Validity of the 2014 FIGO Stage IIIA1 Subclassification for Ovarian, Fallopian Tube, and Peritoneal Cancers

BACKGROUND/AIMThe 2014 International Federation of Gynecology and Obstetrics (FIGO) classification subdivides patients with stage IIIA1 ovarian, fallopian tube, and peritoneal cancers by the greatest dimension of metastatic lymph node without supporting evidence. This study aimed to assess the validity of this subdivision. PATIENTS AND METHODSA retrospective single-institution cohort study was performed in patients with ovarian, fallopian tube, or peritoneal cancer from 2009 to 2020. We compared outcomes between patients diagnosed with IIIA1(i) (metastasis ≤10 mm in the greatest dimension) and IIIA1(ii) (metastasis >10 mm in the greatest dimension). RESULTSOf the 895 patients, 46 (5.1%) were classified as stage IIIA1, 20 as IIIA1(i), and 26 as IIIA1(ii). In stage IIIA1(ii), there were significantly more cases of serous carcinoma (p