Table 1. New 2023 FIGO staging system of carcinoma of the endometrium (adapted from Berek et al) ¹ .

FIGO Stage	Carcinoma endometrium descriptors
Stage I	Lesion confined to the body of uterus and the ovary
IA	Disease limited only to the endometrium/a nonaggressive histological type (low-grade endometroid carcinoma), with invasion of <50% myometrium with no or focal LVSI/a good prognosis disease IA1: Nonaggressive histological type limited to an endometrial polyp/confined to endometrium only IA2: Nonaggressive histological types involving <50% myometrium with no or focal LVSI IA3: Low-grade endometrioid carcinomas limited to uterus and ovary (good prognosis disease)
IB	Nonaggressive histological types with invasion of ≥ 50% of the myometrium, and with either no or only focal LVSI
IC	Aggressive histological types limited to a polyp or lesion confined to the endometrium
Stage II	Nonaggressive histological types with invasion of cervical stroma without extrauterine extension/with substantial LVSI OR an aggressive histological type with myometrial invasion
IIA	Nonaggressive histological types with invasion of the cervical stroma
IIB	Nonaggressive histological types with substantial LVSI
IIC	Aggressive histological types with any degree of myometrial involvement
Stage III	Tumor of any histological subtype with local and/or regional spread
IIIA	Invasion of uterine serosa or adnexa or both; either by direct extension or metastasis IIIA1: Spread to ovary/fallopian tube (except when meeting criteria of stage IA3) IIIA2: Involvement of uterine subserosa/spread through uterine serosa
IIIB	Metastasis or direct spread to vagina and/or to parametria or the pelvic peritoneum IIIB1: Metastasis or direct spread to vagina and/or parametria IIIB2: Metastasis to pelvic peritoneum
IIIC	Metastasis to pelvic/para-aortic lymph nodes or to both IIIC1: Metastasis to pelvic lymph nodes IIIC1i: Micrometastasis IIIC1ii: Macrometastasis IIIC2 Metastasis to the para-aortic lymph nodes up to level of renal vessels, with or without metastasis to pelvic lymph nodes IIIC2i: Micrometastasis IIIC2ii: Macrometastasis
Stage IV	Spread to bladder mucosa and/or to intestinal mucosa and/or evidence of distance metastasis
IVA	Invasion of bladder mucosa and/or intestinal/bowel mucosa
IVB	Abdominal peritoneal metastasis beyond pelvis
IVC	Distant metastasis, which includes metastasis to any extra- or intra-abdominal lymph nodes above the renal vessels, lungs, liver, brain, or bone

Abbreviations: FIGO, International Federation of Gynecology and Obstetrics; LVSI, lymphovascular space involvement.