Summary
Introduction: Between 1 and 6% of population present Barrett´s esophagus disease. The progress to intestinal metaplasia and dysplasia, and its potential malignization to esophageal cancer is the major concern. The annual risk has been estimated in between 0.5 and 1% for intestinal metaplasia, and it grows to 59% after 5 years from diagnosis of high-grade dysplasia. The 5-year overall survival of adenocarcinoma is 38% for local disease, 20% for regional disease and only 3% for disseminated cancer. In Spain, the esophageal cancer mortality rate was 3,86/ 100 000 inhabitants in 2013. The mortality rate increases with age until 14,94 (75-79 years). Esophagectomy is being replaced by endoscopic techniques as treatment of high grade dysplasia and intramucosal cancer. Radiofrequency ablation of the tissue is one of these techniques, that generates heat to ablate the affected tissue.
Objective: To evaluate efficacy, effectiveness and safety of radiofrequency ablation (with or without endoscopic mucosal resection) as a treatment technique in Barrett´s esophagus with high grade dysplasia or intramucosal cancer.
Methods: A preliminary research to identify systematic reviews was conducted. One systematic review of high quality was included and updated. Its research strategy stopped in october 2013. A new research was done until February 2015 in Medline (Pubmed), EMBASE (Ovid), ISI Web of Science (Web of Knowledge, Wok), Cochrane and HTA agencies databases. Data were summarized in evidence tables and the quality of the studies was assessed using the scale from the Oxford Centre for Evidence Based Medicine and the Quality Appraisal Tool for Case Series (Institute of Health Economics, IHE; Alberta Canada) and the bias risk tool for randomized clinical trials from The Cochrane Collaboration. In the results, the means and standard deviations weighted by sample size were calculated with the SPSS statistics programme (version 19).
Results: 20 studies were included in the analysis. There were 11 studies from the systematic review and 9 studies from the update. There are only 3 randomized clinical trials with small sample sizes,(and one of them is a follow-up study). The other studies are observational (8 prospective series and 9 retrospective series). Quality of the studies was variable. The follow-up periods were different and the results presentation were very inconstant. Complete eradication of displasia is 85% and complete eradication of intestinal metaplasia is lower, (72%). The recurrence of dysplasia was 5,1% and the recurrence of metaplasia was 11,8%. Time to recurrences was 265 days and 529 days respectively.
Cancer progression happened in 46 patients (3%). Regarding the safety, strictures are the principal complication and it occurs in the 6% of the patients. It requires treatment with dilation (from 1 to 8). Bleeding and mucosal damage follows strictures with 0,93% and 0,62% respectively. The only death occurred to a patient who required oesophagectomy due to progression to invasive cancer and died intraoperatively.
Conclusions: Radiofrequency ablation of the Barrett´s oesophagus with high-grade dysplasia and intramucosal carcinoma appears to be effective and safe. However there is not enough high quality evidence. Larger studies with adequate comparators are needed.