É possível evitar a biópsia do linfonodo sentinela em pacientes portadoras de câncer de mama e linfonodo axilar positivo com resposta patologica completa à quimioterapia neadjuvante?

Abstract

Breast cancer is the leading cause of cancer-related death in women. Radical surgery, for a long time, represented the only form of therapeutic approach. In recent decades, there has been an advance in the treatment of breast cancer, especially with the advent of neoadjuvant chemotherapy, making it surgically less aggressive, maintaining therapeutic efficacy and causing fewer sequelae. Like the primary breast tumor, neoplastic axillary involvement may also respond to neoadjuvant chemotherapy. We tried to identify factors related to the pathological complete response in the breast and armpit to be considered when evaluating the possibility of sentinel lymph node negation in patients with clinically positive axillae prior to neoadjuvant treatment. Objective: To analyze the possibility of avoiding sentinel lymph node biopsy in patients with breast cancer undergoing neoadjuvant chemotherapy, who present a complete pathological response in the primary tumor, treated in a reference institution in Northeastern Brazil. Prospective, observational, cohort study in patients with breast cancer undergoing neoadjuvant chemotherapy and operated on at the Haroldo Juaçaba Hospital, from March 2019 to July 2020. Results: 45 patients were included in the study, with average age of 52 .6 years, all female. After neoadjuvant chemotherapy, 9 (21.4%) patients had a complete pathological response in the breast and 17 (40.5%), a complete pathological response in the lymph nodes. Patients with complete breast response had a 20.44-fold higher prevalence of complete lymph node response than patients who did not have the same response. HER2 positive patients had a 17.73-fold higher prevalence of objective lymph node response than HER2 negative patients. The absence of RE indicated a prevalence of objective lymph node response 4.36 times higher than in patients with the expression of this receptor. Conclusion: In our study, complete pathological breast response to neoadjuvant chemotherapy was a strong predictor of pathological response in axillary lymph nodes. Positivity for HER2 protein and negativity for ER were factors that inferred a good response of axillary metastatic involvement by breast cancer, suggesting that, fulfilling these criteria in specific patients, sentinel lymph node biopsy could be avoided without harming the local control of the breast cancer.