Identification of sentinel node in breast cancer

Axillary lymphadenectomy is a very important procedure in the staging of breast cancer patients. However, it is associated with a significant morbidity rate. On the other hand, using early diagnosis we can see a high number of cases where the lymph nodes are negatives. With the intention of avoiding unnecessary axillary dissection, the possibility of evaluating a single node has been studied. This lymph node, defined as "sentinel node", would be the first to receive tumoral lymphatic drainage. The aim of this study is to evaluate: (i) the efficacy of the methods to identify the sentinel nodes, (ii) estimate the predictability of the histological examination of the sentinel node in comparison to other nodes of the axilla, (iii) compare the efficacy of the frozen section regarding the definitive histological examination of the same node. This study was performed in 29 patients, and the sentinel node was identified in all of them. It was metastatic in 7 (24.1%). Out of the 22 patients where the node was negative, 15 were submitted to complete dissection. Out of these 15, there was one case (6.7%) where one lymph node of the first level was positive. All 7 patients with the positive sentinel node were submitted to axillary dissection. When comparing the histological examination of the sentinel node with other nodes, we got a sensitivity of 87.5%, specificity of 100%, predictive positive value of 100%, predictive negative value of 93% and efficacy of 95%. The intra-operative examination was made in 24/29 cases (82.7%). The correlation between both examinations was 95.8%. This study shows that the technique of the sentinel node will be a reliable method to avoid radical axillary dissection in breast cancer patients with early diagnosis.