Análise da expressão de rank/rankl no câncer de mama: revisão sistemática da literatura

Abstract

Introduction: Breast cancer is the most frequent cause of death from cancer in the female population worldwide, and the presence of distant metastasis has a great impact on patient survival, especially bone metastases. The RANK/RANKL/OPG system is involved in the maintenance of bone homeostasis and in the development of the mammary gland, however, the prognostic potential of the expression of these biomarkers in breast cancer is still discussed. Objective: To investigate, through a systematic review of the literature, the association between the expression of RANK and/or RANKL and the prognosis of patients with breast cancer. Methodology: This systematic literature review was based on the methodological guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The study was registered in PROSPERO (International Prospective Systematic Reviews Registry) and the guiding question of the study was established through the PICO strategy, that is, Population, Intervention/Exposure, Comparison and “Outcome”. We included studies that evaluated the expression of RANK and/or RANKL, through immunohistochemistry, in relation to clinicopathological and prognostic variables of breast cancer. Results: Eight studies that met the proposed criteria were included, totaling a sample of 1,876 patients. Six of the eight studies demonstrated associations between RANK expression and prognostic determinants of breast cancer, confirming the importance of the biomarker in this assessment. RANK overexpression was associated with more aggressive tumors, with metastatic potential, with the development of bone metastases and, mainly, with worse survival. Conclusion: The studies included in this review confirm the importance of RANK biomarker prognosis in the evaluation of patients with breast cancer, reaffirming the need for more robust studies for the proper use of therapeutic and preventive protocols that use this biomarker as a therapeutic target.