Burlington, Vermont - January 19, 2011
When women are diagnosed with breast cancer, one of the first steps is to check their lymph nodes. A procedure pioneered by a University of Vermont surgeon is now standard of practice worldwide. Just a few nodes, called the sentinel nodes, are now removed and checked for cancer.
But pathologist Donald Weaver wanted to know more. If those nodes are negative, could tiny metastases-- small clusters of cancer cells-- still be present? And if so, did they make a difference in a woman's survival?
"We examined with outcome data 3,887 patients, roughly 4,000 patients which was our design intent with the trail. We found 616 patients had occult metastases, high gave us a lot of power to look at outcomes," Weaver said.
That finding itself didn't surprise Weaver and he says patients who thought they didn't have cancer in their lymph nodes because initial tests showed them to be sentinel node negative shouldn't be alarmed either.
"That probably does initially alarm people, but I would say they should be alarmed. We've known since 1945 that these metastases are there and they usually get blended into the patients who are classified as node negative. In fact, the outcomes with women who have node negative breast cancer is excellent," Weaver said.
In fact, Weaver's research showed that even when micrometastases are present, they had little impact on overall survival. There was just a 1.2 percent difference five years out between those node negative patients who had them and those who did not.
"Because the outcome differences are so small it probably isn't cost effective and it's not clinically meaningful to pursue these metastases at all," Weaver said.
New information that will undoubtedly provide guidance to those doctors diagnosing and treating breast cancer-- one of the leading killers of women nationwide.
Bridget Barry Caswell - WCAX News
PO Box 4508