The Value of Incisura in Gastric Intestinal Metaplasia Surveillance
QUEK SXZ1,2, Jonathan LEE1,2,3, Calvin J KOH1,2,3, Feng ZHU2,3, Jimmy SO3,4, Khek Yu HO1,2, Supriya SRIVASTAVA2, Stephen TSAO5, Christopher KHOR6, Kwong Ming FOCK7, Wee Chian LIM5, Khoon Lin LING8, Tiing Leong ANG7, Ming TEH3,9, Khay Guan YEOH1,2,3
Affliations:
1Division of Gastroenterology and Hepatology, National University Hospital, Singapore
2Department of Medicine, National University of Singapore, Singapore
3Singapore Gastric Cancer Consortium, Singapore
4Department of Surgery, National University of Singapore, Singapore
5Department of Gastroenterology & Hepatology, Tan Tock Seng Hospital, Singapore
6Department of Gastroenterology & Hepatology, Singapore General Hospital, Singapore
7Department of Gastroenterology & Hepatology, Changi General Hospital, Singapore
8Mount Elizabeth Medical Centre, Singapore
9Department of Pathology, National University of Singapore, Singapore
Corresponding email address:
Sabrina QUEK (Sabrina_quek@nuhs.edu.sg)
Background/Aim: Gastric intestinal metaplasia (GIM) is a precancerous lesion for gastric cancer. Histopathological assessment is based on the updated Sydney system and the operative link on gastric IM (OLGIM). Although the incisura has been proposed to have the highest incidence and severity of GIM, previous publications did not demonstrate additional benefit in its inclusion. We aim to determine the diagnostic yield and value of cancer risk stratification of GIM using biopsy protocols which include and exclude the incisura.
Methods: 2761 Chinese subjects aged 50 years and above, completing a total of 7616 endoscopies were recruited. All subjects had protocolized gastric biopsies in accordance with the updated Sydney protocol and standardized for OLGIM histological reporting, performed by gastrointestinal pathologists.
Results: GIM was present in 46.7% (n=3555) of endoscopies. The prevalence of incisura GIM was 44.3% (n=1574). Presence of GIM in the incisura was associated with high-risk OLGIM stages (OLGIM II-IV) (OR5.19 (95%CI 4.93 – 6.14, p<0.01)). 6.1% (n=218) of cases with GIM would have been missed without sampling the incisura. By including the incisura, OLGIM scores generally upstaged 6.3% for low-risk GIM (OLGIM I). Excluding the incisura down-staged 30.5% for high-risk OLGIM, with 16.7% (n=3/18) of subsequent early gastric neoplasia (EGN) in our prospective endoscopic surveillance cohort being down-staged from high-risk to low-risk OLGIM.
Conclusion: Incisura sampling increases the yield of GIM detection and more accurately risk stratifies GIM. It should be routinely included in the protocol for GIM staging.