PIPAC for Peritoneal Metastases of Colorectal Cancer

Rationale: repetitive electrostatic pressurised intraperitoneal aerosol chemotherapy with oxaliplatin (ePIPAC-OX) is offered as a palliative treatment option for patients with isolated unresectable colorectal peritoneal metastases (PM) in several centres worldwide. However, little is known about its feasibility, safety, tolerability, efficacy, costs, and pharmacokinetics in this setting. Objectives: to prospectively explore the feasibility, safety, tolerability, preliminary efficacy, costs, and pharmacokinetic profile of repetitive ePIPAC-OX as a palliative monotherapy for isolated unresectable colorectal PM under controlled circumstances. Study design: multicentre, open-label, single-arm, phase II study. Setting: two Dutch tertiary referral hospitals for the surgical treatment of colorectal PM. Study population: adults who have a World Health Organisation (WHO) performance status of 0 or 1, adequate organ functions, histologically or cytologically confirmed unresectable PM of a colorectal or appendiceal carcinoma, no systemic metastases, no symptoms of gastrointestinal obstruction, no contraindications for the planned intervention, and no previous pressurised intraperitoneal aerosol chemotherapy (PIPAC). Intervention: instead of standard palliative treatment, enrolled patients receive laparoscopy-controlled ePIPAC-OX (92 mg/m2 body-surface area \[BSA\]) with intravenous leucovorin (20 mg/m2 BSA) and bolus 5-fluorouracil (400 mg/m2 BSA) every six weeks. Four weeks after each procedure, patients undergo clinical, radiological, and biochemical evaluation. ePIPAC-OX is repeated until clinical, radiological, or macroscopic disease progression, after which standard palliative treatment is (re)introduced. Outcomes: the primary outcome is the number of patients with major toxicity (grade ≥3 according to the Common Terminology Criteria for Adverse Events v4.0) up to four weeks after the last procedure. Secondary outcomes are the environmental safety of ePIPAC-OX, procedure-related characteristics, the number of procedures in each patient and reasons for discontinuation, minor toxicity, organ-specific toxicity, postoperative complications, hospital stay, readmissions, quality of life, costs, progression-free survival, overall survival, and the radiological, histopathological, cytological, biochemical, and macroscopic tumour response. Atomic absorption spectrophotometry is used to measure concentrations of oxaliplatin in plasma, plasma ultrafiltrate, urine, ascites, PM, and normal peritoneum during and after ePIPAC-OX.