SP3.1.4 Benign Lymph Node Ratio (LNR) and Lymph Node Yield (LNY) as predictors of survival in resected colorectal cancer (CRC)

Abstract

Abstract Background Lymphadenectomy is central to tumor prognosis. 12 LNY during CRC resection is a standard of good oncological resection, but 30–50 percent of resections do not achieve this. LNR was suggested to be a more accurate predictive factor. Aim To examine the prognostic significance of LNY and LNR on survival in patients with non-metastatic CRC. Methods A retrospective study on patients with CRC treated at a DGH from January 2015 to February 2017. Outcome measures were Disease-Free (DFS) and Overall Survival (OS). Results 265 cases were identified. The mean age was (71.4±11.3) years with a median follow-up of 56 (range 0–72) months. Median LNY was 18 (range 0–66) nodes. 74.9% of the cases have> 12 LNY and only 25.1% of the cases have < 12 LN yielded in the specimen; however, 76.4% have LNR of 0-<0.25. Increasing LNR was associated with poorer OS and DFS (p-value 0.0001). An LNR of (0.75–1) was associated with a very poor prognosis (p-value 0.0001); it showed 30 and 33 months less in median OS and DFS retrospectively than LNR (0-<0.25). LNY did not show any statistically significant predictive factor in survival. Multivariate analysis showed OS and DFS are affected (R2= 27.3% and 26.1% retrospectively) mainly by LNR. It did not show statistical significance with the other variables, including TNM, LNY, and Dukes' stages. Conclusion Increasing LNR was a marker of poor survival; however, LNY was not a statistically significant predictive factor. LNR is better in predicting survival than TNM and Dukes' staging.