Advanced oncology practice requires understanding molecular tumor profiling, targeted therapy mechanisms, and immunotherapy principles that have transformed cancer treatment. Targeted therapies exploit specific molecular alterations in cancer cells: tyrosine kinase inhibitors (imatinib for BCR-ABL in CML, erlotinib for EGFR mutations in NSCLC), monoclonal antibodies (trastuzumab targeting HER2 in breast cancer, rituximab targeting CD20 in lymphoma), and PARP inhibitors (olaparib for BRCA-mutated ovarian and breast cancers exploiting synthetic lethality). Immune checkpoint inhibitors (pembrolizumab and nivolumab targeting PD-1, ipilimumab targeting CTLA-4) restore T-cell antitumor immunity by blocking inhibitory signals that tumors exploit to evade immune destruction — immune-related adverse events (irAEs) affecting any organ system require prompt recognition and management with corticosteroids. The clinician must understand tumor mutational burden, microsatellite instability status, and PD-L1 expression as predictive biomarkers for immunotherapy response.