HOUSTON - An analysis of 17 studies from nine countries has found that the more lymph nodes that are removed and examined during surgical treatment of colon cancer, the better the outcome appears to be for patients. The study suggests that removal of the nodes takes away a reservoir for potentially lethal cancer, and that knowing how far a cancer has spread leads to tailored and more beneficial treatment, according to researchers at The University of Texas M. D. Anderson Cancer Center.
Investigators say the findings, reported in the March 21 issue of the Journal of the National Cancer Institute, encourage a dialogue amongst physicians regarding the number of lymph nodes removed by surgeons and evaluated by pathologists as a measure of the quality of care that colon cancer patients receive.
"Currently just over one-third of colon cancer patients in the United States are getting an adequate lymph node evaluation," says the study's lead author, George Chang, M.D., assistant professor in the Department of Surgical Oncology at M. D. Anderson.
The results of this study were striking and should help support efforts now ongoing by some medical professional societies and expert panels to consider a minimum number of lymph nodes be extracted and examined during the surgery, continues Chang.
For example, the research team reports that one of the 17 studies examined, a national clinical trial enrolling more than 3,200 patients to look at the effects of chemotherapy on colon cancer recurrence after surgical resection, demonstrated a 14 percent increase in five-year survival if more than 20 lymph nodes were examined, compared to less than 11 nodes among patients who have Stage II cancers. The survival advantage was even greater - 23 percent - in patients with Stage IIIA and IIIB cancer if more than 40 nodes were evaluated, compared with less than 11 nodes.