The current surgery for local tumor control is based on a model of isotropic cancer spread executed as wide tumor excision. However, this perception, as a general principle, is not consistent with clinical facts. Likewise, current principles and practices for regional tumor control in gynecologic carcinomas, including sentinel node biopsies and adjuvant radiotherapy, bear an inherent risk of both under- and overtreatment. The paradigm of ontogenetic cancer fields provides a new approach to locoregional carcinoma spread, which is consistent with known clinical facts. Its execution as cancer field surgery and defense-line-directed lymph node dissection achieves markedly improved treatment results. This introduction provides an overview of the cancer field paradigm and its clinical application for gynecologic malignancies as presented in this textbook and surgical atlas.