RT Journal Article SR Electronic T1 Retrospective study of histopathological and prognostic characteristics of primary fallopian tube carcinomas: twenty-year experience (SOCRATE) JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP 1171 OP 1176 DO 10.1136/ijgc-2022-003468 VO 32 IS 9 A1 Borghese, Martina A1 Vizzielli, Giuseppe A1 Capelli, Giovanni A1 Santoro, Angela A1 Angelico, Giuseppe A1 Arciuolo, Damiano A1 Biglia, Nicoletta A1 Ferrero, Annamaria A1 Sgro, Luca Giuseppe A1 Ponzone, Riccardo A1 Scambia, Giovanni A1 Fagotti, Anna A1 Zannoni, Gian Franco YR 2022 UL http://ijgc.bmj.com/content/32/9/1171.abstract AB Objective Primary fallopian tube carcinoma represents a rare entity, accounting for about 0.75%–1.2% of all gynecological malignancies. The rationale of our study is to describe the prognosis of primary fallopian tube carcinoma.Methods We retrospectively identified patients with FIGO stage I–IV, all histology types and grading primary fallopian tube carcinoma treated in three major oncological centers between January 2000 and March 2020. Exclusion criteria were bulky tubo-ovarian carcinomas, isolated serous tubal intraepithelial carcinoma or neoadjuvant chemotherapy.Results A total of 61 patients were included. The vast majority of primary fallopian tube carcinomas were serous (96.7%) and poorly differentiated (96.7%) and arose from the fimbriated end of the tube (88.5%). Larger tumor size correlated with higher probability of correct preoperative differential diagnosis of primary fallopian tube carcinoma (p=0.003). Up to 82.4% of patients with small tumors (≤15 mm) presented with high FIGO stage (≥IIA). The most common site of metastasis was pelvic peritoneum (18.8%) and among 59% of patients who underwent lymphadenectomy smaller tumors had higher rate of nodal metastasis (42.9%≤10 mm vs 27.3%>50 mm). After 46.0 months of mean follow-up there were 27 recurrences (48.2%). The most common site of relapse was diffuse peritoneal spread (18.5%). The 5-year disease-free survival was 45.2% and 5-year overall survival was 75.5%. Of note, 42.9% of patients with stage IVB survived >36 months.Conclusion Primary fallopian tube carcinoma is a biologically distinct tumor from primary epithelial ovarian carcinoma and it is mostly located in the fimbriated end of the tube. In addition, it is characterized by a high rate of retroperitoneal dissemination even at apparently an early stage and its size does not correlate with FIGO stage at presentation.All data relevant to the study are included in the article or uploaded as supplementary information.