Spray cryotherapy versus continued radiofrequency ablation in persistent Barrett's esophagus

Applications of cryotherapy in premalignant and malignant esophageal disease: Preventing, treating, palliating disease and enhancing immunogenicity?

Cryotherapy is a treatment modality that uses extreme cold to destroy unwanted tissue through both immediate and delayed cellular injury. This therapy is increasingly being adopted across various medical specialties due to its minimally invasive nature and technological advancements that have been made. In the esophagus, cryotherapy is particularly utilized for the management of Barrett esophagus. It has been demonstrated to be effective and safe with potential benefits, such as a reduction in pain, over radiofrequency ablation. Additionally, it might offer a valuable alternative for patients unresponsive to radiofrequency ablation. Cryotherapy is applied for other conditions as well, including esophageal squamous cell neoplasia and malignant dysphagia. More research is needed to gain understanding of the utility in these conditions. Interestingly, cryotherapy has shown the ability to enhance the host’s immune response in reaction to antigens left in situ after treatment. While preclinical data have demonstrated promising results, the immune response is often insufficient to induce tumor regression in the clinical setting. Therefore, there is growing interest in the combination of cryotherapy and immunotherapy where ablation creates an antigen depot, and the immune system is subsequently stimulated. This combination holds promise for the future and potentially opens new doors for a breakthrough in cancer treatment.

Efficacy and Safety of Cryoablation in Barrett's Esophagus and Comparison with Radiofrequency Ablation: A Meta-Analysis

BACKGROUND

The mainstay approach in endoscopic eradication therapy (EET) for dysplastic Barrett's esophagus (BE) includes the endoscopic resection of visible lesions, accompanied by ablation of the residual metaplastic epithelium. Cryoablation therapy is one such emerging ablation technique in this field. This systematic review with a meta-analysis aims to accumulate pooled data on cryoablation performance in the treatment of patients with BE and to compare this technique to the standard of care radiofrequency ablation (RFA).

METHODS

The MEDLINE, Cochrane, and Scopus databases were searched until June 2024 for studies evaluating BE management using cryoablation for cumulative results. The primary outcome was the complete eradication of dysplasia (CED) and intestinal metaplasia (CEIM) in BE compared to RFA, while secondary outcomes included the respective pooled rates using cryoablation, recurrence, and adverse events, with a separate analysis for strictures. The meta-analyses were based on a random-effects model, and the results were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Subgroup analyses by type of cryoablation were also performed.

RESULTS

Twenty-three studies (1604 patients) were finally included, four of which were comparative. CED and CEIM did not differ significantly between cryoablation and RFA [OR= 0.95 (95%CI: 0.50-1.81) and OR = 0.57 (95%CI: 0.20-1.63), respectively)]. The pooled rates of CED, CEIM, and recurrence after cryoablation were 84.2% (95%CI: 79.1-89.3), 64.1% (95%CI: 49.2-79.0), and 8.3% (95%CI: 4.7-11.9), accompanied by high rates of heterogeneity. Adverse events were noted in 14.5% (95%CI: 9.9-19.2) of cases, and 6.5% (95%CI: 4.1-9.0) developed strictures. In the subgroup analysis, the cryoballoon achieved a reduction in heterogeneity in CED, adverse events, and stricture formation, whereas spray catheters provided homogenous results in terms of recurrence.

CONCLUSIONS

Cryoablation provides equal outcomes compared to RFA in the treatment of patients with BE, with the cryoballoon achieving relatively homogenous rates of CED and adverse events.

Molecular Biology and Clinical Management of Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) is a highly lethal malignancy. Due to its rising incidence, EAC has become a severe health challenge in Western countries. Current treatment strategies are mainly chosen based on disease stage and clinical features, whereas the biological background is hardly considered. In this study, we performed a comprehensive review of existing studies and discussed how etiology, genetics and epigenetic characteristics, together with the tumor microenvironment, contribute to the malignant behavior and dismal prognosis of EAC. During the development of EAC, several intestinal-type proteins and signaling cascades are induced. The anti-inflammatory and immunosuppressive microenvironment is associated with poor survival. The accumulation of somatic mutations at the early phase and chromosomal structural rearrangements at relatively later time points contribute to the dynamic and heterogeneous genetic landscape of EAC. EAC is also characterized by frequent DNA methylation and dysregulation of microRNAs. We summarize the findings of dysregulations of specific cytokines, chemokines and immune cells in the tumor microenvironment and conclude that DNA methylation and microRNAs vary with each different phase of BE, LGD, HGD, early EAC and invasive EAC. Furthermore, we discuss the suitability of the currently employed therapies in the clinic and possible new therapies in the future. The development of targeted and immune therapies has been hampered by the heterogeneous genetic characteristics of EAC. In view of this, the up-to-date knowledge revealed by this work is absolutely important for future EAC studies and the discovery of new therapeutics.