Achalasia and esophageal cancer: a large database analysis in Japan

Background: Achalasia has been reported to be associated with esophageal cancers (ECs). However, owing to the rarity of achalasia, details of achalasia-related ECs are not well investigated. Method: The incidence of ECs in Japanese patients with achalasia and achalasia-related esophageal motility disorders (EMDs) was estimated, and risk factors for achalasia-related ECs were determined. Characteristics of ECs and treatment courses were also analyzed. Results: Between 2010 and 2019, 2714 Japanese patients with achalasia and achalasia-related EMDs were recorded in 7 high-volume centers; 24 patients (21 men, 3 women) developed ECs. The incidence of ECs was estimated at 0.078 and 0.28 per 100 person-years from the onset and the diagnosis of disease, respectively. Kaplan–Meier estimate suggested that, in addition to a long history of achalasia, advanced age, male sex, and regular alcohol consumption were statistically significant risk factors for EC development. A prevalence of 40 ECs (12.5% multiple lesions, and 22.7% metachronal lesions) was also noted, predominantly distributed over the thoracic esophagus. All were histologically diagnosed as squamous cell carcinoma. Superficial ECs were successfully treated with endoscopic treatment in all cases, except one. Achalasia-related Barret esophagus was extremely rare, and Barret adenocarcinoma was not detected in our cohort. Conclusion: The high relative risk of ECs was clarified in Japanese achalasia patients, although the absolute risk remained low. Therefore, surveillance endoscopy may be recommended in limited patients with several aforementioned risk factors determined. Superficial cancer can be treated with endoscopic treatment. Multiple and metachronal ECs should be screened.