Columnar-lined esophagus measuring less than 1 cm as a risk factor for esophageal squamous cell carcinoma in Japanese men

BACKGROUND AND AIMS: Several case series have noted an association between Barrett's esophagus (BE) and esophageal squamous cell carcinoma (ESCC). We conducted a nationwide retrospective cohort study to examine the association between baseline BE status, particularly ultra-short-segment BE (USSBE; BE <1 cm), and subsequent ESCC development, focusing on the presence or absence of extensive gastric atrophy (GA). METHODS: Consecutive male participants who underwent endoscopy at 17 health check-up institutes in Japan between 2013 and 2017 and had follow-up endoscopy by December 2022 were enrolled. Baseline endoscopic images were reviewed to assess GA and BE status. The primary outcome was ESCC development during follow-up. The association between BE status and ESCC was estimated using the Kaplan-Meier method and Cox regression. RESULTS: Among 20,402 male subjects, 7161 (35.1%) had USSBE. During 116,483.1 person-years of follow-up, 73 cases of ESCC developed. The incidence of ESCC was highest among individuals with USSBE (0.0946%/year). Multivariable analysis revealed that USSBE was independently associated with ESCC (adjusted hazard ratio [HR] 1.82, 95% confidence interval [CI] 1.03-3.24). In exploratory subgroup analyses, USSBE was independently associated with ESCC (adjusted HR 2.40, 95% CI 1.13-5.13) among individuals with extensive GA, while no significant association was observed among those without (adjusted HR 1.34, 95% CI 0.64-2.81; p for interaction = 0.369). CONCLUSIONS: This is the first study to demonstrate a significant association between USSBE and ESCC. USSBE may help identify individuals at increased risk of ESCC. Exploratory subgroup findings according to GA status require further validation.