The cancer field model claims a hierarchy of permissive tissues for local tumor progression determined by the differentiation trajectory of the cell type from which the cancer originated. Basic features observable in metazoan development are highlighted to outline topographically distinct cell type habitats and associated morphogenetic fields for successive states of ontogenesis. These form the basis for mapping ontogenetic anatomy and, consequently, cancer fields for tumor spread. As an example, the stepwise developmental pathways of the uterine cervix and the vulva from the phylotypic stage to maturity are considered, and the corresponding cancer fields are deduced, providing the foundation for ontogenetic staging and cancer field surgery of cervix and vulvar carcinoma.