Clinical impact of D3 lymph node dissection with left colic artery (LCA) preservation compared to D3 without LCA preservation: Exploratory subgroup analysis of data from JCOG0404

Aim: We investigated the clinical impact of D3 lymph node dissection preserving left colic artery (LCA) compared to D3 without LCA preservation using data from JCOG0404. LCA preservation is expected to maintain adequate blood supply, which is effective in preventing anastomotic leakage, intestinal paralysis, and bowel obstruction. Whether D3 with LCA preservation (Group A) improves clinical outcomes following resection of sigmoid colon cancer compared to D3 without LCA preservation (Group B) is unclear. Methods: Procedure type was identified from photographs of the surgical field collected for central surgical review in JCOG0404. Clinical outcomes were compared between each procedure. Results: Among the 1057 randomized patients in JCOG0404, 631 patients receiving sigmoid colectomy or anterior resection were included in the subgroup analysis. Group A comprised of 135 patients and Group B of 496 patients. Patient backgrounds did not differ between groups. Median operative time, blood loss, anastomotic leakage, and intestinal paralysis were not remarkably different (Group A vs Group B: 185 vs 186 minutes, 60 vs 50 mL, 3.0% vs 5.0%, and 2.2% vs 3.8%). More overall postoperative complications occurred in Group B than Group A (21.6% vs 9.6%, P =.022). Five-year relapse-free survival (RFS) and overall survival (OS) tended to be better in Group A than Group B (RFS: 83.7% and 80.5%, HR 0.80 [95% CI 0.51-1.26], OS: 96.3% and 91.1%, HR 0.41 [95% CI 0.19-0.89]). Conclusions: Short- and long-term outcomes tend to be better in Group A than Group B, indicating that preservation of LCA could be an alternative treatment.