Minimal number of lymph nodes that need to be examined for adequate staging of colorectal cancer--factors influencing lymph node harvest

Abstract

Background/aims: Accurate assessment of lymphatic node status is an essential component in staging of colorectal cancer and determining the need for adjuvant treatment. The risk of understaging nodal status decreases by increasing the number of examined lymph nodes. Several recommendations have been published for the minimum number of lymphatic nodes that need to be harvested for accurate nodal staging with minimal chance of error, ranging from 6 to 17 lymph nodes. However, the number of harvested lymph nodes is very variable, and this variability is poorly understood. The aim of this study was to determine factors associated with the number of retrieved lymph nodes in patients with colorectal cancer.

Methodology: Clinical and histological characteristics of 177 patients operated for colorectal cancer were analyzed.

Results: In multiple regression analysis, male gender, better tumor differentiation and greater tumor size, as well as the presence of acute inflammation were determined as significant independent predictors of the increased number of resected and examined lymph nodes.

Conclusions: The determination of the minimum number of lymph nodes required for accurate nodal staging of patients with colorectal cancer needs to be individualized.