Radiation Oncology/Endometrium/Staging

Current staging
Endometrial Carcinomas

FIGO Staging (2023)

PMID 37593813 -- "FIGO staging of endometrial cancer: 2023"


 * Stage I  -   Confined to the uterine corpus and ovary
 * IA - Disease limited to the endometrium OR non-aggressive histological type, i.e., low-grade endometroid, with invasion of less than half of myometrium with no or focal LVSI OR good prognosis disease
 * IA1 : Non-aggressive histological type limited to an endometrial polyp OR confined to the endometrium
 * IA2 : Non-aggressive histological types involving less than half of the myometrium with no or focal LVSI
 * IA3 : Low-grade endometrioid carcinomas limited to the uterus and ovary
 * IB - Non-aggressive histological types with invasion of half or more of the myometrium, and with no or focal LVSI
 * IC - Aggressive histological types limited to a polyp or confined to the endometrium
 * Stage II  -   Invasion of cervical stroma without extrauterine extension OR with substantial LVSI OR aggressive histological types with myometrial invasion
 * IIA - Invasion of the cervical stroma of non-aggressive histological types
 * IIB - Substantial LVSI of non-aggressive histological types
 * IIC - Aggressive histological types with any myometrial involvement
 * Stage III  -   Local and/or regional spread of the tumor of any histological subtype
 * IIIA - Invasion of uterine serosa, adnexa, or both by direct extension or metastasis
 * IIIA1 : Spread to ovary or fallopian tube (except when meeting stage IA3 criteria)
 * IIIA2 : Involvement of uterine subserosa or spread through the uterine serosa
 * IIIB - Metastasis or direct spread to the vagina and/or to the parametria or pelvic peritoneum
 * IIIB1 : Metastasis or direct spread to the vagina and/or the parametria
 * IIIB2 : Metastasis to the pelvic peritoneum
 * IIIC - Metastasis to the pelvic or para-aortic lymph nodes or both
 * IIIC1 : Metastasis to the pelvic lymph nodes   {IIIC1i: micrometastasis; IIIC1ii: macrometastasis}
 * IIIC2 : Metastasis to para-aortic lymph nodes up to the renal vessels, with or without metastasis to the pelvic lymph nodes  {IIIC2i: micrometastasis; IIIC2ii: macrometastasis}
 * Stage IV  -   Spread to the bladder mucosa and/or intestinal mucosa and/or distant metastasis
 * IVA - Invasion of the bladder mucosa and/or the intestinal/bowel mucosa
 * IVB - Abdominal peritoneal metastasis beyond the pelvis
 * IVC - Distant metastasis, including metastasis to any extra-or intra-abdominal lymph nodes above the renal vessels, lungs, liver, brain, or bone

Staging footnotes:


 * Disease limited to low-grade endometrioid carcinomas involving the endometrium and ovaries (Stage IA3) must be distinguished from extensive spread of the endometrial carcinoma to the ovary (Stage IIIA1), by the following criteria: 1) no more than superficial myometrial invasion is present (<50%); 2) absence of extensive/substantial LVSI; 3) absence of additional metastases; and 4) the ovarian tumor is unilateral, limited to the ovary, without capsule invasion/rupture (equivalent to pT1a).
 * LVSI: LVSI as defined in WHO 2021: extensive/substantial, ≥5 vessels involved.
 * Aggressive histological types:
 * non-aggressive: G1-2 EEC.
 * aggressive: G3 EEC, serous, clear cell, undifferentiated, mixed, mesonephric-like, gastrointestinal mucinous type carcinomas, and carcinosarcomas

AJCC 7th Edition (2009)
 * Corresponds to updated FIGO staging (2009)
 * FIGO 2009 PMID 19345353 -- "Revised FIGO staging for carcinoma of the endometrium."


 * This staging now applies only to endometrial carcinomas and there is now a separate staging for uterine sarcomas.
 * Carcinosarcomas (MMMT) should be staged as high grade carcinoma.

Primary Tumor: (FIGO Stage in parentheses)
 * Note: FIGO uses pathologic staging


 * Tis - in situ
 * Note: FIGO no longer includes Stage 0
 * T1 (I) - confined to corpus
 * T1a (IA) - limited to endometrium or invades less than 1/2 of myometrium
 * T1b (IB) - invades &ge; 1/2 of myometrium
 * T2 (II) - invades stromal tissue of the cervix but does not extend beyond uterus
 * Note: endocervical glandular involvement only should be considered as Stage I not Stage II
 * T3
 * T3a (IIIA) - involves serosa and/or adnexa (direct extension or metastasis)
 * T3b (IIIB) - vaginal involvement (direct extension or metastasis) or parametrial involvement
 * T4 (IVA) - invades bladder mucosa and/or bowel mucosa

Regional Lymph Nodes:
 * N0 - none
 * N1 (IIIC1) - metastasis to pelvic lymph nodes
 * N2 (IIIC2) - metastasis to para-aortic lymph nodes
 * Note: Regional nodes include obturator, internal iliac, external iliac, common iliac, para-aortic, presacral, and parametrial
 * Note: For pathologic staging, FIGO classifies cases with <6 resected LNs as pNX

Distant Metastases:
 * M0 - none
 * M1 (IVB) - distant metastasis - includes inguinal LN, intraperitoneal disease (including omentum), lung, liver, or bone.

Stage Grouping:
 * Corresponds to FIGO stage given above (in parentheses)

Changes from 6th Edition:
 * No longer includes uterine sarcoma (now staged with a new staging system)
 * Positive peritoneal cytology is no longer considered (previously was T3a/IIIA)
 * Involvement of the endocervical glands is no longer considered (previously was Stage IIA)
 * Stages IA+IB combined (now: IA). IC moved to IB.
 * Stage IIIC subdivided into IIIC1 and IIIC2.

Older staging systems
FIGO moved to surgical staging in 1988 (AJCC 6th edition same). There is also a clinical staging system developed by FIGO in 1971.

Note: until the update of the FIGO / AJCC in 2009, uterine sarcomas and carcinomas were staged using the same system

AJCC 6th Edition (2002)
 * IA - Limited to endometrium
 * IB - < 1/2 of myometrium
 * IC - 1/2 or more of myometrium
 * II - invades cervix
 * IIA - glandular epithelium of endocervix
 * IIB - stroma of cervix
 * III - extra-uterine
 * IIIA - involves serosa and/or adnexa (direct extension or mets) and/or ascites or positive peritoneal washings
 * IIIB - vaginal involvement (direct extension or mets)
 * IIIC - LN+ (pelvic and/or paraaortic)
 * IV - other organs
 * IVA - bladder or bowel
 * IVB - distant mets

Clinical staging
Staging is now surgical (see above), but clinical staging may be utilized for non-operative pts.

FIGO 1971


 * I - Confined to corpus
 * IA - Length of uterine cavity 8 cm or less
 * IB - Length of uterine cavity > 8 cm
 * II - Involves corpus and cervix, but no extension beyond the uterus
 * III - Extends outside uterus but not outside true pelvis
 * IV - Outside the true pelvis or involves bladder or rectum
 * IVA - Involves bladder, rectum, sigmoid, or small bowel
 * IVB - Distant mets