For years standard practice in breast cancer treatment has gone like this: If a biopsy of one or two "sentinel" lymph nodes near a breast tumor shows cancer has spread, surgeons should cut out other nearby lymph nodes to prevent it from spreading further.
The old conventional wisdom made sense. But a new study in the Journal of the American Medical Association says standard practice is wrong — for tens of thousands of women with a new diagnosis of breast cancer.
"It is counterintuitive, isn't it?" says Dr. Armando Giuliano, chief of breast cancer surgery at John Wayne Cancer Institute in Santa Monica, Calif.
Giuliano led the new study, sponsored by the American College of Surgeons. But he acknowledges the new results are "hard to accept."
"It makes sense to cut it out," Giuliano says, referring to positive lymph nodes. "But it looks like it doesn't really matter."
He has a lot of credibility on this issue. Back in the mid-1990s, Giuliano was instrumental in establishing the current practice of sampling one or two sentinel lymph nodes and then using those results to determine whether other lymph nodes in the area should be excised.
But among 900 women in the new study who had either the conventional approach or no additional lymph node surgery, there was no difference in survival over five years — or in return of their cancer.
When the study started in the late 1990s, its architects expected five-year survival rates of 80 percent. So Giuliano and his co-authors were surprised that over 90 percent of women were alive five years after they had a positive lymph node biopsy.
"That's great news for women," Giuliano says. "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 [lymph node] operation, which has its own attendant complications."
Those complications, for up to 30 percent of women, include chronic, painful swelling, called lymphedema. It can limit many women's use of their arms.
Some think the study results reflect the impact of earlier diagnosis of breast cancer combined with widespread use of chemotherapy and radiation following removal of the primary tumor. Those treatments may make it less important to remove lymph nodes containing metastatic cells.
But study authors caution that there are a lot of unknowns about breast cancer cells found in lymph nodes — they may be biologically different from those that cause real trouble when they migrate to bones, liver and other organs.
The new findings don't apply to all breast cancer patients — just those with early-stage cancer who have lumpectomies followed by whole-breast radiation and chemotherapy. That may be 20 percent of all new breast cancer diagnoses.
Changes In Practice
Giuliano says the study results have changed his practice, and they've started to change other doctors' minds. The results were initially presented last spring at a meeting of the American Society of Clinical Oncology, but many specialists have been waiting for formal publication.
"I'm sure there will be controversy. I'm sure there will be resistance," Giuliano says. "But I think physicians will consider this option in the management of their patients and be less likely to remove lymph nodes."
Maybe not overnight. "Change tends to be slow in medicine," Giuliano says. But some think it won't be 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 says the study is having immediate impact. He is head of breast surgery at Dana-Farber Cancer Institute and Brigham and Women's Hospital in Boston.
"I definitely think it's a big deal," Golshan says. "Anytime you have a study that is going to — and has actually already started to — change practice patterns in breast cancer surgery and treatment, it's a big deal."
He says the new study is not perfect. It enrolled far fewer patients than it originally set out to. He and others would like to have more than five years of follow-up on the study subjects. There are other quibbles that may be resolved when European studies on the issue ripen — a few years from now.
Less Versus More Surgery
For now, Golshan welcomes the findings — especially because, he says, there has been a resurgence of mastectomies despite a string of high-quality studies supporting the effectiveness of breast-conserving lumpectomies.
"I hope this study will bring us back to the notion that less surgery is probably as good as more surgery," Golshan says.
Breast cancer patients are already asking whether they really need a dozen or more lymph nodes removed if a sentinel node is positive. He saw two such patients in his clinic Monday.
"I went through the pluses and minuses," Golshan says. "One woman did not want further surgery, and the other did."
Breast cancer treatment is often a very personal decision, he says, involving a woman's age, her particular kind of cancer, how much disease there appears to be in her lymph nodes, and her attitude about risk and uncertainty. And no one study is going to change that.