Breast Cancer Patients Undergoing Sentinel Node Biopsy: Additional Axillary Tumor Burden as a Function of the Total Number of Excised Sentinel Nodes-A Multicenter Study.

Abstract Background Recent studies have challenged the long-standing assumption that breast cancer prognosis is determined by lymph node regional status. We assessed locoregional relapse, distant metastases, and mortality alongside additional axillary disease in breast cancer patients undergoing sentinel node (SN) biopsy. Patients and Methods This prospective study assessed 1070 women with clinical T1-T2 invasive breast cancer with negative clinical/ultrasound axillae. Results A total of 25.1% of patients had positive SN biopsy findings, of whom 69.2% had only 1 involved SN. The rate of axillary recurrence was 0.7%, with no significant differences found between patients with positive or negative SN (0.6% vs. 1.1%). There were also no significant differences in the rate of distant metastases or breast cancer–specific mortality. If we had applied the Z0011 trial suggestions, residual axillary disease would have reached 16.2%: 13.5% in patients over 50% and 21.3% in patients under 50. The rate of residual axillary disease would have been 25.2% in patients with only 1 SN (20.2% in patients over 50% and 38.2% in patients under 50). In patients with 2 SN, residual disease would have ranged from 12.0% in patients over 50% to 19.0% in patients under 50. From 3 SN on, residual disease seems negligible. Conclusion There were no significant differences in locoregional relapse, distant metastases, or mortality between patients with negative and positive SN. Patients with 3 or more SN have no additional axillary disease. In patients younger 50, one must be extremely cautious if the Z0011 suggestions are to be applied, especially if there is only 1 SN.