[Lymphatic mapping and sentinel lymph node biopsies in order to avoid axilar dissection in early breast cancer]. / Mapeo linfático y linfadenectomía del ganglio centinela para evitar la disección axilar en mujeres con cáncer temprano de mama.

OBJECTIVE: To present the characteristics of women with early breast cancer and clinically negative ganglia who were submitted to LM and SLNB in order to select the positive cases for axilar dissection and to identify the negative cases. MATERIAL AND METHODS: Cases included patients who attended the Breast Tumor Service of the Oncology Hospital of the National Medical Center of the Mexican Social Security Institute from March 1, 2002, to April 30, 2004. Women with early breast cancer and clinically negative ganglia (N0) were included, with out previous treatment and without previous biopsies. All cases were submitted to LM and SLNB with patent blue or double-blue technique and gamma probe. The lymph nodes were evaluated histopathologically and negative or positive results were considered, in order to determine whether or not to undertake the axilar dissection. No cases were excluded. RESULTS: Sixty cases were reviewed with an average age of 51 years. The average size of the ganglia was 1.9 cm, with stages EC-0: 9%, EC-I: 33%, EC-IIA: 58%. Sentinel lymph nodes were found in 100% and 95 ganglions were dissected, for an average of 1.6 per procedure. The histopathology was definitive in 19 women with metastasis (32%) and in 41 women with negative ganglia (68%). The results of transoperative histopathology were correlated with the histopathology report (one false positive and six false negative cases), sensitivity of 68.4%, specificity of 97.5%, positive predictive value 92.8% and negative predictive value 86.9%. CONCLUSIONS: LM and SLNB avoided radical axilar dissection in 68% of the cases and reduced the cost in 10% of the cases.