{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,30]],"date-time":"2026-10-30T21:06:44Z","timestamp":1793394404368,"version":"4.5.0"},"reference-count":37,"publisher":"Public Library of Science (PLoS)","issue":"4","license":[{"start":{"date-parts":[[2025,4,16]],"date-time":"2025-04-16T00:00:00Z","timestamp":1744761600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100008018","name":"Victorian Cancer Agency","doi-asserted-by":"publisher","award":["Mid-Career Research Fellowship Grant"],"award-info":[{"award-number":["Mid-Career Research Fellowship Grant"]}],"id":[{"id":"10.13039\/100008018","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Australasian Gastro-Intestinal Trials Group (AGITG)\/GI Cancer Institute","award":["Innovation Grant"],"award-info":[{"award-number":["Innovation Grant"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec024\">\n<jats:title>Introduction<\/jats:title>\n<jats:p>Early detection of peritoneal disease, especially micro-metastases, in patients with gastroesophageal adenocarcinoma is critical as it alters therapeutic intent, providing a vital opportunity to personalise treatment. However, our ability to accurately stage the peritoneum is inadequate. Tumour-derived DNA in peritoneal lavage fluid (ptDNA) has been suggested to be more sensitive than current methods to stage the peritoneum. Accordingly, this study will determine whether ptDNA is a biomarker of peritoneal micro-metastasis and evaluate its prognostic value in patients with gastroesophageal adenocarcinoma undergoing curative-intent treatment.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec025\">\n<jats:title>Methods and analysis<\/jats:title>\n<jats:p>This will be an Australian multi-centre prospective observational cohort study enrolling patients undergoing routine staging laparoscopy and subsequent curative-intent treatment (either upfront surgery or perioperative chemo-\/radiotherapy and surgery) for gastric and gastroesophageal junction adenocarcinoma. Tumour biopsies, blood and peritoneal lavage fluid will be collected at the time of staging laparoscopy for all patients. A subset of patients will have blood and peritoneal fluid collected at the time of surgical resection, and blood collected at the first post-operative clinic. These biospecimens will undergo genomic and methylomic analysis to detect tumour DNA. ptDNA status will be correlated to disease free survival, peritoneal-specific event free survival, overall survival, sites of treatment failure, histopathological features, and peritoneal lavage cytology status.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec026\">\n<jats:title>Registration<\/jats:title>\n<jats:p>This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12624000451505p).<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0318615","type":"journal-article","created":{"date-parts":[[2025,4,16]],"date-time":"2025-04-16T17:40:21Z","timestamp":1744825221000},"page":"e0318615","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":4,"title":["Multi-omics evaluation of peritoneal fluid in gastroesophageal cancer (OMEGCA): protocol for a prospective multicentre cohort study to detect occult 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