Oncological outcomes of omitting axillary lymph node dissection in breast cancer patients with sentinel lymph node micrometastasis undergoing mastectomy without radiotherapy.

PURPOSE: To evaluate the oncological outcomes of breast cancer patients with sentinel lymph node (SLN) micrometastases, who underwent mastectomy without axillary lymph node dissection (ALND) or post-mastectomy radiotherapy (PMRT).

METHODS

This retrospective single-center study included 79 breast cancer patients with SLN micrometastases who underwent mastectomy, but not completion ALND or PMRT, between 2007 and 2020. We reviewed clinicopathological characteristics, adjuvant systemic therapies, and oncological outcomes. The primary outcome was loco-regional recurrence-free survival (LRFS), and the secondary outcomes included distant disease-free survival (DDFS) and breast cancer-specific survival (BCSS).

RESULTS

The median age at surgery was 56 years. Most tumors (79%) were estrogen receptor-positive/human epidermal growth factor receptor 2-negative, and approximately 49% were classified as cT1. The median number of removed SLNs was two, and the median number of positive nodes was one. After a median follow-up of 4.8 years, the estimated 5-year LRFS, DDFS, and BCSS were 97.1%, 94.6%, and 95.5%, respectively.

CONCLUSION

Low rates of loco-regional recurrence were observed in this retrospective cohort of breast cancer patients with SLN micrometastases, who underwent mastectomy without ALND or PMRT.