Context: Quantum Software Engineering (QSE) has emerged as a promising discipline to support the development of quantum applications by integrating quantum computing principles with established software engineering practices. Problem: Despite recent growth, QSE still lacks standardized methodologies, tools, and guidelines. Moreover, countries like Brazil have had minimal representation in the development of this emerging field. Objective: This study aims to map the current state of QSE by identifying research trends, contributions, and gaps that can inform future investigations and strategic initiatives. Methodology: A systematic mapping study was conducted across major scientific databases, retrieving 3,219 studies. After applying inclusion and exclusion criteria, 3,052 studies were excluded, resulting in 167 selected for analysis. The publications were classified by study type, research type, and alignment with SWEBOK knowledge areas. Results: Most studies focused on Software Engineering Models and Methods, Software Architecture, and Software Testing. Conceptual and technical proposals were predominant, while empirical validations remained limited. Conclusions: QSE is still a maturing field. Advancing it requires standardization, more empirical research, and greater participation from developing countries. As its main contribution, this study proposes a Brazilian Research Agenda in QSE to guide national efforts and foster the development of a strong local scientific community.