Randomised control trial of surveillance and no surveillance for patients with Barrett's oesophagus - BOSS (Barrett's Oesophagus Surveillance Study)

Cancer of the gullet (oesophageal adenocarcinoma) is the fastest rising cancer in the developed world. Thirty years ago it was a rare malignancy and now there are over 5,000 cases each year in the UK. The most accepted sequence of events is that longstanding stomach acid reflux induces a cancerous change in the lining of the gullet (oesophagus) in susceptible individuals. The change in the cells is termed Barrett's oesophagus. The UK has the highest incidence of oesophageal adenocarcinoma worldwide. In advanced cancer, the prognosis is poor: half of the patients will die within a year. This concern has promoted the development of surveillance programs. Guidelines recommend that patients with Barrett's oesophagus have an endoscopy every 2-3 years to detect changes early when the prognosis is much more favourable. These guidelines acknowledge that the data to support surveillance in patients with Barrett's oesophagus using endoscopy are relatively weak, and the value of surveillance is still subject to considerable debate. There are some observational data to suggest that patients enrolled in surveillance programmes have oesophageal cancer detected at an earlier stage than non surveillance detected cancers and have a better survival. These are very weak data in epidemiological terms. A randomised controlled trial is needed. Surveillance by endoscopy for Barrett's oesophagus is expensive, it commonly causes minor adverse events (1-10%) and 10% of patients reported that it is inconvenient. It causes anxiety and very rarely can result in complications of oesophageal perforation or death (0.03% and 0.001% respectively). It is important to establish the efficacy and cost effectiveness of such an intervention before routinely offering it to patients.