducted on small groups of patients. Overall, 42 headspace gases were analyzed in the in vitro studies. Combined, the clinical studies included 420 HCC patients and 630 controls. The studies reported potential role for a combination of VOCs in the diagnosis of HCC. However, there is lack of consensus. Although there appears to be promise in VOCs research associated with HCC, there is no single volatile biomarker in exhaled breath attributed to HCC and data from extracted studies indicates a lack of standardization. Large multicentre population studies are required to verify the existence of VOCs linked to HCC.