Lymph node removal influences outcome in colon cancer

Reported by Susan Aldridge, PhD, medical journalist

Colon cancer survival is dependent upon the number of lymph nodes removed, according to a new analysis.
Colon cancer can spread through the body via the lymph nodes, so removing them is important in containing and curing the disease. Researchers at the University of Texas M.D. Anderson Cancer Center now reveal that the number of lymph nodes removed can affect survival in colon cancer.

They surveyed 17 different studies. One of them was a national clinical trial involving over 3,200 patients and showed that those who had more than 20 lymph nodes removed had a 14 per cent survival advantage over those who had fewer than 11 nodes removed - this data referring to stage II disease. In stage III disease, the survival advantage was greater still - 23 per cent higher if more than 40 nodes were removed compared to those having fewer than 11 nodes removed. All but one of the studies of stage II cancer showed a strong relationship between the number of nodes removed and improved outcome, and four of six studies of more advanced cancer showed the same. The findings should encourage surgeons to remove lymph nodes during colon cancer surgery more often - currently, this is only done in around one third of cases. The procedure can be difficult to do - the surgeon has to trace back the origin of the blood vessels closest to the tumor, as the lymphatic vessels, and their nodes, are closely associated with them. This is especially tricky when the patient is obese or the nodes are small.

Source
Journal of the National Cancer Institute 21st March 2007