Are Metastatic Central Lymph Nodes (D3 volume) in right-sided Colon Cancer a Sign of Systemic Disease? A sub-group Analysis of an Ongoing Multicenter Trial

Abstract

Objective: Assess outcomes of patients with right-sided colon cancer with metastases in the D3 volume after personalized surgery. Background: Patients with central lymph node metastasis (D3-PNG) are considered to have a systemic disease with a poor prognosis. A 3-dimensional definition of the dissection volume allows the removal of all central nodes. Methods: D3-PNG includes consecutive patients from an ongoing clinical trial. Patients were stratified into residual disease negative (D3-RDN) and residual disease positive (D3-RDP) groups. D3-RDN was further stratified into four periods to identify a learning curve. A personalized D3 volume (defined through arterial origins and venous confluences) was removed “en bloc” through medial-to-lateral dissection, and the D3 volume of the specimen was analyzed separately. Results: D3-PNG contained 42(26 females, 63.1SD9.9 y) patients, D3-RDN:29(17 females, 63.4SD10.1 y), and D3-RDP:13(9 females, 62.2SD9.7 y). Mean overall survival (OS) days D3-PNG:1230, D3-RDN:1610, D3-RDP:460. Mean disease-free survival (DFS) was D3-PNG:1023, D3-RDN:1461, D3-RDP:74 days. The probability of OS/ DFS in D3-PNG:52.1%/50.2%, D3-RDN:72.9%/73.1%, D3-RDP: 7.7%/0%. There is a significant change in OS/DFS in the D3-RDN from 2011-2013 to 2020-2022(both P=0.046) and from 2014-2016 to 2020-2022 (P=0.028 and P=0.005,respectively). Conclusion: Our results indicate that surgery can achieve survival in most patients with central lymph node metastases by removing a personalized and anatomically defined D3 volume. The extent of mesenterectomy and the quality of surgery are paramount since a learning curve has demonstrated significantly improved survival over time, despite the low number of patients. These results imply a place for the centralization of this patient group, where feasible.