STEVE INSKEEP, host:
And we're going to hear next about a finding that could change the treatment of breast cancer. This study has been published by the Journal of the American Medical Association. And it says many women who have breast cancer cells in their underarm lymph nodes do not need more surgery to remove additional nodes.
NPR's Richard Knox reports the study is already affecting how some women are treated.
RICHARD KNOX: The old conventional wisdom made sense: If a biopsy of one or two lymph nodes near a breast tumor shows cancer has spread, surgeons should cut out other nearby lymph nodes to prevent cancer spreading further. That's been standard practice for decades. But the new study says standard practice is wrong.
Among 900 women who had either the traditional approach or no additional lymph node surgery, there was no difference in survival over five years - or in return of their cancer.
Dr. ARMANDO GIULIANO (John Wayne Cancer Institute): Well, it is counterintuitive, isn't it? It is hard to accept. It makes sense to cut it out, but it looks like it doesn't really matter.
KNOX: That's Dr. Armando Giuliano, a California breast surgeon who led the new study. He was surprised that over 90 percent of women were alive five years after they had a positive lymph node biopsy.
Dr. GIULIANO: And the fact that the women who did not have their lymph nodes removed had just as high a survival is great news because we can avoid that more radical operation that has its own attendant complications.
KNOX: Removal of a dozen or more underarm lymph nodes often causes chronic, painful swelling that can limit many women's use of their arm.
Giuliano says the study results have changed his practice, and it's starting to change other doctors' minds.
Dr. GIULIANO: I'm sure there'll be controversy. I'm sure there'll be resistance, but I think physicians will consider this option in the management of their patients and be less likely to remove lymph nodes. Change tends to be slow in medicine.
KNOX: But maybe not as slow as breast surgeons were to accept a similar idea back in the 1970s and '80s, when mastectomy was gradually replaced by lumpectomy.
Dr. Mehra Golshan, head of breast surgery at Dana Farber Cancer Institute in Boston, also says the new study is having immediate impact.
Dr. MEHRA GOLSHAN (Dana Farber Cancer Institute): I definitely think it's a big deal. I mean, you know, any time you have a study that is going to - and has actually already started to change practice pattern in breast cancer surgery and treatment, it's a big deal.
KNOX: But it doesn't apply to all breast cancer patients - just those with early-stage cancer who have lumpectomies followed by radiation and chemotherapy. That may be 20 percent of all new breast cancer diagnoses. Golshan saw two such women in his clinic just yesterday.
Dr. GOLSHAN: I went through the pluses and minuses of the findings. And one woman, I can tell you, did not want further surgery and the other one did.
KNOX: He says breast cancer treatment is a very personal decision involving a lot of factors. And no one study is going to change that.
Richard Knox, NPR News.