P4 Clinical and endoscopic characteristics associated with interval upper gastrointestinal cancers: a systematic review and meta-analysis

Introduction The prognosis of upper gastrointestinal (UGI) cancers generally is very poor and attributed to advanced stage at diagnosis. Approximately one in every twelve patients with an UGI cancer in the UK receives a gastroscopy within three years prior to diagnosis (an interval cancer). This systematic review aimed to (1) determine the clinical and endoscopic characteristics associated with interval UGI cancers (compared with incident cancers), and (2) quantify the proportion of individual endoscopic findings in endoscopies within three years preceding diagnosis of interval cancer. Methods We searched MEDLINE and Embase from Jan 1, 2000, to Feb 7, 2020, for studies comparing the characteristics of interval and incident UGI cancers, and studies reporting the proportion of findings at the initial ‘cancer-negative’ endoscopy in those with interval cancer. We synthesised results using random effects meta-analysis. This review is registered on PROSPERO, CRD42019125780. Results A total of 997 citations were screened and 13 studies were included in the meta-analysis, comprising 44315 UGI malignancies, of which 5067 (11.4%) were interval cancers. In studies reporting the interval between the first ‘cancer-negative’ endoscopy and diagnosis of cancer (within 3 years), the median interval was 18 months. There were no significant differences in age or gender between interval and incident UGI cancers. Patients with interval cancers were less likely to present with dysphagia (OR 0.38, 95% CI 0.17–0.88) or weight loss (OR 0.50, 95% CI 0.28–0.92). There were no differences in presentation with anaemia (OR 0.62, 95% CI 0.23–1.64), GI bleeding (OR 1.20, 95% CI 0.75–1.91), or vomiting (OR 0.69, 95% CI 0.36–1.30). Gastro-oesophageal reflux (OR 2.69, 95% CI 2.28–3.18) was associated with a higher odds of interval malignancy. Endoscopist experience was not associated with interval cancers (OR 1.16, 95% CI 0.79–1.69). Intestinal metaplasia (IM) was associated with interval gastric cancer (OR 4.85, 95% CI 1.86–12.69). For gastric cancer, the most common abnormalities in the first ‘cancer-negative’ endoscopy prior to diagnosis were IM (41%), gastritis (36%) and gastric atrophy (31%). For oesophageal cancer, the equivalent abnormalities were gastritis (40%), oesophagitis (33%), nodularity (18%), stricture (16%) and food bolus obstruction (10%). Conclusions There is little difference in demographic characteristics between interval and incident UGI cancers, however there are distinctions in presenting symptoms and endoscopic findings. Abnormalities found at the initial endoscopy prior to diagnosis of interval cancers are common.