Current Clinical Staging of Uterine Adenocarcinoma
The current staging system for uterine adenocarcinoma is the 2009 FIGO surgical/pathologic staging system, which remains the standard in clinical practice as of 2023, though a 2023 FIGO update incorporating molecular classification has been published but requires broader validation before widespread adoption. 1
The 2009 FIGO Staging System (Current Standard)
The 2009 FIGO system is a surgical/pathologic staging system that replaced the outdated 1970 clinical staging system, which was inaccurate in 15-20% of patients. 1 This system emphasizes thorough surgical assessment including histologic grade, myometrial invasion depth, and extent of extrauterine spread. 1
Stage I: Disease Confined to Uterus
Stage II: Cervical Involvement
- Stage II: Tumor invades cervical stroma 1
- Critical change: Patients with endocervical glandular (mucosal) involvement WITHOUT cervical stromal invasion are no longer considered Stage II—they remain Stage I 1
Stage III: Local/Regional Spread
- Stage IIIA: Tumor invades serosa and/or adnexa 1
- Stage IIIB: Vaginal and/or parametrial involvement 1
- Stage IIIC1: Pelvic lymph node involvement alone 1
- Stage IIIC2: Para-aortic lymph node involvement (with or without pelvic nodes), reflecting inferior survival 1
Stage IV: Distant Spread
- Stage IVA: Tumor invades bladder and/or bowel mucosa 1
- Stage IVB: Distant metastases including intra-abdominal and/or inguinal lymph nodes 1
Key Staging Principles
Positive Peritoneal Cytology
Positive peritoneal cytology no longer upstages disease in the 2009 FIGO system, as its importance as an independent risk factor has been questioned. 1 However, FIGO and AJCC continue to recommend obtaining and recording peritoneal washings, as positive cytology may add to the effect of other risk factors. 1
Surgical Staging Requirements
Staging must be performed by a multidisciplinary team with expertise in imaging, pathologic evaluation, and surgery. 1 The extent of surgical staging depends on preoperative and intraoperative assessment by experienced surgeons. 1
Pathologic nodal assessment for apparent uterine-confined endometrial cancer informs both stage and adjuvant therapy. 1 However, if final pathology shows noninvasive endometrioid histology, nodal assessment can be eliminated. 1
The NCCN sentinel lymph node (SLN) algorithm is recommended if sentinel node mapping is used. 1
Pathologic Assessment
Expert pathologic review determines the specific histotype: endometrioid, serous, clear cell, carcinosarcoma, or undifferentiated/dedifferentiated. 1 Assessment should include evaluation of the uterus, fallopian tubes, ovaries, and peritoneal cytology. 1
The 2023 FIGO Update: Not Yet Standard Practice
A 2023 FIGO staging revision has been published that incorporates molecular classification (POLEmut, MMRd, NSMP, p53abn) and creates additional substages based on histologic type, LVSI, and molecular features. 2 However, this system represents a significant departure from traditional anatomical staging and requires multi-institutional validation before widespread adoption. 3
The 2023 system has been criticized for being introduced "too much, too soon" without adequate global appraisal and input from all relevant societies. 3 Until broader validation occurs, the 2009 FIGO system remains the standard for clinical practice. 1
Common Pitfalls to Avoid
- Do not upstage patients based solely on positive peritoneal cytology—this is no longer part of the staging criteria 1
- Do not classify endocervical glandular involvement without stromal invasion as Stage II—these patients remain Stage I 1
- Ensure proper distinction between Stage IIIC1 (pelvic nodes only) and IIIC2 (para-aortic involvement), as survival differs significantly 1
- Recognize that clinical staging is inaccurate in 15-20% of cases—surgical/pathologic staging is essential for accurate prognostication 1