A new study finds that many women with early breast cancer do not need a painful procedure that has long been routine: removal of cancerous lymph nodes from the armpit.
As reported by The New York Times The discovery turns standard medical practice on its head. Surgeons have been removing lymph nodes from under the arms of breast cancer patients for 100 years, believing it would prolong women’s lives by keeping the cancer from spreading or coming back.
Now, researchers report that for women who meet certain criteria — about 20 percent of patients, or 40,000 women a year in the United States — taking out cancerous nodes has no advantage. It does not change the treatment plan, improve survival or make the cancer less likely to recur. And it can cause complications like infection and lymphedema, a chronic swelling in the arm that ranges from mild to disabling.
Removing the cancerous lymph nodes proved unnecessary because the women in the study had chemotherapy and radiation, which probably wiped out any disease in the nodes, the researchers said. Those treatments are now standard for women with breast cancer in the lymph nodes, based on the realization that once the disease reaches the nodes, it has the potential to spread to vital organs and cannot be eliminated by surgery alone.
Experts say that the new findings, combined with similar ones from earlier studies, should change medical practice for many patients. Some centers have already acted on the new information. Memorial Sloan-Kettering Cancer Center in Manhattan changed its practice in September, because doctors knew the study results before they were published. But more widespread change may take time, experts say, because the belief in removing nodes is so deeply ingrained.
“This is such a radical change in thought that it’s been hard for many people to get their heads around it,” said Dr. Monica Morrow, chief of the breast service at Sloan-Kettering and an author of the study, which is being published Wednesday in The Journal of the American Medical Association. The National Cancer Institute paid for the study.
Doctors and patients alike find it easy to accept more cancer treatment on the basis of a study, Dr. Morrow said, but get scared when the data favor less treatment.
The new findings are part of a trend to move away from radical surgery for breast cancer. Rates of mastectomy, removal of the whole breast, began declining in the 1980s after studies found that for many patients, survival rates after lumpectomy and radiation were just as good as those after mastectomy.
The trend reflects an evolving understanding of breast cancer. In decades past, there was a belief that surgery could “get it all” — eradicate the cancer before it could spread to organs and bones. But research has found that breast cancer can begin to spread early, even when tumors are small, leaving microscopic traces of the disease after surgery.
The modern approach is to cut out obvious tumors — because lumps big enough to detect may be too dense for drugs and radiation to destroy — and to use radiation and chemotherapy to wipe out microscopic disease in other places.
But doctors have continued to think that even microscopic disease in the lymph nodes should be cut out to improve the odds of survival. And until recently, they counted cancerous lymph nodes to gauge the severity of the disease and choose chemotherapy. But now the number is not so often used to determine drug treatment, doctors say. What matters more is whether the disease has reached any nodes at all. If any are positive, the disease could become deadly. Chemotherapy is recommended, and the drugs are the same, no matter how many nodes are involved.
The new results do not apply to all patients, only to women whose disease and treatment meet the criteria in the study.
The tumors were early, at clinical stage T1 or T2, meaning less than two inches across. Biopsies of one or two armpit nodes had found cancer, but the nodes were not enlarged enough to be felt during an exam, and the cancer had not spread anywhere else. The women had lumpectomies, and most also had radiation to the entire breast, and chemotherapy or hormone-blocking drugs, or both.
The study, at 115 medical centers, included 891 patients. Their median age was in the mid-50s, and they were followed for a median of 6.3 years.
After the initial node biopsy, the women were assigned at random to have 10 or more additional nodes removed, or to leave the nodes alone. In 27 percent of the women who had additional nodes removed, those nodes were cancerous. But over time, the two groups had no difference in survival: more than 90 percent survived at least five years. Recurrence rates in the armpit were also similar, less than 1 percent. If breast cancer is going to recur under the arm, it tends to do so early, so the follow-up period was long enough, the researchers said.
One potential weakness in the study is that there was not complete follow-up information on 166 women, about equal numbers from each group. The researchers said that did not affect the results. A statistician who was not part of the study said the missing information should have been discussed further, but probably did not have an important impact.
It is not known whether the findings also apply to women who do not have radiation and chemotherapy, or to those who have only part of the breast irradiated. Nor is it known whether the findings could be applied to other types of cancer.
The results mean that women like those in the study will still have to have at least one lymph node removed, to look for cancer and decide whether they will need more treatment. But taking out just one or a few nodes should be enough.
Dr. Grant W. Carlson, a professor of surgery at the Winship Cancer Institute at Emory University, and the author of an editorial accompanying the study, said that by routinely taking out many nodes, “I have a feeling we’ve been doing a lot of harm.”
Indeed, women in the study who had the nodes taken out were far more likely (70 percent versus 25 percent) to have complications like infections, abnormal sensations and fluid collecting in the armpit. They were also more likely to have lymphedema.
As the new treatment plans evolve they will become the new Standard of Care. Doctors that ignore the studies and do not follow protocol may face claims for medical malpractice if their departure from the Standard of Care leads to complications.