The relationship of lymph node dissection and colon cancer survival in the Veterans Affairs Central Cancer Registry

Abstract

Background The extent of lymphadenectomy in colon cancer may impact potential to cure and accuracy of staging. Methods The Veterans Affairs Central Cancer Registry database was queried for TNM stage I–III colon adenocarcinoma patients and yielded 5,823 individuals. The number of lymph nodes examined, number positive, and the positive:examined lymph node ratio were studied with respect to overall survival by using log-rank and Kaplan-Meier analysis. Results The overall survival (OS) in stage II patients was greater with the higher number of lymph node (LN) examined. For stage II patients, the 5-year OS was 34%, 43%, 47%, and 55% for the lowest to highest quartiles ( P = .007). For stage III patients, the 5-year OS was 31%, 27%, 38%, and 53% for the lowest to highest quartiles (not significant overall). OS is greater with an increased number of positive lymph nodes ( P < .001). The lymph node ratio was more powerful prognostically with a 5-year OS of 27% for the highest quartile versus 44% for the lowest. Conclusions More extensive lymphadenectomy is associated with improved OS in stage II colon cancer patients. The positive:examined LN ratio is more powerful prognostically than the number of nodes examined or LN positivity.