Sentinel lymph node identification in breast cancer patients

Purpose. To evaluate the predictive value of sentinel lymph node biopsy versus axillary node dissection on lymph node status in patients with T1-T2 breast cancer. Material and methods. Twentynine patients with T1 and 12 with T2 breast carcinoma and clinically NO axillary lymph nodes, underwent lymphoscintigraphy following the administration of 99mTc-human albumin nanocolloids. The tracer was injected subdermally, over the tumor mass, in the 34 patients with palpable lesions and peritumorally (n=3) or intratumorally (n=4), under stereotactic or ultrasound guidance, in the 7 patients with non-palpable lesions. Anterior and lateral planar images were acquired 15 min after the injection of the tracer and repeated every 30 min up to 3 hr until identification of sentinel lymph node. At the end of the scintigraphic study, sentinel node skin projection was marked using a demographic pen. Eighteen hours after lymphoscintigraphy, sentinel lymph node was identified and removed during surgery by hand-held gamma probe, then, the remaining axillary lymph nodes were dissected. All surgical specimens underwent histologic examination. Sentinel lymph nodes free of metastasis at histology, underwent additional examination with immunohistochemistry using monoclonal antibodies against cytokeratin and EMA to search for micrometastases. Results. Sentinel lymph node was identified in the 34 patients injected subdermally and in the 3 patients injected peritumorally, while it remained undetected in the 4 patients injected intratumorally except for one case in which it was isolated by radioguided surgery but not scintigraphically. Sentinel nodes resulted free of metastases both at histology and immunohistochemistry in 32 cases and metastatic in 6. In the 32 patients with non-metastatic sentinel lymph nodes the other axillary nodes were also free of metastases. Among the 6 metastatic sentinel lymph nodes, in 3 cases they were the only metastatic nodes of the axilla while in the other 3 cases metastases were spread to other axillary nodes. Conclusions. In agreement with previous studies, our results showed that sentinel lymph node radioguided biopsy is a simple and reliable method for predicting axillary lymph nodes status and for avoiding axillary dissection in early breast cancer patients with sentinel node free of metastases.