Sentinel Node Biopsy Before and/or After Neoadjuvant Chemotherapy in Breast Cancer

Sentinel lymph node biopsy (SLNB) was introduced in the late 1990´s and has become standard procedure for staging of the axilla in early stage breast cancer associated with significantly less arm morbidity than axillary lymph node dissection (ALND).

Neoadjuvant chemotherapy (NAC) given before breast surgery is indicated for locally advanced breast cancer but is increasingly used for early stage breast cancer with the purpose of downstaging the tumor and thereby possibly enabling breast conserving surgery. Traditionally, the standard axillary staging tool has been ALND although up to 50 per cent of the patients at diagnosis do not have any metastases in their axillary lymph nodes. In addition, NAC can eradicate metastases in the axillary lymph nodes in up to 40 per cent of the patients.

SLNB has therefore been evaluated in the neoadjuvant setting both before and after NAC but is still controversial and the timing debated.

This is a Swedish prospective multi-institutional study without any comparison goup. The comparison is between the findings in the SLNB and the following ALND performed after NAC in all patients.

If the patient is clinically node-negative at diagnosis a SLNB is performed before (without frozen section) and after NAC (substudy I). The reasons for repeating SLNB both before and after NAC are 1) to find out what happens during NAC 2) if it is possible to identify a repeat SLNB and 3) if it is reliable.