In what many believe to be a discovery that will reverse standard medical practice in the months and years to come, a recent study found that 20% of women being treated for early-stage breast cancer received no benefit from surgical removal of cancerous lymph nodes.
The study, funded by the National Cancer Institute and published earlier this year in the Journal of the American Medical Association (JAMA), examined data collected from nearly 900 women treated at 115 sites across the country and found no significant difference in five-year survival rates between 445 women who had lymph nodes removed and 446 women who did not. Among women who had nodes removed, the five-year disease-free survival rate was 83.9% compared with 82.2% among women who did not have nodes removed. The average age of women in the study was 50. They had stage T1 and T2 tumors with cancerous nodes too small to be felt and cancer that had not spread. All of the women received chemotherapy and radiation.
Until now, when cancer reaches the lymph nodes (as it does in roughly one third of the 200,000 cases of breast cancer diagnosed each year in the U. S.), doctors recommend lumpectomies, removing the breast tumor along with the lymph nodes to reduce the risk of recurrence. But the surgery is often painful and can lead to infection and other complications, including lymphedema. Usually one or two sentinel nodes are removed, leaving the other nodes if the sentinel nodes are cancer-free. Additional nodes are removed only if the sentinel nodes are cancerous. But based on these new findings, this study suggests that, even if cancer is present in the sentinel nodes, removing additional nodes is not necessary.
The findings may not apply to women who have three or more affected lymph nodes, larger tumors, or women who have had mastectomies. Researchers also noted that the current study tracked the participants over only six years. It is unclear how these women will do in the long term.
Nevertheless, the American Society of Clinical Oncology (ASCO) believes that findings from the study will likely lead to a significant change in recommendations for treating women with breast cancer who are similar to those in the study.
According to other experts, this latest study represents an important development and confirms the benefit of moving toward less aggressive treatment options that allow women to avoid additional surgery and potential complications.