Perioperative Systemic Therapy for Isolated Resectable Colorectal Peritoneal Metastases

This is a multicentre, open-label, parallel-group, phase II-III, superiority study that randomises patients with isolated resectable colorectal peritoneal metastases in a 1:1 ratio to receive either perioperative systemic therapy and cytoreductive surgery with HIPEC (experimental arm) or upfront cytoreductive surgery with HIPEC alone (control arm).

Sex

All

Minimum age

18 Years

Eligible patients are adults who have:

* a World Health Organisation (WHO) performance status of ≤1;
* histological or cytological proof of PM of a non-appendiceal colorectal adenocarcinoma with ≤50% of the tumour cells being signet ring cells;
* resectable disease determined by a diagnostic laparoscopy/laparotomy in combination with abdominal computed tomography and/or magnetic resonance imaging (MRI); only in patients in whom diagnostic laparoscopy or laparotomy is considered not feasible or valuable (e.g. due to known adhesions impeding adequate PCI scoring), it is also allowed to determine resectability by CT or MRI only (provided that the colorectal PM are histologically or cytologically proven);
* no evidence of systemic colorectal metastases within three months prior to enrolment;
* no systemic therapy for colorectal cancer within six months prior to enrolment;
* no contraindications for CRS-HIPEC;
* no previous CRS-HIPEC;
* no concurrent malignancies that interfere with the planned study treatment or the prognosis of resected colorectal PM.

Importantly, enrolment is allowed for patients with radiologically non-measurable disease. Enrolment is also allowed for patients who are referred to a study centre after a macroscopically complete resection of colorectal PM in a referring centre, since it is assumed that microscopic (and often macroscopic) colorectal PM are still present. The diagnostic laparoscopy/laparotomy may be performed in a referring centre, provided that the peritoneal cancer index (PCI) is appropriately scored and documented before enrolment.

Patients are excluded in case of any comorbidity or condition that prevents safe administration of the planned perioperative systemic therapy, determined by the treating medical oncologist, e.g.:

* Inadequate bone marrow, renal, or liver functions (e.g. haemoglobin \<6.0 mmol/L, neutrophils \<1.5 x 109/L, platelets \<100 x 109/L, serum creatinine \>1.5 x ULN, creatinine clearance \<30 ml/min, bilirubin \>2 x ULN, serum liver transaminases \>5 x ULN);
* Previous intolerance of fluoropyrimidines or both oxaliplatin and irinotecan;
* Dehydropyrimidine dehydrogenase deficiency;
* Serious active infections;
* Severe diarrhoea;
* Stomatitis or ulceration in the mouth or gastrointestinal tract;
* Recent major cardiovascular events;
* Unstable or uncompensated respiratory or cardiac disease;
* Bleeding diathesis or coagulopathy;
* Pregnancy or lactation.

The aforementioned laboratory values and tests are to be determined at the discretion of the physician, e.g. only if the patient is suspect for abnormal conditions tests will be conducted.

• RESULTRovers KP, Bakkers C, Nienhuijs SW, Burger JWA, Creemers GM, Thijs AMJ, Brandt-Kerkhof ARM, Madsen EVE, van Meerten E, Tuynman JB, Kusters M, Versteeg KS, Aalbers AGJ, Kok NFM, Buffart TE, Wiezer MJ, Boerma D, Los M, de Reuver PR, Bremers AJA, Verheul HMW, Kruijff S, de Groot DJA, Witkamp AJ, van Grevenstein WMU, Koopman M, Nederend J, Lahaye MJ, Kranenburg O, Fijneman RJA, van 't Erve I, Snaebjornsson P, Hemmer PHJ, Dijkgraaf MGW, Punt CJA, Tanis PJ, de Hingh IHJT; Dutch Peritoneal Oncology Group and the Dutch Colorectal Cancer Group. Perioperative Systemic Therapy vs Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Alone for Resectable Colorectal Peritoneal Metastases: A Phase 2 Randomized Clinical Trial. JAMA Surg. 2021 Aug 1;156(8):710-720. doi: 10.1001/jamasurg.2021.1642. PMID 34009291
• RESULTRovers KP, Bakkers C, Simkens GAAM, Burger JWA, Nienhuijs SW, Creemers GM, Thijs AMJ, Brandt-Kerkhof ARM, Madsen EVE, Ayez N, de Boer NL, van Meerten E, Tuynman JB, Kusters M, Sluiter NR, Verheul HMW, van der Vliet HJ, Wiezer MJ, Boerma D, Wassenaar ECE, Los M, Hunting CB, Aalbers AGJ, Kok NFM, Kuhlmann KFD, Boot H, Chalabi M, Kruijff S, Been LB, van Ginkel RJ, de Groot DJA, Fehrmann RSN, de Wilt JHW, Bremers AJA, de Reuver PR, Radema SA, Herbschleb KH, van Grevenstein WMU, Witkamp AJ, Koopman M, Haj Mohammad N, van Duyn EB, Mastboom WJB, Mekenkamp LJM, Nederend J, Lahaye MJ, Snaebjornsson P, Verhoef C, van Laarhoven HWM, Zwinderman AH, Bouma JM, Kranenburg O, van 't Erve I, Fijneman RJA, Dijkgraaf MGW, Hemmer PHJ, Punt CJA, Tanis PJ, de Hingh IHJT; Dutch Peritoneal Oncology Group (DPOG); Dutch Colorectal Cancer Group (DCCG). Perioperative systemic therapy and cytoreductive surgery with HIPEC versus upfront cytoreductive surgery with HIPEC alone for isolated resectable colorectal peritoneal metastases: protocol of a multicentre, open-label, parallel-group, phase II-III, randomised, superiority study (CAIRO6). BMC Cancer. 2019 Apr 25;19(1):390. doi: 10.1186/s12885-019-5545-0. PMID 31023318
• DERIVEDRovers KP, Bakkers C, van den Heuvel TBM, van de Vlasakker VCJ, Kerkhoff TME, Nienhuijs SW, Burger JWA, Creemers GM, van Hellemond IEG, Tuynman JB, Kusters M, Buffart TE, Aalbers AGJ, Kok NFM, Chalabi M, Boerma D, Brandt-Kerkhof ARM, de Reuver PR, Hemmer PHJ, van Grevenstein WMU, van der Speeten K, Snaebjornsson P, Lee-Law PY, Lahaye MJ, Nederend J, Kranenburg O, Bouma JM, Punt CJA, Dijkgraaf MGW, Tanis PJ, de Hingh IHJT; CAIRO6 Investigators; Dutch Peritoneal Oncology Group and the Dutch Colorectal Cancer Group. Perioperative systemic therapy versus surgery alone for resectable colorectal peritoneal-only metastases (CAIRO6): a randomised, open-label, phase 3 trial. Lancet Oncol. 2026 Jul;27(7):849-863. doi: 10.1016/S1470-2045(26)00085-9.