Identification and biopsy of the sentinel lymph node in breast cancer

Aims: To examine the hypothesis that lymphatic dissemination in breast cancer occurs sequentially. Methods: Thirty patients with clinically localized adenocarcinoma were studied. Patent blue dye was administered into the tumour at the beginning of a modified radical mastectomy or segmental mastectomy with en bloc axillary lymph-node dissection (ALND). In the removed specimen, blue-stained lymphatic channels were dissected from the primary tumour to the first draining lymph node(s) (sentinel node(s)). Results: Identification of a sentinel node (SN) was successful in 26 patients (87%). In 10 patients the SN was tumour-positive. In six of these patients, the SN was the only tumour-positive node. There was no incidence of ‘skip’ metastasis. Conclusions: This study confirms the sequential nature of lymphatic dissemination. When confirmed in vivo, these data may lead to a substantial reduction of the need for ALND without compromising survival and regional control and without loss of prognostic and staging information.