Sentinel Lymph Node Biopsy: Actual Topics

The incidence of female breast cancer has increased 0.5% since the year 2000, as reported by the International Agency Research on Cancer. This number is greater in developing countries due to the increase in life expectancy and change in behavior resulting in increased exposure to risk factors. Lymph node staging is an early event carried out during initial patient evaluation in developed countries. Some 20% to 30% of all cases are diagnosed quite early (in situ lesions) DCIS; 79% of the patients diagnosed at stage I and II has negative axillary nodes; (Holland et al., 2001). These values are somewhat different in developing countries where more than 50% of the cases are diagnosed at advanced stages of the disease. Increased survival rates have been reported lately. According to Parkin (Parkin et al., 2001), the overall survival rate is 91% after the first year and 65% after five years in Europe. These values increase to 96.8% after the first year in the United States. As primary prevention of breast cancer is not available as yet, early detection and treatment in the initial phase of the disease are, therefore, the most important measures for its control (INCA, 2009). Available diagnostic methods include mammography, breast ultrasonography and fine-needle aspiration biopsy among others (Moore et al., 1996; Morton et al., 1998). Until 1990, the assessment of axillary status of a patient with breast cancer depended on the histopathologic examination of lymph nodes from complete axillary dissection. With the definition of the sentinel lymph node as the first one which receives the drainage of the tumoral area (Cabanas, 1977), it was possible to ensure means for the proper staging of the illness and the therapeutic approach establishing less invasive surgery techniques. Currently, it is admitted that the presence of metastatic lymph nodes is the main predictor factor for prognosis of the breast malignant neoplasia course and subsequent therapeutic program. Lymph nodes are also valuable for staging breast cancer. In the recent past dissection of the axillary lymph nodes was required for this matter, resulting in a series of additional complications (Veronesi et al., 1999).