Reevaluating Axillary Lymph Node Dissection in Total Mastectomy for Low Axillary Burden Breast Cancer: Insights from a Meta-Analysis including the SINODAR-ONE Trial

Simple Summary In the past, breast cancer patients with lymph node involvement often had surgery to remove most or all of the lymph nodes in the armpit, which can cause significant side effects. However, recent research, like the ACOSOG Z0011 study, has shown that for patients with only a few affected lymph nodes who are getting breast-conserving treatment and radiation treatment, this extensive surgery might not be necessary and doesn't affect their chances of survival. This study looked at whether the same applies to patients having a total mastectomy. We analyzed several studies involving over 4000 patients and found that skipping the extensive lymph node surgery didn't impact overall survival after about 7 years of follow-up. This suggests that certain breast cancer patients having mastectomy with limited lymph node involvement, can safely avoid the more invasive surgery for the lymph nodes in armpit. However, more research is needed to fully understand how other factors might affect survival.Abstract Complete axillary lymph node dissection (cALND) was previously the standard of care for breast cancer (BC) patients with axillary node disease or macro-metastases found via sentinel lymph node biopsy (SLNB). However, due to significant morbidity, contemporary management now considers a more selective approach, influenced by studies like ACOSOG Z0011. This trial showed that cALND could be omitted without compromising local control or survival in patients with low axillary nodal disease burden undergoing breast-conserving therapy, radiotherapy, and systemic therapy. The relevance of this approach for women with low axillary nodal burden undergoing total mastectomy (TM) remained unclear. A PubMed search up to September 2023 identified 147 relevant studies, with 6 meeting the inclusion criteria, involving 4184 patients with BC and low-volume axillary disease (1-3 positive lymph nodes) undergoing TM. Postmastectomy radiotherapy receipt was similar in both groups. After a mean 7.2-year follow-up, both the pooled results and the meta-analysis revealed no significant differences in overall survival. The combined analysis of the published studies, including the subgroup analysis of the SINODAR-One trial, indicates no survival advantage for cALND over SLNB in T1-T2 breast cancer patients with 1-3 positive sentinel lymph nodes (pN1) undergoing mastectomy. This suggests that, following a multidisciplinary evaluation, cALND can be safely omitted. However, the impact of other patient, tumor, and treatment factors on survival requires consideration and therefore further prospective trials are needed for conclusive validation.