Esophageal squamous cell carcinoma arising after endoscopic ablation therapy of Barrett's esophagus with high-grade dysplasia. Report of a case

Genetic Insights in Barrett's Esophagus and Esophageal Adenocarcinoma

Beginning in the 1980s, an alarming rise in the incidence of esophageal adenocarcinoma (EA) led to screening of patients with reflux to detect Barrett's esophagus (BE) and surveillance of BE to detect early EA. This strategy, based on linear progression disease models, resulted in selective detection of BE that does not progress to EA over a lifetime (overdiagnosis) and missed BE that rapidly progresses to EA (underdiagnosis). Here we review the historical thought processes that resulted in this undesired outcome and the transformation in our understanding of genetic and evolutionary principles governing neoplastic progression that has come from application of modern genomic technologies to cancers and their precursors. This new synthesis provides improved strategies for prevention and early detection of EA by addressing the environmental and mutational processes that can determine "windows of opportunity" in time to detect rapidly progressing BE and distinguish it from slowly or nonprogressing BE.

Limitations of endoscopic ablation in Barrett's esophagus

In the last 5-10 years, endoscopic ablative therapies have been gaining ground as treatment for Barrett's esophagus associated with high-grade dysplasia and early cancer, and they are becoming the most preferred technique over surgery as the standard of care. These therapies are associated with a lower rate of complications and mortality than surgery; studies have found them to be safe, effective and tolerable. Endoscopic ablative therapies are not, however, without their drawbacks. There is a paucity of data on long-term efficacy, and direct comparisons of the different modalities are lacking. Unlike surgery, current data suggest that endoscopic ablation treatments may not be curative in all patients, so patients require ongoing surveillance and acid suppression. Questions remain regarding durability as well as factors promoting recurrence after endoscopic therapy. The authors conducted a systematic review of the literature on ablative therapies in Barrett's esophagus to describe the modalities currently available and to provide an understanding of their limitations.

Squamous cell carcinoma after radiofrequency ablation for Barrett's dysplasia

Barrett's oesophagus (BO) is a usually indolent condition that occasionally requires endoscopic therapy. Radiofrequency ablation (RFA) is an effective endoscopic treatment for high grade dysplasia (HGD) and intramucosal cancer in BO. It has a good efficacy, durability and safety profile although complications can occur. Here we describe a case of RFA in a patient with high grade dysplasia. Although the response to treatment was initially very good with the development of neosquamous epithelium, the patient very rapidly developed a squamous cell cancer of the oesophagus confirmed on radiology, histology and immunohistochemistry. Sanger sequencing confirmed that the original HGD and the squamous cell cancer (SCC) were derived from separate clonal origins. The report highlights the fact that SCC of the oesophagus has been noted after endoscopic ablation for BO previously and suggest that ablation of BO may encourage the clonal expansion of cells carrying carcinogenic mutations once a dominant clonal population has been eradicated.

Update on ablation for Barrett's esophagus

Endoscopic ablation has dramatically changed the treatment algorithm for patients with Barrett's esophagus. Studies clearly show the benefits of this approach for patients with high-grade dysplasia and intramucosal carcinoma. Recent studies also provide evidence in support of this approach for patients with low-grade dysplasia but not for patients with nondysplastic Barrett's epithelium. Endoscopic ablation is safe and efficacious in most but not all patients and disease progression may occur during initial therapy as well as after successful completion in a small difficult to identify subset of patients. Furthermore, the past year has provided us with a better understanding of the durability of endoscopic ablation with highly variable rates of disease recurrence. Studies are underway to help determine predictors of response and recurrence.