(Reuters Health) - Older women with early-stage breast cancer might be able to skip a lymph node biopsy without changing their survival odds, a small study suggests.
Researchers followed 140 women aged 70 or older who generally had smaller, slow-growing tumors. Even though none of the women got a so-called sentinel node biopsy to see where the tumors might have spread, over the next five years only four of them died of breast cancer.
“For women this age with early breast cancer, a biopsy may not affect the treatment or the outcome,” said senior study author Dr. Armando Giuliano, head of surgical oncology at Samuel Oschin Comprehensive Cancer Institute at Cedars-Sinai Medical Center in Los Angeles.
Worldwide, breast cancer is the most common malignancy in women. About one in nine women will eventually develop it, according to the U.S. National Institutes of Health. The risk increases with age, from 1 in 227 at age 30 to 1 in 26 by age 70.
Over the last decade, sentinel node biopsy has become the most common tool for determining if cancer has spread beyond the initial tumor into the lymph nodes. The procedure involves injecting a dye near the tumor to locate the nodes closest to it, and then removing them to test for cancer. If these nodes are cancer-free, it’s likely that the rest of the lymphatic system will be, too.
Last year, the American Society of Clinical Oncology (ASCO) recommended more women get sentinel node biopsies instead of an older, more invasive procedure known as an axillary lymph node dissection that requires surgeons to remove five to 30 nodes to test for cancer. Giuliano co-chaired the ASCO panel responsible for the new guidelines.
In the current study published in JAMA Surgery, Giuliano and colleagues reviewed data on women who had breast-conserving surgery without a sentinel node biopsy at Cedars-Sinai. None of the women had any obvious lymph node abnormalities show up during exams in the doctor’s office.
Half of the women were at least 83 years old. All of them had tumors that were less than 5 centimeters (2 inches) across, and most had malignancies that were no more than 2 centimeters (3/4 inch).
In addition, 86 percent of the women had what’s known as estrogen-receptor positive breast cancer, a type of slow growing tumor that responds to hormone treatment.
After five years, 70 percent of the women were still alive. Most of the women who died weren’t killed by breast cancer. Instead, the most common cause of death was heart disease.
Because the study only included women who didn’t get a sentinel node biopsy, the results can’t prove that survival odds are just as good as they would be with this diagnostic test.
But the researchers note that 85 percent of women 70 and older with node-negative malignancies die of causes unrelated to breast cancer.
“Older women tend to have (slow-growing) breast cancers and more medical problems than younger women and very often they don’t die of breast cancer,” Giuliano said. “Frequently, they don’t get chemotherapy because they wouldn’t tolerate it, and they are going to get hormone treatment no matter what you find in the biopsy.”
Sentinel node biopsy only needs to be done if it will make a difference in treatment, said Dr. Monica Morrow, chief of the breast service in the surgery department at Memorial Sloan Kettering Cancer Center in New York.
It is standard practice for younger women who are less likely to have small tumors that respond to hormone treatment, said Morrow, who wasn’t involved in the current study. For these women, the test can show whether they would benefit from having all lymph nodes removed or getting chemotherapy or radiation.
For patients who would only get chemotherapy based on cancer in the lymph nodes, the test makes sense, she said in an email. Otherwise, it doesn’t improve survival.
“Twenty years ago, tumor in the nodes was the big determinant of treatment,” Morrow said. “That is no longer true today.”
SOURCE: bit.ly/1d42Mia JAMA Surgery, online May 27, 2015.