Older women with very early, non-invasive “stage 0” breast cancer gain no long-term benefit from undergoing a sentinel lymph node biopsy to see if the cancer has spread, new research shows.
The study, believed to be the first to examine the long-term impact of sentinel lymph node biopsies on thousands of older women with ductal carcinoma in situ (DCIS), found that the procedure:
- Does not reduce the likelihood of dying from breast cancer
- Does not decrease the chances of developing invasive breast cancer
- Does not decrease the number of additional cancer treatments
However, the findings show the procedure does increase the patient’s risk for side-effects associated with the biopsy, which include pain, wound infection, and lymphedema, a painful condition that can restrict a woman’s arm movements.
Earliest form of breast cancer
The findings are important because between 17% and 40% of women with DCIS currently undergo sentinel lymph node biopsies, even though experts don’t recommend the procedure for these patients, says Shi-Yi Wang, associate professor in the Yale School of Public Health lead author of the paper, published in JNCI Cancer Spectrum.
Approximately 25% of all breast cancer patients have DCIS, the earliest form of breast cancer, in which cancer cells invade the milk duct in the breast.
Known as a “stage zero” breast cancer, DCIS is not life-threatening because it is non-invasive, meaning the cancer cells do not spread beyond the milk duct. If untreated, however, DCIS can develop into an invasive type of breast cancer.
“More is not better. More is just more, and in this case, more is worse.”
Women diagnosed with DCIS almost always have surgery (usually a lumpectomy) to remove the DCIS and not the entire breast. Many also have the sentinel node biopsy, which involves removing a few lymph nodes under the arm to determine if the cancer has spread. Since DCIS is not invasive, experts don’t recommend these biopsies for DCIS patients.
So why do so many women undergo sentinel lymph node biopsies?
“Proponents of sentinel lymph node biopsy cite concerns that occult microinvasive disease within the DCIS may not be detected via other methods. Also, the sentinel lymph node biopsy is included in the Centers for Medicare & Medicaid merit-based incentive payment system for invasive breast cancer,” Wang says. “This might create a financial incentive for providers to perform these biopsies even for non-invasive conditions.”
What about young women?
Wang’s study compared the health outcomes of 5,957 women who had undergone a lumpectomy to remove DCIS, including 1,992 who had undergone a sentinel lymph node biopsy, with 3,965 women who did not have the biopsy procedure. Doctors followed the women, all between the ages of 67 and 94, for a median of 5.75 years after their initial lumpectomy.
Wang cautions that the findings may not apply to young women and that more research is also needed to determine if sentinel lymph node biopsies benefit patients with a high-risk type of DCIS.
The findings have important implications for women with breast cancer, says Laura Esserman, professor of surgery and radiology at the University of California-San Francisco and director of their Breast Care Clinic, who was not involved in the study.
“Some surgeons say that sentinel node biopsies are no big deal, but I disagree. All interventions have consequences,” she says. “More is not better. More is just more, and in this case, more is worse.”
The Patient-Centered Outcomes Research Institute funded the work.
Source: Yale University