The Pathogenesis of Epithelial Ovarian Cancer

Epithelial ovarian cancer is not a single disease but a group of biologically distinct malignancies that include serous (high-grade and low-grade), endometrioid, clear cell, and mucinous carcinomas, along with other rare subtypes. Integrating clinicopathological analyses, genomic and multiomic data, and experimental investigations in model systems has revealed the pathogenesis of the various histologic subtypes. A unique feature of epithelial ovarian cancer is that most of these tumors are now recognized to arise not from ovarian tissue but from the fallopian tube or endometrium, the latter in the context of ovarian endometriosis. Studies of precursor lesions have revealed complex evolutionary trajectories and the earliest molecular events in their development. Recent single-cell and spatial technologies further elucidate the roles of intratumoral heterogeneity and the tumor microenvironment in disease progression. This review summarizes these advances from the perspective of tissue of origin and highlights their implications for prevention, early detection, and therapeutic development.