Protocol digest of a randomized controlled trial comparing transverse colectomy with extended right hemicolectomy for Stage II/III transverse colon cancer: JCOG2304 (TACTICS).

Transverse colon cancer is traditionally treated with extended right hemicolectomy (EHC), which involves division of the middle colic, right colic, and ileocolic arteries, along with removal of the terminal ileum and right colon. Transverse colectomy (TC) is a limited resection removing only 10 cm of bowel on either side of the tumor, along with resection of the middle colic artery and regional lymphadenectomy. This approach may contribute to the preservation of bowel function without compromising oncologic adequacy. This multicenter, randomized, phase III trial is designed to evaluate the non-inferiority of TC compared with EHC in terms of relapse-free survival among patients with Stage II/III transverse colon cancer whose main feeding artery is the middle colic artery. In total, 510 patients will be enrolled across major Japanese centers over 5 years. The trial has been registered with the Japan Registry of Clinical Trials (jRCT1030240479).