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OG34.1 | Endometrial Cancer — SDL Guide (Part 3)

Self-Assessment

This section consolidates the highest-yield examination points from this module. A final-year student encountering endometrial cancer questions should be able to: (1) Identify the classic risk factor cluster (postmenopausal, obese, diabetic, nulliparous, late menopause) and explain each through the oestrogen excess mechanism. (2) State the TVUS endometrial thickness threshold for postmenopausal women (≤4 mm = safe without biopsy; >4 mm = biopsy required). (3) Apply FIGO 2023 staging correctly — especially IA (<50% myometrial invasion) versus IB (≥50%) versus Stage II (cervical stromal invasion). (4) Distinguish Type I (endometrioid, low grade, oestrogen-driven, better prognosis) from Type II (serous/clear cell/carcinosarcoma, high grade, oestrogen-independent, poor prognosis). (5) Describe the staging laparotomy components: TAH + BSO + pelvic lymphadenectomy + para-aortic lymphadenectomy + peritoneal washings. (6) Match the adjuvant therapy to the risk group: low risk = observation; intermediate = vaginal brachytherapy; high risk/advanced = EBRT ± chemotherapy.

The most common viva trap is confusing endometrial staging with cervical staging — they are different systems. In endometrial cancer, myometrial invasion depth drives Stage I sub-staging; there is no equivalent in cervical cancer (where tumour size drives IB sub-staging). Practise by working through staging scenarios before looking up the answer.

Side-by-side comparison diagram of endometrial FIGO 2023 and cervical FIGO 2018 staging systems, with a central column highlighting five key differences including Stage II criteria, sub-staging basis, and molecular modifiers. — **Panel A:** Endometrial FIGO 2023 cascade: Stage IA–IC (uterine confinement), Stage II (cervical stromal invasion with dagger callout), Stages IIIA–IIIC2 (regional spread), Stages IVA–IVB (distant); molecular modifier inset (POLE, MMR, NSMP, TP53). **Panel B:** Key differences column: Stage II criterion (stromal vs parametrial), sub-staging basis (depth+molecular vs size), molecular modifiers presence, shared IIIC1/IIIC2 logic, primary route of early spread. **Panel C:** Cervical FIGO 2018 cascade: Stages IA1–IB3 (size-based microinvasion and visible disease), Stages IIA–IIB (vaginal/parametrial extension), Stages IIIA–IIIC2 (pelvic wall, nodes), Stages IVA–IVB (adjacent organ and distant).

SELF-CHECK

Which combination of findings correctly characterises a Type II endometrial cancer?

A. Postmenopausal obese woman; Grade 1 endometrioid; PTEN mutation; superficial myometrial invasion

B. Non-obese older woman; uterine serous carcinoma; TP53 mutation; early peritoneal spread

C. Premenopausal woman with PCOS; endometrial hyperplasia with atypia; low grade

D. Tamoxifen user; Grade 2 endometrioid; microsatellite instability

Reveal Answer

Answer: B. Non-obese older woman; uterine serous carcinoma; TP53 mutation; early peritoneal spread

Type II endometrial cancers are not oestrogen-driven, arise from atrophic endometrium, typically in non-obese older postmenopausal women, and include serous carcinoma, clear cell carcinoma, and carcinosarcoma. Their molecular hallmark is TP53 mutation (and/or HER2 amplification). They spread early by exfoliation and peritoneal dissemination. Options A, C, and D describe Type I (oestrogen-driven, endometrioid, PTEN/MSI/KRAS mutations, associated with obesity/PCOS/tamoxifen).

CLINICAL PEARL

A staging trap that has generated marking errors in examinations and clinical mistakes in practice: endocervical gland involvement alone does NOT make the tumour Stage II. In the FIGO system, Stage II endometrial cancer requires invasion of the cervical stroma — the connective tissue supporting the cervical epithelium. Tumour cells found within endocervical glands (i.e., within the glandular lumen, floating in mucus) without stromal disruption are Stage I disease that has merely extended into the glandular space. This distinction is made by the pathologist on microscopy and has real management consequences: Stage I (endocervical gland involvement only) receives adjuvant therapy per Stage I risk criteria, while true Stage II (stromal invasion) receives pelvic EBRT.

Interactive practice: Multiple Choice

Interactive practice: True / False