Lais A. Inaba, Fábio F. O. Rodrigues, Rodrigo M. Silva, Christine M. Ferreira, Walda H. Coelho, Mauricio Fristachi, Carlos E. Fristachi

“Objective: This study aimed to identify the effect of breast cancer subtype (Luminal, Luminal-Her 2+, Her 2+, triple negative – TNBC) on axillary lymph node metastasis in breast cancer. Methods: A retrospective study with patients who underwent axillary lymph node dissection (ALND) with primary breast cancer at Department of Mastology and Gynecologic Oncology of ICAVC. The patients were subdivided according to the immunophenotypic profile and than evaluated as the number of positive lymph node obtained from ALND. The patients were classified into three distinct groups based on the axillary lymph status: no lymph node involvement, 1-3 lymph node affected, more than 3 lymph node affected.Results: A total of 84 patientes were retrospectively evaluated between 2008 – 2009 at Department of Mastology and Gynecologic Oncology of ICAVC, and there were 61 patients who underwent ALND. Thirty-five (57,37%) patients had axillary lymph node metastasis: Luminal-Her 2 + (n=9), Her-2 overexpression (n=9) and triple negative (n=11) patientes were associated with higher rates of lymph node involvement (77,7%, 77,7% e 81,8% respectively). In the group which does not have lymph node metastasis predominated patients with subtype Luminal (n=32), with positive result in 37,5% of the cases. Conclusion: Although the study limitations, it was possible to evaluated that the breast cancer subtype is an independent factor to predict the risk of axillary lymph node metastasis in patients with breast cancer. These findings suggest that TNBC and Her 2 overexpression are more related to lymph node metastasis compared to patients with other breast cancer subtype. Key-word : breast cancer, lymph node metastasis, breast cancer subtype, molecular subtypes”