Neoadjuvant chemotherapy for obstructive colon cancer derived by a stoma: Study protocol of the FRENCH-01 randomized phase III trial (COnCERTO Trial).

[BACKGROUND] Obstructive colon cancer (OCC) is at poor prognosis, and the high morbidity of emergency resection frequently delays or precludes adjuvant chemotherapy. A strategy with first step diverting stoma - neoadjuvant chemotherapy (NAC) - colectomy in non-metastatic OCC may represent an alternative to the conventional strategy of stoma followed by colectomy.

[METHOD] COnCERTO is a multicenter, open-label, randomized (1:1), phase III trial evaluating NAC followed by colectomy ± adjuvant chemotherapy versus standard-of-care colectomy ± adjuvant chemotherapy in adults with resectable non-metastatic MSS OCC first treated by a defunctionning stoma. Two hundred and thirty-two will be randomized across 37 French centers. The primary endpoint is the rate of complete curative therapeutic sequence combining the resection of the primary and the administration of scheduled NAC and/ or adjuvant chemotherapy. Secondary endpoints include the tolerance and compliance of NAC and/ or adjuvant chemotherapy (SRAE ≥ grade 3, CTCAE v5.0), quality and completeness of the surgical excision, 90 days postoperative morbidity, health-related quality of life, OS and DFS at 3 years and survival without stoma at 3 years. Randomization started in May 2024.

[DISCUSSION] COnCERTO will determine whether a NAC approach can be pursued safely and effectively in localized OCC and translate into a better cancer control and quality of life improvement.

[REGISTRATION NUMBER] ClinicalTrials.gov NCT06107920.