Response:

Abstract

We appreciate the interest by Tan et al1Tan S. Peng Y. Tang X. Endoscopic surveillance of esophageal cancer before the treatment of achalasia.Gastrointest Endosc. 2020; 92: 457-458Abstract Full Text Full Text PDF Scopus (1) Google Scholar in the American Society for Gastrointestinal Endoscopy guideline on the management of achalasia.2Khashab M.A. Vela M.F. Thosanji N. et al.ASGE guideline on the management of achalasia.Gastrointest Endosc. 2020; 91: 213-227.e6Abstract Full Text Full Text PDF PubMed Scopus (84) Google Scholar In their letter, the authors concluded that given the relative high incidence and poor prognosis of esophageal cancer in patients with achalasia, routine endoscopic surveillance should be performed, especially for patients with more than 10 years of symptom duration. Although the exact mechanism of development of esophageal squamous cell cancer (SCC) in achalasia remains unknown, it is presumed that poor esophageal clearance likely results in stasis inflammation, ultimately leading to the development of dysplasia and esophageal cancer. We agree with the authors that patients with achalasia have a higher incidence of esophageal cancer than the general population, on the basis of cumulative evidence from observational studies.3Gillies C.L. Farrukh A. Abrams K.R. et al.Risk of esophageal cancer in achalasia cardia: a meta-analysis.JGH Open. 2019; 3: 196-200Crossref PubMed Scopus (15) Google Scholar However, there are limited data to support routine screening for the detection of dysplastic lesion or early esophageal cancer in achalasia. There are important considerations before screening or surveillance can be recommended for a specified disease and an at-risk population. To recommend routine endoscopic screening of patients with achalasia, we need unequivocal evidence that routine endoscopic screening is able to identify early-stage esophageal cancer and ultimately reduce mortality from esophageal cancer, and this strategy is cost effective.4Qumseya B. Sultan S. Bain P. et al.ASGE guideline on screening and surveillance of Barrett's esophagus.Gastrointest Endosc. 2019; 90: 335-359.e2Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar It is also important to understand the risk of bias, especially lead-time bias, in published literature that may falsely increase the apparent benefit of screening or surveillance endoscopy. In the current context, lead time will be the interval between a diagnosis of esophageal cancer with screening endoscopy, and the time at which it would have been detected by the onset of clinical symptoms.5Herman C.R. Harmindar K.G. Eng J. et al.Screening for preclinical disease: test and disease characteristics.AJR Am J Roentgenol. 2002; 179: 825-831Crossref PubMed Scopus (78) Google Scholar Without showing survival benefit and increasing life-years in patients undergoing screening endoscopy, it would mean only an increase in detection time for patients with esophageal cancer.4Qumseya B. Sultan S. Bain P. et al.ASGE guideline on screening and surveillance of Barrett's esophagus.Gastrointest Endosc. 2019; 90: 335-359.e2Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar,5Herman C.R. Harmindar K.G. Eng J. et al.Screening for preclinical disease: test and disease characteristics.AJR Am J Roentgenol. 2002; 179: 825-831Crossref PubMed Scopus (78) Google Scholar In addition, endoscopic mucosal evaluation in achalasia patients remains challenging.6Torres-Aguilera M. Remes Troche J.M. Achalasia and esophageal cancer: risks and links.Clin Exp Gastroenterol. 2018; 11: 309-316Crossref PubMed Scopus (15) Google Scholar One population-based study suggested that annual surveillance after the first year would require over 400 endoscopic examinations in men and over 2000 in women to detect 1 case of esophageal SCC.7Sandler R.S. Nyrén O. Ekborn A. et al.The risk of esophageal cancer in patients with achalasia: a population-based study.JAMA. 1995; 274: 1359-1362Crossref PubMed Google Scholar On the basis of these available data, routine screening endoscopy for patients with achalasia will not be cost effective. Previous small case series have shown detection of early-stage esophageal cancer amenable to endoscopic management.8Ota M. Narumiya K. Kudo K. et al.Incidence of esophageal carcinomas after surgery for achalasia: usefulness of long-term and periodic follow-up.Am J Case Rep. 2016; 17: 845-849Crossref PubMed Scopus (11) Google Scholar However, a large prospective long-term study with structured surveillance every 2 to 3 years concluded that the absolute risk for esophageal cancer remains low in patients with longstanding achalasia, and most neoplastic lesions could not be detected on screening until an advanced stage.9Leeuwenburgh I. Scholten P. Alderliesten J. et al.Long-term esophageal cancer risk in patients with primary achalasia: a prospective study.Am J Gastroenterol. 2010; 105: 2144-2149Crossref PubMed Scopus (124) Google Scholar Thus, we believe there is currently insufficient evidence to recommend routine screening endoscopy for esophageal SCC in patients with achalasia. Endoscopic surveillance of esophageal cancer before the treatment of achalasiaGastrointestinal EndoscopyVol. 92Issue 2PreviewWe read the recent guideline by Khashab et al1 with great interest. We appreciate the hard work of the authors, which provides evidence-based recommendations for the management of achalasia in clinical practice. However, we have some suggestions for this guideline. Full-Text PDF