A recent trial involving women from five countries, led by researchers at Karolinska Institutet and published in the New England Journal of Medicine, has shown that it is possible to avoid removing most of the lymph nodes in the armpit, even if one or two of them have metastases larger than two millimeters. This discovery could lead to less invasive surgery for breast cancer patients. . The results open up for gentler surgery rnrn
When it comes to breast cancer, the spread of the disease to the lymph nodes in the armpit is a concern for patients. However, if the tumors are only found in the breast and armpit lymph nodes, it is considered a localized disease with the goal of curing the patient.
One challenging decision for breast cancer surgeons is what to do when patients have metastases in the armpit, which are first detected during surgery. The removal of many lymph nodes in the armpit, known as axillary dissection, increases the risk of arm lymphedema. This condition occurs when lymph fluid is unable to flow as freely as before.
Swelling in the arm can result in pain and restricted mobility.
Jana de Boniface, a breast cancer surgeon at Capio S:t Görans’s Hospital and researcher at the Department of Molecular Medicine and Surgery at Karolinska Institutet, emphasizes the importance of performing less extensive procedures to minimize troublesome side effects while ensuring safety.
If metastases are known to be present in the armpit before breast cancer surgery, different treatment paths are chosen, and these patients are not included in this trial. However, The sentinel lymph nodes, which are the first nodes reached by lymph fluid from the breast, are surgically removed. If they contain single tumor cells or metastases that are no larger than two millimeters, the rest of the lymph nodes in the armpit are left untouched. Previous studies have demonstrated that this approach is safe for patients.
A new large-scale study led by Karolinska Institutet has provided further clarity on the matter, even for larger metastases. The study involved nearly 2,800 patients from five different countries, all of whom had macrometastases (metastases larger than two millimeters) in one or two sentinel lymph nodes.
Following the sentinel node surgery, the researchers found that the patients had a low risk of the cancer spreading to the rest of the lymph nodes in the armpit. This suggests that leaving the remaining lymph nodes intact in such cases is also safe for patients, as it minimizes the risk of unnecessary surgical removal.The patients were divided into two groups: one group underwent a completion axillary dissection, which was previously standard practice for all patients, and the other group left the rest of the armpit undisturbed. Almost all patients received postoperative treatment with chemotherapy and/or anti-hormonal therapy, as well as radiation therapy based on guidelines in each country. Over one-third of patients who had axillary dissection were found to have more metastases than the maximum two in the sentinel lymph nodes. It can be assumed that the same is true for those who left the remaining lymph nodes. However, recurrences were equally common in both groups.
Postoperative treatment appears to be effective in eliminating any remaining tumor cells.
A previous study from the trial found that 13% of patients who underwent axillary dissection experienced significant arm function issues, compared to only 4% of those who had the sentinel lymph nodes removed.
The findings suggest that it is safe for patients with a maximum of two macrometastases in the sentinel lymph nodes to skip axillary dissection. In these cases, radiation therapy to the armpit is used as an alternative, resulting in fewer arm-related complications.
The implementation of the trial called SENOMAC in Sweden has led to significant improvements in clinical practice, according to Jana de Boniface. The trial has been funded by grants from the Swedish Research Council, the Swedish Cancer Society, the Nordic Cancer Union, and the Swedish Breast Cancer Association.
