Assessment of Tumor Size Before and After Palliative Endoscopic Spray Cryotherapy for Treatment of Dysphagia in Advanced Esophageal Cancer: A Pilot Study

Abstract

Introduction: Endoscopic cryotherapy is increasingly used for the palliation of dysphagia (DP) from bulky esophageal tumors. Our prior research has shown endoscopic cryotherapy to be safe and effective for DP palliation in unresectable esophageal cancer. Although clinical improvements in DP have been documented, there is no evidence to demonstrate objective reduction in tumor size with this treatment modality. The goal of this pilot study was to objectively evaluate the change in the size of the primary esophageal tumor before and after treatment with cryotherapy. Methods: A retrospective consecutive case series of 7 patients with stage IV esophageal adenocarcinoma who received endoscopic cryotherapy for palliation of DP and had contrast enhanced Computerized Tomography (CT) before and after cryotherapy from May 2014 to October 2015. Each mucosal site was treated for 20-30 seconds for 2-3 cycles with at least 45 seconds between freezes to allow complete tissue thawing. Tumor size was assessed using the CT scans. The maximum length and thickness of the tumor was recorded in centimeters (cm). DP was measured using a 4-point Likert scale: 0, no DP; 1, DP to solids; 2, DP to semi-solids; 3, DP to liquids; 4, DP to own saliva. Wilcoxon signed rank test was used to evaluate change in tumor size and DP scores between pre- and post-cryotherapy. Results: Of 7 patients, 6 were males and 1 female. Mean age was 53.3 years. Among 7 patients, a total of 19 cryotherapy treatments were delivered (mean treatments per patient=2.7; range 2-4). All 7 patients also received systemic chemotherapy while undergoing cryotherapy. Six out of 7 patients demonstrated progression of the metastatic disease during this time period. The mean tumor length decreased from 4.4 cm pre-cryo to 3.2 cm post-cryo while the mean tumor thickness decreased from 1.4 cm pre-cryo to 1.2 cm post-cryo. Similarly, the mean DP score improved from 3.5 pre-cryo to 2.5 post-cryo. None of these findings was statistically significant owing to a very small sample size. None of the patients had any adverse effects. Conclusion: Our pilot study provides preliminary evidence of reduction in tumor size following endoscopic cryotherapy for palliation of DP in patients with advanced esophageal cancer. The reduction in tumor size was evident despite progression of distant metastatic disease in the majority of patients. Prospective studies with large sample sizes are needed to confirm this finding.