Comparing 5-Year Survival Rates Before and After Re-stratification of Stage I–III Right-Sided Colon Cancer Patients by Establishing the Presence/Absence of Occult Tumor Cells and Lymph Node Metastases in the Different Levels of Surgical Dissection

Abstract

Background To establish the impact of re-stratification on the outcomes of patients (stage I–III right-sided colon cancer) based on the presence/absence of occult tumor cells (OTC) and/or metastatic lymph nodes in the different levels of surgical dissection. Methods Consecutive patients were drawn from a multicenter prospective trial. After surgery, the surgical specimen was divided into the D1/D2 and D3 volumes before being further analyzed separately. All lymph nodes were examined with cytokeratin CAM 5.2 immunohistochemically. Lymph nodes containing metastases and OTC (micrometastases; isolated tumor cells) were identified. Re-stratification was as follows: RS1, stages I/II, no OTC in D1/D2 and D3 volumes; RS2, stages I/II, OTC in D1/D2 and/or D3; RS3, stage III, lymph node metastases in D1/D2, with/without OTC in D3; RS4, stage III, lymph node metastases in D3, with/without OTC in D3. Results Eighty-seven patients (39 men, 68.4 + 9.9 years) were included. The standard stratified (SS) group contained the following: stages I/II (SS1) 57 patients; stage III (SS2) 30 patients. Re-stratified (RS) contained RS1 (38), RS2 (19), RS3 (24), and RS4 (6) patients. Lymph node ratio (OTC) RS2: 0.157 D1/D2; 0.035 D3 and 0.092 complete specimens. Lymph node ratio RS3: 0.113 D1/D2; complete specimen 0.056. Overall survival and disease-free survival were p = 0.875 and p = 0.049 for SS and p = 0.144 and p = 0.001 for RS groups, respectively. Conclusion This re-stratification identifies a patient group with poor prognosis (RS4). Removing this group from SS2 eliminates all the differences in survival between RS2 and RS3 groups. The level of dissection of the affected nodes may have an impact on survival. Clinical Trial “Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic Multi-Detector Computed Tomography (MDCT) Angiography” registered at http://clinicaltrials.gov/ct2/show/NCT01351714

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

“…Our results demonstrate a projected OS/DFS of 72.9/73.1% for D3-RDN patients and a steady 6.7% 11 flow of D3-PNG patients through the years. The OS and DFS in our patient group differ substantially from what is found in the literature.…”

“…Banipal et al report 6 patients (6.9% of 87 patients, LNR:0.43) with OS and DFS at 50%, results from our ongoing trial from the initial period 2011 to 14 presented in Fig. 4 11 . Toyota reports OS among 8 patients (4% of 197) with positive apical nodes to be 32% in 1995 6 .…”

“…The main picture shows the operative area with separate marked D1/D2 volume and D3 volume in relation to the superior mesenteric artery and superior mesenteric vein. *From “Banipal et al 11 Copyright 2022 by Springer Nature. Reprinted under Creative Commons attribution 4.0 international license.…”

“…The few studies that compared conventional colectomy 8–10 to CME showed no difference in survival. It is important to stratify patients in groups with and without central LNM since these can follow the oncological or the linear spreading pathway claiming systemic disease or not 11 …”

“…It is important to stratify patients in groups with and without central LNM since these can follow the oncological or the linear spreading pathway claiming systemic disease or not. 11 Currently, the only available definition of the "D3 volume" of the right colon, as a 3-dimensional structure, is described by Spasojevic et al in 2013. 12 It is based on the patient's individual anatomy, and in this way identifies the central lymph nodes to be harvested.…”