Top Line: The indications for axillary dissection for breast cancer when radiation is planned are diminishingly small.
The Study: Here is an informative Dutch prospective study that enrolled 350 women with cN1 breast cancer per pre-treatment PET. The largest node was biopsy-confirmed and marked with a radioactive seed prior to neoadjuvant systemic therapy. Here’s where things get interesting: at the time of breast surgery, only the marked node was removed regardless of whether it harbored residual nodal disease. Those with ypN0 disease (n=135) proceeded to whole breast radiation alone following breast-conserving surgery or no radiation following mastectomy. Those with ypN1 disease (n=215) proceeded to regional nodal irradiation to include the whole breast or chest wall. At a median follow-up just over 4 years, there was 1 (0.7%) axillary recurrence in the ypN0 cohort and 7 (2.3%) in the ypN1 cohort. Disease-free survival was 93% and 87%, respectively. Of course, this doesn’t tell us what benefit completion dissection would have offered the ypN1 cohort, but not many women would sign-up for one to lower the risk below 2%. An accompanying editorial highlights size may be an indicator of who stands to benefit from more extensive surgery: “None of 18 patients with isolated tumor cells had a local-regional recurrence compared to 1 of 30 patients (3%) with micrometastases and 8 of 167 patients (5%) of those with macrometastases.”
TBL: A clear therapeutic role for completion axillary dissection of microscopic disease when radiation is planned remains to be clarified. | van Hemert, JAMA Oncol 2025
The Study: Here is an informative Dutch prospective study that enrolled 350 women with cN1 breast cancer per pre-treatment PET. The largest node was biopsy-confirmed and marked with a radioactive seed prior to neoadjuvant systemic therapy. Here’s where things get interesting: at the time of breast surgery, only the marked node was removed regardless of whether it harbored residual nodal disease. Those with ypN0 disease (n=135) proceeded to whole breast radiation alone following breast-conserving surgery or no radiation following mastectomy. Those with ypN1 disease (n=215) proceeded to regional nodal irradiation to include the whole breast or chest wall. At a median follow-up just over 4 years, there was 1 (0.7%) axillary recurrence in the ypN0 cohort and 7 (2.3%) in the ypN1 cohort. Disease-free survival was 93% and 87%, respectively. Of course, this doesn’t tell us what benefit completion dissection would have offered the ypN1 cohort, but not many women would sign-up for one to lower the risk below 2%. An accompanying editorial highlights size may be an indicator of who stands to benefit from more extensive surgery: “None of 18 patients with isolated tumor cells had a local-regional recurrence compared to 1 of 30 patients (3%) with micrometastases and 8 of 167 patients (5%) of those with macrometastases.”
TBL: A clear therapeutic role for completion axillary dissection of microscopic disease when radiation is planned remains to be clarified. | van Hemert, JAMA Oncol 2025