Sentinel lymph node biopsy experience in Taranaki: a prospective audit in a provincial New Zealand hospital.

Aim Sentinel lymph node biopsy has been rapidly incorporated into the management of early stage invasive breast cancer. The aim of this study was to review the adoption of sentinel lymph node biopsy at a provincial centre in New Zealand and compare markers of performance against established standards. Methods The Taranaki Breast Database was created in 2002 and prospectively records data from all breast cancer patients in the Taranaki area. Data on all patients undergoing sentinel lymph node biopsy were retrieved and the results reviewed. Results Between October 2002 and August 2007, 152 sentinel lymph node biopsies were undertaken in 151 patients. The initial 49 patients (training set) also underwent routine axillary clearance as part of an initial audit on the accuracy of sentinel lymph node biopsy. A sentinel node was identified in 97% of patients (93% including the training set) and a mean of two nodes per biopsy were removed. Metastatic nodal disease was identified in 40 of 152 (26%) of biopsies of which nine were micrometastases. In the training set there was a false negative rate for nodal spread of 5% (two of 40) and a 92% negative predictive value. Conclusions The performance of sentinel lymph node biopsy in Taranaki is comparable to international centres. Adoption of this technique as routine may spare many Taranaki women the morbidity of axillary clearance, without jeopardising safety. Axillary lymph node status is considered the most important prognostic factor for patients with early stage breast cancer. 1 While axillary clearance is accepted as the gold standard in detection of metastatic nodal disease, sentinel lymph node biopsy (SLNB) is increasingly adopted as an alternative approach. Early research suggests that SLNB is a reliable method of predicting lymph node status, and may spare women the morbidity associated with axillary clearance. 2,3 Nonrandomised studies of SLNB followed by axillary clearance have demonstrated that one or more sentinel lymph node can be identified in more than 90% of patients with invasive breast cancer, with a false negative rate of less than 10%. 4,5 In an era of increasing centralisation of surgical services, little published data exists on adoption of SLNB in peripheral centres. In Taranaki, a provincial New Zealand centre, SLNB techniques have been employed since 2002. This study aims to provide a prospective comparison of SLNB in Taranaki with established standards.