"We're not saying we shouldn't evaluate lymph nodes. It's still important. But using this as a measure for reimbursement, or a marker for quality may have a limited impact on improving survival," she added.
In an accompanying editorial, Dr. Sandra Wong, an assistant professor of surgery at University of Michigan, said the research is more evidence that evaluating lots and lots of lymph nodes after surgery for colon cancer doesn't seem to help cancer patients much.
Wong was the author of a 2007 study that found hospitals that did a lot of node evaluation didn't have better colon cancer survival rates than hospitals that did less.
"The theory that evaluating lots of nodes can help you find more positive nodes isn't holding up," Wong said.
But this study found an association with greater survival, which suggests a "missing link" to explain it.
That missing link may lie in the details of the surgery or what treatment the patient received after surgery, information the researchers weren't able to consider, she said. It's a question worth answering, Wong added.
"There is so much focus on finding these lymph nodes," she said. "Those are resources we could be using to improve cancer care, such as providing more colonoscopies or making sure people who have a positive node get chemotherapy."
The U.S. National Cancer Institute has more on staging colon cancer.
SOURCES: Helen M. Parsons, M.P.H., public health advisor, National Cancer Institute, Bethesda, Md.; Sandra Wong, M.D., assistant professor, surgery, University of Michigan, Ann Arbor; Sept. 14, 2011, Journal of the American Medical Association
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