Prognostic Value of Lymph Node Ratios in Node Positive Rectal Cancer Treated with Preoperative Chemoradiation


Background: To investigate the impact of the lymph node ratio (LNR) on the prognosis of patients with locallyadvanced rectal cancer undergoing pre-operative chemoradiation.
Methods: Clinicopathologic and follow up dataof 128 patients with stage III rectal cancer who underwent curative resection from 1996 to 2007 were reviewed.The patients were divided into two groups according to the lymph node ratio: LNR ≤0.2 (n=28), and >0.2 (n=100).Kaplan-Meier and the Cox proportional hazard regression models were used to evaluate the prognostic effectsaccording to LNR.
Results: Median numbers of lymph nodes examined and lymph nodes involved by tumourwere 10.3 (range 2-28) and 5.8 (range 1-25), respectively, and the median LNR was 0.5 (range, 0-1.6). The 5-yearsurvival rate significantly differed by LNR (≤0.2, 69%; >0.2, 19%; Log-rank p value < 0.001). LNR was alsoa significant prognostic factor of survival adjusted for age, sex, post-operative chemotherapy, total number ofexamined lymph nodes, metastasis and local recurrence (≤0.2, HR=1; >0.2, HR=4.8, 95%CI=2.1-11.1) and asignificant predictor of local recurrence and distant metastasis during follow-up independently of total number ofexamined lymph node.
Conclusions: Total number of examined lymph nodes and LNR were significant prognosticfactors for survival in patients with stage III rectal cancer undergoing pre-operative chemoradiotherapy.