Molecular Oncogenetics: Somatic Mutations, Tumour Heterogeneity, and Targeted Therapies

Cancer is fundamentally a disease of the genome, and this chapter offers a rigorous review of the somatic mutational landscape of human malignancies — including driver mutations, structural rearrangements, and copy number alterations — as revealed by large-scale sequencing initiatives. It examines the molecular basis of tumour heterogeneity, clonal evolution, and therapy resistance, and reviews the principles and recent advances of molecularly targeted therapies and immune checkpoint blockade. Liquid biopsy and circulating tumour DNA as tools for real-time tumour monitoring are also discussed.