Endoscopic radiofrequency ablation (RFA) has shown good efficacy and safety in eradicating flat-type early esophageal squamous cell neoplasia (ESCN). However, post-RFA stricture is still a major concern, especially when treating long-segment early ESCNs. The aim of this study was to investigate the efficacy and safety of oral prednisolone to prevent post-RFA stricture.

Esophageal cancer is the eighth most common cancer and the sixth most common cause of cancer death worldwide. The incidence rates of esophageal squamous cancers are still increasing in some countries in the Asia-Pacific region and Africa. Recently, image-enhanced endoscopy techniques such as Lugol or virtual chromoendoscopy have been shown to improve the detection and diagnosis of early esophageal squamous cell neoplasia (ESCN). However, some ESCNs spread laterally and present as long-segment lesions or appear with a mosaic pattern, all of which increase the difficulties and adverse event rates if treated by endoscopic resection. In particular, for extensive ESCNs, endoscopic submucosal dissection (ESD) has been associated with severe refractory stricture, even after pre-emptive steroid administration. This then requires repeated sessions of balloon dilation, leading to a decreased quality of life and increased medical expenses.

Radiofrequency ablation (RFA) has rapidly evolved in recent decades, and previous studies have shown its efficacy and safety in treating early ESCNs. Current evidence has shown that RFA is indicated for totally flat-type precancerous lesions, such as high-grade intraepithelial neoplasia (HGIN) or moderate-grade intraepithelial neoplasia (MGIN), or those that are not feasible for ESD. RFA is less technically demanding and more feasible for widely extended lesions. However, post-RFA esophageal stricture is still a concern, with an average frequency of 14~28%. The longitudinal length of the treatment area is the key factor associated with post-operative stricture. Around 50% of cases where the lesion is extended by more than 9 cm will develop post-RFA esophageal stricture, and thus a preventive strategy is urgently needed. The investigators previously evaluated the in vivo tissue effect of RFA by endoscopic ultrasound, and the results showed that the mucosa and submucosal layer were more edematous and thicker after RFA than before the procedure, suggesting that the thermal effect of RFA may injure the submucosa resulting in inflammation-related fibrosis and stricture. Steroids have an anti-inflammatory effect, and previous studies have shown that steroid treatment could potentially reduce post-ESD stricture in lesions occupying more than three-quarters of the circumference. However, the effectiveness of steroid treatment in preventing post-RFA stricture has yet to be elucidated. Therefore, the aim of this study is to investigate the effectiveness and safety of oral prednisolone treatment in preventing post-RFA esophageal stricture in long-segment and extensive ESCNs.

Inclusion Criteria:

• Histology from endoscopic biopsies showed squamous intraepithelial neoplasia without stromal invasion;
• No lymph node metastasis on endoscopic ultrasound or computed tomography;
• Magnifying endoscopy showed the intraepithelial papillary capillary loop as type B1 pattern, according to the classification of the microvascular architecture of superficial esophageal carcinoma.

Exclusion Criteria:

• A prior history of endoscopic resection, radiation therapy or esophagectomy for esophageal cancer;
• A stricture that prevented the passage of a therapeutic endoscope;
• Uncontrolled coagulopathy;
• Poorly controlled diabetes mellitus.