Making sense of the latest breast cancer findings

By Colleen Steelquist, Hutchinson Center Science Editor

Headlines last week proclaimed “Lymph node removal not necessary for breast cancer patients” based on study findings published Feb. 9 in The Journal of the American Medical Association. As is often the case in medical and science news, the truth behind the splashy headlines is not as simple as it sounds.

Currently, most breast cancer patients have one or two “sentinel” lymph nodes removed and tested as part of their surgery to detect if the cancer has spread beyond the breast. If tumor cells are found, more nodes are removed and tested in a procedure called an axillary dissection that can cause painful short- or long-term side effects like swelling and limited arm mobility.

In a five-year clinical study, which enrolled nearly 900 women at 115 sites nationwide, patients with early stage breast cancers had lumpectomies (breast-sparing surgery that only removes tumors) as well as chemotherapy, radiation and hormonal therapy. All of the women had a sentinel node removed and tested as part of their surgery; everyone in the study had cancer in these nodes. Additional lymph nodes were taken in only half of the women.

The study found that breast cancer patients who had multiple lymph nodes removed had the same outcomes as women who had only had their sentinel nodes taken. About 92 percent of women were alive after five years, whether or not the extra lymph nodes were removed, according to the National Cancer Institute-funded research.

People who gleaned the news via headlines might believe node removal is now an antiquated procedure. Not so fast.

Dr. Julie Gralow, director of breast medical oncology at Seattle Cancer Care Alliance, the Hutchinson Center’s clinical arm, said she and her SCCA colleagues have changed their advice to certain patients as a result of the findings, which were presented last June at medical meetings.

“We decided that for patients who met the exact criteria of the study, we would tell them it was now an option not to have their lymph nodes removed,” said Gralow in a recent interview with USA Today.

These results are part of an ongoing evolution toward less invasive approaches in the most common cancer in women worldwide. However, it is noteworthy that axillary dissections will continue in the 80 percent of women with invasive breast cancer for whom they are beneficial.

Dr. Ben Anderson, director of SCCA’s breast health clinic and head of the Hutchinson Center’s Breast Health Global Initiative, further explained the reach—and limits—of the findings in a Patient Power interview last week.

“There’s clearly a group of women who do not have to have the rest of the nodes taken out,” he said. “The tricky part is how do we know which women those are?” He said he and his SCCA colleagues are reticent to apply these findings to women under 50, as breast cancer in younger women tends to be more aggressive and recur more frequently.

Anderson said the extent of node involvement is also often a key factor in directing care. “If the oncologist prescribing your drug therapy really needs to know how many nodes are positive [cancerous] because the number determines how aggressive your therapy should be, you should probably have the additional nodes out,” he said. “We want to make sure we’re not undertreating patients.”

Anderson urged patients to discuss the study with their doctors to determine if the findings apply to their individual situations.

“This is very good news. We’re learning how to achieve equal results by doing less, but it’s important to not assume that everybody’s the same. Everyone’s situation is somewhat different and we want to do the right thing for every patient, not just patients on average,” he said.

It is a small bit of progress in improving our imperfect knowledge of how to beat cancer, one step at a time.