PT - JOURNAL ARTICLE AU - MORIKAZU MIYAMOTO AU - HITOSHI TSUDA AU - ATSUSHI SUGIURA AU - TSUNEKAZU KITA AU - YOSHITAKA KATAOKA AU - KENJI ISHII AU - KAZUYA KUDO AU - HIROKO MATSUURA AU - HIROKI ISHIBASHI AU - HIDEKI IWAHASHI AU - TAIRA HADA AU - RIE SUZUKI AU - MASASHI TAKANO TI - Grade 1 Endometrioid Carcinoma With an Area of Serous Carcinoma Less than 5% Is More Aggressive than Stage IA Pure-type Grade 1 Endometrioid Carcinoma AID - 10.21873/invivo.12370 DP - 2021 Mar 01 TA - In Vivo PG - 1205--1209 VI - 35 IP - 2 4099 - http://iv.iiarjournals.org/content/35/2/1205.short 4100 - http://iv.iiarjournals.org/content/35/2/1205.full SO - In Vivo2021 Mar 01; 35 AB - Background/Aim: In 2020, the percentages were removed from the World Health Organization’s criteria for mixed carcinoma. The aim was to examine the clinical significance of an area of serous carcinoma (SC) <5%. Patients and Methods: Our study included 236 patients with the 2009 International Federation of Obstetrics and Gynecology (FIGO) stage IA grade 1 endometrioid carcinoma (EG1) from multiple hospitals. EG1 patients with an area of SC <5% and those with pure-type EG1 were retrospectively compared. Results: In the multivariate analysis for recurrence, an area of SC <5% was an independent risk factor [hazard ratio (HR)=101.51, p<0.01]. In the multivariate analysis for progression-free survival, an area of SC <5% was identified as a negative prognostic factor (HR=62.43, p<0.01). Conclusion: EG1 with an area of SC <5% may be more aggressive than pure-type EG1 at FIGO stage IA.