Aldehyde breath test as a disease marker in patients with esophageal and hypopharyngeal squamous cell carcinoma

Abstract Background Patients with inactive aldehyde dehydrogenase 2 (ALDH2) are at high risk for esophageal squamous cell carcinoma (ESCC) and hypopharyngeal squamous cell carcinoma (HPSCC). The aldehyde breath test (ABT) may demonstrate ALDH2 gene polymorphisms. We evaluated the usefulness of the ABT in patients with ESCC and HPSCC. Methods The SCC group consisted of 100 patients who were treated with endoscopic submucosal dissection (ESD) for ESCC or HPSCC, and the control group (HC) consisted of 275 healthy subjects. The SCC group comprised the “single subgroup” (n = 61), in which a single lesion was initially treated with ESD, and the “multiple subgroup” (n = 31), in which multiple lesions were initially treated with ESD. First, we compared the groups’ risk factors for carcinogenesis and measured acetaldehyde-to-ethanol (A/E) ratio. Then we tested the groups’ differences in the abovementioned carcinogenic risk factors. Results We found that the proportion of individuals in the SCC group with inactive ALDH2 (A/E ratio \ge 23.3) was significantly higher than that in the HC group (p = 0.035), as was the A/E ratio (p < 0.001). Also, the proportion of individuals with inactive ALDH2 in the multiple subgroup was significantly higher than that in single subgroup (p = 0.015), as was the A/E ratio (p = 0.008). Conclusions In conclusion, ABT could be a useful tool to identify ESCC and HPSCC and detect multiple or double carcinomas. Trial registration: Trial Registration number: UMIN000040615, Data of Registration: 01 June 2020, retrospectively registered.