The examination of lymph nodes following surgery for colorectal cancer

Abstract

Background: The number of lymph nodes (LN) harvested following colorectal cancer (CRC) resection is important for accurate LN stage discrimination and has been considered as a quality marker in the surgical treatment of CRC. Stage discrimination is critical to ensure that patients receive the optimal treatment for their disease stage and to provide prognostic information for the patient. Aims: To identify factors that independently predicted LN harvest (LNH), study the impact of national guidelines and audit had on LNH at national level and to examine the impact that LNH has on survival of node negative and node positive CRC. Methods: Data on patients having CRC resection at unit and national level were studied, and multivariate statistical modelling used to determine independent predictors of harvest and survival. Results: The reporting pathologist is an independent variable for LNH The operating surgeon did not influence LNH Inter unit variability in LNH exists National audit against national standards improved nodal yield at a national level Increasing LNH independently predicted survival in Dukes’ stage B CRC, up to a level of 15 nodes per patient. Lymph node ratio (LNR) independently predicted survival in Dukes’ C CRC and may be a more sensitive prognostic indicator than current lymph node staging systems. Conclusions: The principal conclusions of this thesis were that LNH is an appropriate quality indicator of combined pathological and surgical activity, but not surgery in isolation. National audit against national guidelines has improved LNH in Wales. Survival differences in node negative CRC up to a level of fifteen nodes suggests that the current national guidelines of twelve nodes per patient should be increased. LNR was found to predict survival in CRC patients suggesting it might be appropriate to include LNR in future staging systems for CRC