In this prospective single center study, up to 25 patients with Barrett's esophagus with LGD or no dysplasia (Group 1), 25 patients with HGD/IMCA (Group 2), 25 patients with esophageal carcinoma confined to the esophageal wall (Group 3) and 25 patients with severe esophageal squamous dysplasia (Group 4) will be treated with endoscopic cryotherapy. This study is single arm and no blinding will be utilized. Interim analysis of the data will be reviewed with a DCI statistician after 14 patients in each group have been treated with cryotherapy and if safety and efficacy is documented to that point in time, we will request the ability to extend the enrollment to a maximum allowable amount of 25 patients per group. The proposed study duration is seven years, allowing two years for patient enrollment and 5 years for post treatment follow-up. Study duration per patient will total approximately six years.
Patients with Barrett's esophagus with no dysplasia or low grade dysplasia (group 1) will be treated with cryotherapy at six week intervals until Barrett's mucosa is ablated or six treatments are administered. Patients with Barrett's HGD and IMCA or severe esophageal squamous dysplasia (groups 2 and 4) will be treated with cryotherapy at six-week intervals until Barrett's mucosa is ablated or six treatments are administered. More advanced mass lesions are typically more difficult to eradicate with ablative therapies and may progress faster than patients with IMCA, therefore, patients with more advanced cancer (group 3) will be treated every 2 weeks until the lesion is eradicated up to eight treatments.
After cryotherapy treatment is complete (i.e. the esophagus has re-epithelialized with normal squamous epithelium for Groups 1, 2, 4 and the tumor is locally controlled/absent in Group 3), patients will be assessed by endoscopy and biopsy every three months for one year, every six months for two years, then annually for two years (flow sheet - appendix 1; study schedule - appendix 2).