Non-invasive Testing for the Diagnosis of Early Oesophageal Cancer and Barrett's Dysplasia

The incidence of oesophageal adenocarcinoma has been rising over the last decade. Despite improvements in oncological and surgical therapies the associated survival remains poor, mainly due to delays in diagnosis and advanced stage at presentation. Identifying patients at earlier stages as well as those at risk of cancer may lead to survival benefit. Barrett's oesophagus is an established risk factor for the development of oesophageal adenocarcinoma. It has an established histopathologic progression from low-grade, through high-grade dysplasia (HGD) to oesophageal adenocarcinoma (OAC). Barrett's oesophagus patients currently undergo regular endoscopic surveillance to allow earlier detection of oesophageal cancer.

The primary objective is to evaluate the diagnostic accuracy and clinical utility of the volatile organic compounds (VOC) in exhaled breath to detect early stage oesophageal adenocarcinoma and high-grade dysplastic Barrett's oesophagus.

All patients will be fasted for a minimum of 6 hours prior to the breath sample as part of their routine clinical care. Breath collection will be conducted using a previously validated method. Samples of breath (500ml) collected using "breath collecting device utilising bags". Breath samples collected within thermal desorption tubes (Markes International, Llantrisant, UK) will be transferred to a central laboratory for analysis by gas chromatography mass spectrometry (GC-MS) and proton transfer reaction time of flight mass spectrometry (PTR-ToF-MS). Raw data files will be extracted and analysed in accordance with established protocols.