S924 Esophageal Myotomy Is Associated With Reduced Esophageal Cancer and Mortality in Achalasia: A Real-World Cohort Study

Introduction: Patients with achalasia have an increased risk of esophageal cancers, such as squamous cell carcinoma. Although peroral endoscopic myotomy (POEM) or Heller’s myotomy can reduce dysphagia symptoms, less is known about their impact on esophageal cancer. Methods: This retrospective cohort study used the TriNetX database to identify adults (≥18 years) with achalasia. Patients were grouped into those who underwent myotomy (POEM or Heller) and those who did not. Individuals with prior Barrett’s esophagus, esophagectomy, or esophageal cancer were excluded. The primary outcome was incident esophageal cancer, with subgroup analysis by histologic subtype. Secondary outcome was all-cause mortality. Propensity score matching balanced baseline characteristics. Cox proportional hazards modeling and adjusted odds ratios (aORs) assessed associations, adjusting for demographics, comorbidities, and medication exposures. Results: A total of 8,106 patients underwent myotomy and 53,874 did not. Median follow-up was 609 days (interquartile range (IQR): 1,746) for the myotomy group and 896 days (IQR: 1,961) for the non-myotomy group. After matching, baseline characteristics were balanced. Myotomy was associated with a significantly lower risk of esophageal cancer (before matching: 6 vs 202; aOR: 0.323; 95% confidence interval [CI] 0.171-0.610, after: 6 vs 24; aOR: 0.417; 95% CI 0.199-0.871). Subgroup analysis showed no significant differences in squamous cell carcinoma (before: 4 vs 37; aOR: 1.769; 95% CI 0.879-3.559, after: 4 vs 6; aOR: 1.00; 95% CI 0.416-2.404) or adenocarcinoma (before: 4 vs 82; aOR: 0.797; 95% CI 0.413-1.538, after: 4 vs 11; aOR: 0.909; 95% CI 0.386-2.142). Myotomy was also linked to reduced all-cause mortality before (330 vs 6,496, adjusted hazard ratio [aHR]: 0.235; 95% CI 0.196-0.281) and after matching (330 vs 705; aHR: 0.445; 95% CI 0.389-0.509). Cox regression identified male sex (aHR: 2.64; 95% CI 1.97-3.53), older age (aHR per year: 1.03; 95% CI 1.02-1.04), and alcohol use (aHR: 3.10; 95% CI 1.39-6.90) as independent predictors of esophageal cancer. Gastroesophageal reflux disease, tobacco, obesity, and proton pump inhibitor use were not significant. Conclusion: In short-term follow-up, myotomy in achalasia was associated with lower risks of esophageal cancer and mortality compared to non-myotomy care. Subgroup analysis by histology showed no significant difference, likely due to low event rates. Prospective studies with longer follow-up are needed to confirm these findings and clarify the oncologic impact of achalasia treatment.