Population based study on sentinel node biopsy before or after neoadjuvant chemotherapy in clinically node negative breast cancer patients: Identification rate and influence on axillary treatment

In conclusion, variation exists in the timing of SNB in clinical practice in The Netherlands for clinically node negative breast cancer patients receiving NAC. The post-NAC SN procedure is, despite some lower SN identification rate, associated with a significantly less frequent axillary treatment and thus with less expected morbidity. The effect on recurrence rate is not yet clear. Patients in this registry will be followed prospectively for long-term outcome.