Prediction of metastatic axillary in early breast cancer according to the immunohistochemical subtype

Abstract

Objective: The status of axillary involvement is a major prognostic factor in patients with early breast cancer. If we obtain a method to predict the axillary status, with the benefits of the standard approach — axillary dissection and sentinel lymph node biopsy — without its side effects we will hold a major advance in the assessment and treatment of early breast cancer. Methods: We conducted a retrospective cross-sectional study based on records of patients with invasive breast cancer, non metastatic, with any age, treated between 1999 and 2007 in the Hospital das Clínicas, of the Faculty of Medicine, University of Sao Paulo, and Clínical José Aristodemo Pinotti whose histopathological and immunohistochemical studies were supervised by a single pathologist. We performed an immunohistochemical subdivision of the tumors in Luminal A the tumors with hormone receptor positive and HER 2 negative, Luminal B, the hormone-receptor positive and HER 2-positive, HER2 patients with hormone receptor negative and HER 2-positive, and those with triple negative hormone receptors and HER 2 negative. Those subtypes were correlated with predicting the likelihood of axillary lymph node involvement. Results: Two hundred and nine cases were analyzed. In the Luminal A, the possibility of axillary metastasis was higher. That was the only combination that showed statistically significant difference. The patients who had triple-negative tumors had approximately 90% less chance of lymph node metastasis than patients with tumors Luminal A. Conclusion: The patients with Luminal A tumors showed a significantly association with greater likelihood of axillary lymph node metastasis.