Lymph Node Yield and Colorectal Cancer Survival: A Bowel Cancer Outcomes Registry Cohort Study
Bruce D Wilkie1,2,3, James M Chan1, Elizabeth Paratz2,4
1Department of Surgery, Eastern Health, Box Hill, Victoria, Australia.
Background:
The current standard for lymph node (LN) sampling in colorectal cancer (CRC) surgery is a minimum of 12 LNs. Emerging evidence suggests higher LN yields may improve disease-free survival (DFS); however, an "optimal" number of LNs has yet to be definitively established. The aim of this study was to correlate LN yield with survival outcomes in patients undergoing surgery for nonmetastatic CRC.
Methods:
The Bowel Cancer Outcomes Registry (BCOR) is a clinical quality registry in Australia and New Zealand. Post-operative patients aged ≥ 18 years with histologically confirmed CRC, nonmetastatic disease at diagnosis and with follow-up status documented were included. Post-operative outcomes and survival were assessed with logistic regression. The primary endpoint was CRC-specific mortality. Secondary endpoints were CRC recurrence and all-cause mortality.
Results:
Of 91 271 patient episodes, 10 616 individual eligible patients were identified (45.4% male, n = 4828). The median number of LNs resected was 18 [quartiles 0-12, 13-17, 18-23 and > 23]. A significant difference in CRC-specific mortality was seen between quartiles (p = 0.023), with the primary significant difference demonstrated between the lowest quartile (≤ 12 LNs) and other groups. On long-term follow-up, CRC recurrence and CRC-specific mortality were higher in the group with ≤ 12 LNs resected (16.0% vs. 14.0%, adjusted p = 0.049 and 4.5% vs. 3.3%, adjusted p = 0.037 respectively).
Conclusion:
This study supports the current consensus that > 12 LNs are required for adequate staging and oncological clearance in CRC surgery, and demonstrates yields ≤ 12 LNs are associated with higher CRC recurrence and mortality.
