Stage Anatomic Involvement
Stage I Tumor confined to the uterine corpus
IA No Myometrial Invasion
IB <50% Myometrial Invasion
IC ≥50% Myometrial Invasion
Stage II Cervical Involvement
IIA Endocervical Glandular Involvement
IIB Cervical Stromal Invasion
Stage III  
IIIA Positive peritoneal cytology, and/or Tumor invasion into uterine serosa, and/or Adnexal involvement
IIIB Vaginal Involvement
IIIC Metastases to pelvic and/or pelvic lymph nodes
Stage IV  
IVA Bladder and/or Bowel Involvement
IVB Distant metastases, including abdominal disease, and/or Inguinal lymph node involvement
Table 1: 1998 FIGO Staging System for Endometrial Cancer.