For the first time, endoscopists have used focal cryoballoon ablation to eradicate early esophageal squamous cell neoplasias, including high-grade lesions in treatment-experienced patients.
A single session of treatment with the novel, portable nitrous oxide system (C2 Therapeutics, Redwood City, Calif.) produced complete pathologic and endoscopic responses at 3 months in 8 of 10 patients, reported Marcia Irene Canto, MD, of Johns Hopkins University in Baltimore, with her associates. Two to five sessions produced complete responses in the other two patients, and all patients were disease-free at their last visit (median follow-up, 10.7 months; interquartile range, 4-14 months). The study was published online July 15 in Gastrointestinal Endoscopy (2017. doi: 10.1016/j.gie.2017.07.013).
©Nephron/Wikimedia Commons/CC BY-SA 3.0/No changes
Standard treatments for esophageal squamous cell neoplasia have drawbacks. Submucosal dissection can cause bleeding, perforation, and stenosis, and radiofrequency ablation (RFA) is associated with stricture. To test an alternative, the researchers used a portable, hand-held, battery-powered cryoballoon ablation system that successfully eradicated Barrett’s esophagus lesions in two prior studies. The machine contains liquid nitrous oxide, which turns to gas when released into a balloon catheter in the endoscope. The gas inflates the balloon, enabling the endoscopist to see through it to the neoplastic mucosa, which is pretreated with Lugol chromoendoscopy. The endoscopist then cryoablates the target lesion across the balloon wall. Unlike cryospray, the entire dose of cryogen hits the lesion, the investigators noted. Also, the gas is automatically evacuated without the need for suctioning or decompression, and the treatment process does not require heavy gas tanks or repeated freeze-thaw cycles.
In this study, all 10 patients achieved complete endoscopic and pathologic responses at 3 months. Seven patients were followed for 1 year, and none showed biopsy evidence of neoplastic progression. In contrast, a prospective trial of circumferential radiofrequency ablation without endoscopic mucosal resection or endoscopic submucosal dissection reported a 12-month rate of complete response of 84%, the researchers noted (Endoscopy. 2015;47:398-408). There were no serious treatment-related adverse events. Pain was usually self-limited, although one patient required 2 days of narcotics. Two patients developed symptomatic strictures 6-8 weeks after treatment that resolved with balloon dilation. Both of these patients had undergone extensive multifocal ablation. “Circumferential treatment of ESCN [esophageal squamous cell neoplasia] remains problematic for all endoscopic ablative therapies, with a high stricture rate of 20% in our small pilot study of cryoablation and 20%-23% with RFA,” the investigators wrote. “The risk for postablation stricture appears to be related to a long length of ESCN. Optimizing the cryogen dose, technique, and decrease in Lugol’s solution concentration might alter the incidence of postablation strictures for ablative treatments.”
Study participants were 55-90 years old, and six were female. Four were treatment naive, and six had progressed despite endoscopic mucosal resection, RFA, spray cryotherapy, argon plasma coagulation, or multiple therapies. Seven patients had high-grade lesions, two had low-grade lesions, and one had early esophageal squamous cell carcinoma. Most lesions were distally located, but two were in the middle esophagus and one was proximal. The largest lesion measured 4 cm and the maximum length of all lesions in a single patient was 10 cm. Patients did not have visible esophageal masses or evidence of advanced or metastatic disease.
“Comparative effectiveness trials might eventually determine the role of cryoablation in the treatment of early ESCN,” the researchers concluded. An open-label, nonrandomized clinical trial of the balloon cryotherapy device is underway in China (NCT02605759). The article did not list funding sources or disclosures.