Contemporary oncology is increasingly characterized by prolonged survival, treatment complexity, and the consequent transformation of cancer into a chronic or long-term condition. These developments have produced significant clinical benefits, but they have also increased organizational and care multidimensionality, with pathways that are often fragmented and variable across different settings. In this context, nursing assumes a transversal role, coordination, and coherence within multidisciplinary oncology pathways. Advanced nursing roles—including Case Manager Nurses, Nurse Navigators, and Oncology Specialist Nurses—facilitate coordination, support clinical decision-making, promote patient empowerment and therapeutic education, while simultaneously reducing the organizational and cognitive burden on patients, families, and their communities. The integration of digital tools, hybrid care models, and community-based interventions further strengthens nurses’ capacity to ensure quality, adherence, and safety of care. The heterogeneity of care models reflects the elaboration of real-world oncology, but it may compromise effectiveness if not guided by evidence-based practices. Nurses, thanks to their longitudinal and systemic perspective, act as regulators of complexity, translating evidence into context-adapted pathways while maintaining high standards of quality. Recognition and institutionalization of advanced nursing competencies are therefore essential to ensure coherent, equitable, and sustainable oncology care globally.