The goal of this clinical trial is to assess if circulating tumor DNA, as assessed by Signatera tumor-informed MRD assay, can guide de-escalation of adjuvant therapy in patients with resectable Stage II-IVa Gastric/Gastric-Esophageal Cancer. The main question it aims to answer is:
• To demonstrate if 2-year disease-free survival (DFS) among participants with resectable clinical Stage II-IVa gastric/gastro-esophageal cancer who received neoadjuvant D-FLOT and are ctDNA negative after curative intent R0 surgery receiving adjuvant durvalumab monotherapy is non-inferior to standard of care D-FLOT.
Researchers will compare post-operative ctDNA negative participants who are receiving adjuvant durvalumab monotherapy to those who receive standard of care (D-FLOT) to see if they have similar outcomes.
Participants will be asked to:
* Receive serial ctDNA testing * Visit their study doctor per their standard of care visits about every 3 months for first 2 years and then every 6 months for an additional 3 years * Answer 5 questionnaires about their well-being
Signed and dated informed consent form (ICF) obtained prior to any trial-specific enrollment procedure.
Age is ≥ 18 years-old at the time of ICF signature.
Able to submit adequate archival tumor tissue (eg, 6 to 10 unstained slides at 10 microns (μm) each or 12-19 unstained slides at 5-microns (μm) plus one hematoxylin and eosin slide (see study lab manual) obtained per standard of care procedures for submission to a central laboratory for Signatera testing OR prior commercial Signatera Genome test results.
Histologically confirmed adenocarcinoma of the stomach, esophagus and/or gastroesophageal junction (GEJ), resectable clinical Stage II-IVa per AJCC 9th edition.
Histologic presence of adenosquamous cell carcinoma, squamous cell carcinoma, gastrointestinal stromal tumor, or neuroendocrine tumors.
Radiographic evidence of unresectable metastatic disease (ie, IVb).
Presence of peritoneal dissemination.
Any prior therapy (eg, radiation, chemoradiation, chemotherapy) for gastric or gastroesophageal cancer other than neoadjuvant D-FLOT and R0 curative intent surgery.