Systemic Therapy Management Strategies for Early-Stage Breast Cancer in Australia

Breast cancer is the most common cancer among Australian women, with early-stage disease (Stages I, II, and III) representing the majority of cases. Advances in screening, diagnosis, and systemic therapies, including chemotherapy, endocrine therapy, targeted agents, and immunotherapy, have markedly improved survival rates. This review synthesizes recent developments in systemic therapy for early breast cancer, with a focus on Australian data and practice patterns. We explore subtype-specific management strategies for estrogen receptor-positive (ER+)/HER2-negative, HER2-positive, and triple-negative breast cancer (TNBC). For ER+/HER2- early breast cancer, the utility of genomic assays such as Oncotype DX, PAM50, and MammaPrint is discussed, with a focus on chemotherapy selection and the role of CDK4/6 inhibitors, and the role of extended endocrine therapy and adjuvant zoledronic acid. In HER2-positive breast cancer, we examine neoadjuvant therapy with dual HER2 blockade (trastuzumab and pertuzumab), personalized regimens that minimize cardiotoxicity, and the potential of antibody-drug conjugates. For TNBC, the growing role of immunotherapy, dose-dense regimens, and adjuvant capecitabine is reviewed, with a focus on olaparib in BRCA-mutated cases. This review also addresses special populations, including BRCA mutation carriers and premenopausal women, and looks at future trends in systemic therapy, including novel agents, biomarker-driven approaches, and treatment de-escalation strategies.