Less surgery for some breast cancer patients with minimal spread to lymph nodes
CANCER DIGEST – April 14, 2024 – A Swedish study shows that when breast cancer that has spread only tiny tumor cells to the sentinel lymph nodes in the armpit, the remaining lymph nodes may be safely left in place.
The large study of 2,766 women with early stage breast cancer in five countries showed that after nearly four years of follow up, the 1,355 women who only had the sentinel lymph node removed had about the same recurrence free survival as the 1,205 women who had more extensive lymph node removal. The study was published in the April 3, 2024 New England Journal of Medicine.
The results open the possibility of less extensive surgery for breast cancer that could spare many of the complication of lymphedema, which results in swelling and sometimes pain and loss of range of motion in the arms. Currently, if cancer is found in the sentinel lymph nodes, the lymph gland first reached by lymph fluid from the breast, then the surgeon performs an axillary dissection, or removal of the remaining lymph nodes in the armpit.
"We want to perform less extensive procedures to spare patients from troublesome side effects," Jana de Boniface, breast cancer surgeon and researcher at the Karolinska Institutet in Sweden said in a press release. "But we need to know that it's safe."
In the trial all the participants, in addition to surgery to remove the breast tumor, had surgery to remove one or two sentinel lymph nodes. Those lymph nodes with metastasized tumors larger than two millimeters, about the size of the tip of a ballpoint pen, were randomly assigned to undergo complete removal of remaining lymph nodes, or leave the rest of the lymph nodes in the armpit.
Nearly all patients underwent additional chemotherapy or anti-hormonal therapy plus radiation according to current guidelines.
More than a third of the patients who had all the remaining lymph nodes removed were found to have cancer in lymph nodes beyond the sentinel lymph nodes. Logically there must have also been tumors beyond the sentinel lymph nodes in the women who did not undergo the more extensive surgery.
Despite this, recurrence of cancer was about the same in both groups, indicating that post operative chemo or hormone therapy was sufficient to eliminate any remaining tumors in the lymph system.
The authors of the study concluded that it is safe for patients with only one or two small metastasized tumors in the sentinel lymph nodes to forgo axillary dissection, or removal of all the remaining lymph nodes in the armpit.
Source: Karolinska Institute press release and New England Journal of Medicine
