Early-stage breast cancer patients who underwent extensive surgery to remove all their lymph nodes fared no better in terms of survival than those who had only a few nodes removed, researchers found in a new study.

The finding challenges the current guideline for early breast-cancer treatment. For some women, only the lymph nodes to which their cancer is most likely to have spread, known as the sentinel lymph nodes, may have to be removed, according to the study appearing tomorrow (Feb. 9) in the Journal of the American Medical Association.

"Tens of thousands of women could probably be treated with less radical surgery," said study researcher Dr. Armando Giuliano, of the John Wayne Cancer Institute at Saint John's Health Center, Santa Monica, Calif.

Avoiding the more extensive surgery, known as axillary lymph node dissection (ALND), which removes all the lymph nodes found in the armpit, would be beneficial because ALND can lead to complications including infection, swelling and shoulder pain.

"I think it is going to have an impact on clinical practice," said Dr. Gary Lyman, a professor of medicine at Duke University, who was not involved in the study. Lyman is chairman of the American Society of Clinical Oncology panel that is revising the organization's guidelines for the biopsy of sentinel lymph nodes in women with early-stage breast cancer. The new guidelines are expected to be released this spring.

However, Lyman said the guidelines may change only for a subset of women who are similar to the patients included in the new study. For instance, those women did not have large, aggressive tumors, Lyman said.

"We can't necessarily extrapolate the results of this to the broader patient population," he said.

The spread of breast cancer

The researchers studied women who'd had a lumpectomy — surgery to remove a breast cancer tumor — and had been treated with radiation. Most also underwent other treatments after surgery, such as chemotherapy.

To determine whether the breast cancer had spread, or metastasized, to their lymph nodes, the researchers performed a procedure called sentinel lymph node dissection (SLND), which removes only the few lymph nodes into which fluid enters first after draining from the breast. They found that in 890 patients, the cancer had spread to one or two of their sentinel lymph nodes.

A subset of these patients, 446 in all, were randomly selected to receive additional surgery, the ALND. The rest received no additional treatment.

After 6.3 years, 94 patients in the study had died: 52 of those who'd had all of their lymph nodes removed, and 42 who'd had only the sentinel lymph nodes removed.

The five-year survival rates of the two groups were very similar: 92.5 percent for the SLND group, and 91.8 percent for the ALND group. And a similar number of patients in both groups were disease-free after five-years: 83.9 percent of those in the SLND group, and 82.2 percent of those in the ALND group.

But the rate of wound infection, swelling or tingling sensations was 70 percent among those who'd undergone ALND, and just 25 percent among those who'd had SLND.

Who might be spared the surgery?

The results suggest "you may be able to select out certain patients who don't need to have all the nodes taken out," said Dr. Anthony Lucci, a professor of surgical oncology at the University of Texas MD Anderson Cancer Center, in Houston, who helped enroll patients in the study. These would be women with limited disease that has spread only to a few lymph nodes and who also receive radiation and a lumpectomy, Lucci said.

Lyman noted that the study did not enroll as many patents as originally planned. But because the two groups were so similar in outcome, accruing more patients is not likely to have changed the conclusion, he said.

Pass it on: Some women with breast cancer that has spread to their lymph nodes may not need additional surgery to remove all of their lymph nodes.

Follow MyHealthNewsDaily staff writer Rachael Rettner on Twitter @Rachael_MHND.