Impact of lymph node ratio in the colorectal cancer staging system.

Aim: Some researchers have proposed the Lymph Node Ratio (LNR) as a prognostic index for post-surgical colorectal cancer follow up.

Material And Method: Two hundred patients with colorectal cancer (ratio F/M of 2:1) were studied. Patients were divided in subgroups according to N-stage and LNR score, subgroups of LNR were made on quartiles. For each subgroup 5 year survival rate was calculated and comparison between groups was carried out.

Results: There were 104 patients on N0, 38 on N1 and 58 on N2 stage. Survival rate at 5 years was 61.30% for the NO subgroup, 18.70% for the N1 subgroup, and 12.31% for the N2 subgroup (Fig. 1). The most significant p value, was reported between N0 and N1 as well as between N0 and N2 subgroup (p=0.001). Nodes positive were 44 a LNR ranging from 1% to 25% (1% < LNR < 25%); 24 patients from 26% to 50% (26% < LNR < 50%). In 6 patients LNR was ranging from 51% to 75% (51% < LNR 75%) and in 8 patients from 76% to 100% (76% < LNR 100%); overall survival rate in different quartiles was respectively 27.12%, 9.38%, 16.67% and 1.56%.

Conclusion: LNR is a reliable prognostic index in post surgical colorectal cancer staging.