Accuracy and reliability of sentinel node biopsy in patients with breast cancer. Single centre study with long term follow-up.

The aim of our study is to evaluate the frequency of false-negative (FN) sentinel node procedures in patients with breast cancer. A total of 791 breast cancer patients underwent sentinel lymph node (SLN) biopsy at our institution between July 1997 and February 2005. A 2-day protocol was used to localise the sentinel node with the injection of 99mTc-nanocolloid. There were two phases in the study: the learning phase (50 patients) and the application phase (741 patients). In the learning phase, a complete lymphadenectomy was always performed. In the application phase, sentinel nodes were studied postoperatively with breast cancer and lymphadenectomy was performed when considered warranted by the pathological postoperative results. The median follow-up duration in the 741 patients studied during the application phase was 32.3 months (range 6-72 months). In this phase a total of 787 sentinel nodes (719 axillary and 68 intramammary chain) were obtained (range 0-5 per patient, mean 1.01), with 153 (41 with micrometastasis) positive sentinel nodes. We observed a total of three FN SLN results (0.5%). All three presented as an axillary recurrence into 24 months from operation. After a median follow-up of 32.3 months we observed only three clinical recurrences among 741 patients. Our results indicate that the sentinel node protocol can give an adequate local control.