ABSTRACT
Introduction: At the onset of the COVID-19 pandemic, all patients undergoing endoscopic surveillance for Barrett's Oesophagus (BE) in the UK were indefinitely postponed. As well as the potential for missed progression to dysplasia, the negative impact on patients' quality of life is immeasurable. The Cytosponge® is a minimally invasive cell sampling device which has been researched in screening for BE. We describe the first worldwide use of the Cytosponge® outside of a clinical trial to support the triage of BE patients unable to undergo endoscopic surveillance due to COVID-19. Aims and Methods: Consecutive patients with non-dysplastic BE (NDBE) or those deemed to be low risk after previous treatment for BErelated dysplasia, DBE (more than 18 months after completion of therapy with no visible BE and no intestinal metaplasia/dysplasia at last endoscopy) with no prior history of stenosis who were overdue endoscopy (OGD) were invited to have the Cytosponge®. The sample was analysed for TFF3 (a marker of intestinal metaplasia), cellular atypia and p53. Fisher's test was used to examine the association between the overall cytosponge result and its individual components with follow-up OGD outcomes. Results: To date, 153 patients (mean age 66 years, 126 male) have undergone the Cytosponge® procedure. The median maximal length of BE was 3cm (1-15cm). Three patients were unable to swallow the device and 19 (12%) needed a repeat procedure as no columnar cells were present suggesting that the sponge had not entered the stomach. 87 patients (80%) with NDBE had a either a low-risk result (TFF3 positive only – 62) or required a repeat Cytosponge® routinely (TFF3/atypia/ p53 negative – 25). The remaining 21 patients (20%) needed an OGD within 3 months, 17 of which have since had an OGD. Of these 17 patients, 4 had a new diagnosis of dysplasia (indefinite - 2, low grade dysplasia – 1, intramucosal cancer - 1) and 2 a new diagnosis of cancer. 18/87 patients in the low-risk NDBE cohort have undergone follow-up OGD (NDBE 17/18, high grade dysplasia 1/18). Of the 23 patients in the post-treatment BE cohort, 1 patient had a high-risk result and subsequent OGD confirmed HGD (Table 1). A high-risk cytosponge result and the presence of both p53 and typia were all associated with a positive OGD result. Over-expression of p53 appeared to be the most sensitive marker (Table 2). In treatment naive patients, a low-risk cytosponge result was closely associated with no dysplasia detected at follow-up OGD with a negative predictive value of 94%. Conclusions: Cytosponge® has proved to be a useful non-endoscopic tool for patients with BE under surveillance where OGD is not possible. Preliminary data are promising to help triage patients and may in turn offer a less invasive approach to monitoring patients compared to endoscopy, particuarly for low risk patients. (Table Presented) (Table Presented)
ABSTRACT
Introduction The CytospongeTM test is a non-endoscopic method to collect cells from the oesophagus and test for biomarkers of early oesophageal cancer and its precancerous form, Barrett's oesophagus. The real-world implementation pilots of the Cytosponge has been accelerated in response to the COVID-19 pandemic. At the onset of the pandemic, when endoscopy services were paused, guidelines from the British Society of Gastroenterology were updated to recommend the use of alternatives including the Cytosponge. In December 2020, NICE published a Medtech Innovation Briefing for use of the Cytosponge test as a triage tool for endoscopy to identify people at risk of oesophageal cancer. Aims & methods Implementation pilots were launched within the NHS in England and Scotland, as well as the Innovate UK-funded research project, Project DELTA. The Cytosponge test was offered to two patient cohorts as an alternative to endoscopy: (1) patients already diagnosed with Barrett's Oesophagus, and so in need of routine surveillance;and (2) patients referred from primary care with reflux symptoms. Samples were received, processed and analysed at the ISO 15189:2012 accredited laboratory at Cyted. Pathology reports were issued with TFF3, p53 and atypia biomarker results and clinical recommendations. Any reports positive for p53/atypia biomarkers were double reported. Here, we evaluate the real-world laboratory metrics for the Cytosponge test in secondary care. Results Between August 2020 and November 2021, Cytosponge tests were delivered to 5373 patients at 48 hospitals across England and Scotland. For 4842 diagnostic reports issued by mid-November, 2807 patients had Barrett's Oesophagus and 2034 reflux symptoms. For Barrett's surveillance, 2629 (93.7%) of patient samples had sufficient cellular material for analysis, including sampling the gastric cardia. Of these 324 (12.3%) exhibited cellular atypia (including uncertain significance), dysplasia, or aberrant p53 expression. These patients were recommended to have an endoscopy. Patients without evidence of atypia/dysplasia/p53 were recommended surveillance by Cytosponge or endoscopy after the recommended interval by clinical guidelines. In the symptomatic reflux cohort, 1854 (91.2%) patient samples had sufficient cellular material for analysis, including sampling the gastric cardia. Of these 185 (10.0%) exhibited intestinal metaplasia corroborated by TFF3 expression and a further 44 (2.4%) exhibited atypia/ dysplasia/p53. These patients were recommended to have an endoscopy. Otherwise, patients were recommended management according to symptoms. Discussion A high-quality centralised laboratory service has enabled accelerated real-world implementation of the Cytosponge in the secondary care setting. This has enabled triage and care of patients who have not been able to access endoscopy during the COVID-19 pandemic.