Offering treatment with potential to cure for participants with no such offer in today's standard treatment options, by offering metastatectomia and standard treatment with intention to cure i.e., neoadjuvant chemotherapy and gastrectomy for participants with gastric- og gastroeusofageal junction cancer. Including 20 participants from all 4 centres in Denmark able to perform the surgical procedures in question.

Endpoints: 2-year overall survival.

Inclusion Criteria:

• Age > 18.
• Presence of primary T1-T4N0-N3M1 adenocarcinoma of the stomach or GEJ and max. 30% liver involvement.
• Primary tumour resectable, based on imaging workup.
• Surgical operable patients with ASA-score36 ≤ III and WHO performance status37 0-1.
• Patients eligible for treatment with systemic chemotherapy by FLOT regimen.
• Informed consent is obtained.

Exclusion Criteria:

• Patient with non-resectable cancer.
• Direct growth involving adjacent organs, i.e., pancreas, colon, blood vessels or bones.
• Other malignant disease diagnosed or treated up to 2 years prior to inclusion, except non-aggressive cancers such as non-melanoma sin cancer.
• Altered anatomy of the upper gastrointestinal tract due to previous surgery of the oesophagus, stomach, and duodenum.
• BMI ≤ 18
• The patient is unable to understand and/or read the consent form.
• Other serious illness or acute infections.
• Pregnant or breastfeeding.