RESUMEN
INTRODUCTION: Pelvic high-grade serous carcinomas (HGSCs) include carcinoma of ovary, fallopian tube, and peritoneum. Five-year survival, irrespective of the stage, is between 35-40%. Most patients are diagnosed in advanced stages of the disease. The new revised and expanded dualistic model of ovarian carcinogenesis shows that type II tumors are composed for the most part of high-grade serous ovarian carcinoma, carcinosarcoma, undifferentiated carcinoma and can be further subdivided into morphologic and molecular subtypes. Many type II carcinomas develop from STIC predominantly in the distal portion of the fallopian tube and it is very likely the point of the origin of a significant subset of the pelvic high-grade serous carcinomas. OBJECTIVE: To provide an overview of major changes in our understanding of the origin of ovarian cancer, that led to the revision of FIGO (International Federation of Gynecology and Obstetrics) classification and its unification for the ovary, fallopian tube and peritoneum. We summarize the new classification, main changes compared to the former one and their clinical impact. METHODS: For this review, we have used the results of studies and review articles on the subject published in English up to October 2016. They were identified through a search of literature using PubMed, MEDLINE-Ovid, Scopus and Cochrane Library with the keywords ("serous tubal intraepithelial carcinoma" or "high-grade serous ovarian carcinoma" or "FIGO ovarian cancer staging 2014"). We retrieved and assessed potentially relevant studies, and checked the reference lists of all papers of interest to identify additional relevant publications. CONCLUSION: The origin of most cases of pelvic HGSC (carcinoma of ovary, the fallopian tube, and peritoneum) is expected in the fallopian tube epithelium. The main changes in the revised FIGO classification for extrauterine pelvic serous carcinomas were subdivision of stages IC, III and IV and elimination of the stage IIC, based on new knowledge and prognostic data. A prerequisite for the proper treatment of patients is to perform adequate surgical and pathological staging, including determining the grade of carcinoma. These factors, coupled with appropriately performed operation with zero postoperative residuum (R0), are the most important prognostic factors for patients with carcinoma of the ovary, fallopian tube, and peritoneum.