Systemic Antitumor Treatment with or Without Pressurized Intraperitoneal Aerosol Chemotherapy for Colon Peritoneal Metastases (PIPOX02)

Prior treatment

• History of abdominal fistula, gastrointestinal perforation, intra-abdominal abscess within 6 months prior to enrolment;

Other illness

• Other cancer treated within the last 3 years, with the exception of in situ cervical carcinoma or basocellular carcinoma;
• Rectal cancer primary (tumor \<15 cm from the anal verge);
• Extraperitoneal polymetastatic diseases. (Only oligometastatic1 diseases are allowed for inclusion);
• Active gastrointestinal bleeding;
• Inflammatory bowel disease;

Other

• Mutational status corresponding to microsatellite instability high (MSI-H) or mismatch repair deficient (dMMR);
• Complete or partial bowel obstruction unresponsive to medical treatment;
• Peripheral neuropathy according to the Common Toxicity Criteria for Adverse Events (CTCAE) version 5.0, grade ≥2

• ECOG performance status of 0 to 2;
• Histopathologically confirmed colonic adenocarcinoma with synchronous or metachronous peritoneal metastasis (PM);
• Unresectable PM defined as any of the following:
  • PCI \>15
  • Extended small bowell involvement
  • Poor general condition contra-indication to a major abdominal surgery (eg: a complete cytoreductive surgery), as decided by the medico-surgical team of the investigator's site specialised in peritoneal carcinomatosis in charge of the patient.
• A surgical exploration performed less than 4 weeks before inclusion (if not, a laparoscopic exploration must be performed);
• First line systemic chemotherapy for advanced / metastatic colonic adenocarcinoma. Systemic chemotherapy in an adjuvant setting is allowed if completed more than 6 months before recurrence and without persistent oxaliplatin-induced neuropathy;
• No extended intraperitoneal adherences defined by at least 9 out of 13 abdominal regions correctly explored during surgical exploration (laparoscopy or laparotomy;