Number of Lymph Nodes Tested for Colon CA Up 1988 to 2008
But no significant increase in lymph node positivity during the same period
TUESDAY, Sept. 13 (HealthDay News) -- For patients treated surgically for colon cancer, the number of lymph nodes evaluated increased from 1988 to 2008; however, there was no significant increase in lymph node positivity during the same period, according to a study published in the Sept. 14 issue of the Journal of the American Medical Association.
Helen M. Parsons, M.P.H., from the National Cancer Institute in Bethesda, Md., and colleagues assessed the correlation between extensive lymph node evaluation, identification of lymph node-positive cancers, and the risk of death. Data were evaluated from the Surveillance, Epidemiology, and End Results program between 1988 and 2008 for 86,394 patients who underwent surgery for colon cancer.
The investigators found that the number of evaluated lymph nodes increased between 1988 and 2008 with no significant overall increase in lymph node positivity. There was an increase from 34.6 percent of patients with 12 or more lymph nodes assessed from 1988 to 1990 to 73.6 percent from 2006 to 2008; but the proportion of node-positive cancers did not change with time. Patients with high levels of lymph node evaluation were slightly but significantly more likely to be node-positive (adjusted odds ratio or 30 to 39 nodes versus one to eight nodes, 1.11), and had a significantly lower hazard of death versus patients with fewer nodes evaluated (adjusted hazard ratio for 30 to 39 nodes versus one to eight nodes, 0.66).
"The number of lymph nodes evaluated for colon cancer markedly increased in the past two decades but was not associated with an overall shift toward higher-staged cancers," the authors write.