The influence of the extended indications for sentinel node biopsy on the identification of metastasis-free and metastatic sentinel nodes

Abstract

Background and objective: Rates of sentinel node (SN) identification and metastasis-positive SNs were compared between the group with highly selective indications for sentinel node biopsy (SNB) and the group with merely no contraindications for SNB (Groups A and B, respectively).

Materials and methods: We performed a single-center retrospective data analysis of 471 breast cancer patients treated during 2004-2010. Data on clinical and pathologic staging, frozen section results, radiological measurements and pathologic examination results were obtained from patient records. Patients were analyzed in two groups. Group A (n=143) had SNB performed only when the patients fulfilled to the following criteria: breast tumor no greater than 3cm in diameter, unifocal disease, no pure ductal carcinoma in situ, no history of previous breast or lymph node surgery, and no neoadjuvant chemotherapy. Indications for SNB were extended in Group B (n=328) so that inflammatory breast cancer and positive lymph nodes became the only exclusion criteria.

Results: The rate of SN identification was 97.9% in Group A vs. 99.09% in Group B (P=0.29). SNs were metastasis positive and frozen sections false negative at comparable proportions in both groups.

Conclusions: The extension of indications for SNB did not reduce the rates of SN identification or did not create any impact on the rate of metastatic SNs.

Keywords: False negative rate; Identification rate; Metastatic sentinel node rate; Sentinel node biopsy.