Adjuvant HIPEC procedure: access to the abdominal cavity by laparoscopy or laparotomy under general anaesthesia, adhesiolysis if necessary, complete staging of the intra-abdominal cavity, positioning of in- and outflow catheters, perfusion with a minimum of 2l isotonic dialysis fluid at a flow rate of 1-2l/min and an inflow temperature of 42-43˚C. Before the beginning of HIPEC, 5-fluorouracil 400 mg/m2 and leucovorin 20 mg/m2 will be administered intravenously to potentiate oxaliplatin activity. Oxaliplatin (460 mg/m2) is added to the perfusate after attaining at least 42 degrees inflow temperature with a total of 30 minutes perfusion time.