Population-based sentinel lymph node biopsy in early invasive breast cancer

Introduction. Sentinel lymph node biopsy (SLNB) has been proposed as a reliable method for staging of early invasive breast cancer (EIBC). In the present study we analyse the impact of this procedure when systematically applied to all unselected women of a community-based Breast Cancer Unit (BCU). Methods. All consecutive women with unifocal cT1-2 (≤3 cm) cN0 EIBC diagnosed at our BCU were considered for radiocolloid sentinel node localisation and biopsy. Results. Only 387 of all consecutive 542 patients met eligibility criteria for SLNB. Reasons for ineligibility included tumour size, palpable axillary nodes, plurifocality and/or multicentricity, and refusal to undergo the procedure. Successful SLNB was performed in 362 patients (94% of those eligible), but in 108 of these axillary dissection (AD) had to be performed anyway, mainly because of SLN-positivity. Therefore, SLNB ultimately allowed sparing axillary dissection in 256 patients out of the entire population of women with EIBC. Conclusions. Radiocolloid-guided SLNB, when appropriately applied in the context of a population-based service, can help in sparing unnecessary AD, with its related costs and morbidity, in approximately half of all women presenting with EIBC. In absolute terms, in the EU this could result in approximately 100,000 unnecessary AD avoided each year.