Clinical investigation: Regional nodal failure patterns in breast cancer patients treated with mastectomy without radiotherapy

Conclusions: These results suggest that failure in the level I-II axilla is an uncommon occurrence after modified radical mastectomy and chemotherapy. Therefore, supplemental radiotherapy to the dissected axilla is not warranted for most patients. However, patients with ≥4 involved axillary lymph nodes, >20% involved axillary nodes, or gross extranodal extension are at increased risk of failure in the supraclavicular fossa/axillary apex and should receive radiation to undissected regions in addition to the chest wall.