Clinical axillary recurrence after sentinel node biopsy in breast cancer: a follow-up study of 220 patients

Purpose: The aim of this study was to evaluate the frequency of false-negative (FN) sentinel node procedures in patients with breast cancer and the subsequent clinical outcome in such patients.

Methods: A total of 325 breast cancer patients underwent sentinel lymph node biopsy at our institution between June 1998 and May 2004. A 2-day protocol was used to localise the sentinel node with the injection of Tc-99m-nanocolloid. There were two phases in the study: the learning phase (105 patients) and the application phase (220 patients). In the learning phase, a complete lymphadenectomy was always performed. In the application phase, sentinel nodes were studied intraoperatively and lymphadenectomy was performed when considered warranted by the pathological intraoperative results.

Results: The median follow-up duration in the 220 patients studied during the application phase was 21.2 months (range 4-45 months). In this phase a total of 427 sentinel nodes were obtained (range 1-5 per patient, median 1.99), with 66 positive sentinel nodes in 56 patients (26%). The lymphadenectomies performed were also positive in 25% of cases (14 patients). We observed a total of two false-negative sentinel lymph node results (3.45%). One of them was found during the surgical excision of non-sentinel nodes, and the other presented as an axillary recurrence 17 months postoperatively (1.72% clinical false-negative rate). The latter patient died 1 year after the first recurrence.

Conclusion: After a median follow-up of 21.2 months we observed only one clinical recurrence among 220 patients. Our results indicate that adequate local control is achieved by application of the sentinel node protocol.