Endometrial cancer — structured SAQ (15 marks)

(a) Diagnostic pathway and TVUS threshold (3 marks)

One mark per point, maximum three. ^[2][6]

• Immediate pathway: any postmenopausal bleeding is endometrial cancer until proven otherwise — arrange transvaginal ultrasound and endometrial biopsy (pipelle); there is no role for watch-and-wait.
• TVUS threshold: endometrial thickness of 4 to 5 mm or more in a postmenopausal woman not on HRT mandates biopsy (sensitivity over 95 per cent, negative predictive value over 95 per cent for cancer below this threshold).
• Confirm the bleeding is uterine and exclude other sources (atrophic vaginitis, cervical cancer, vaginal cancer) on speculum examination.^[2][6]

(b) Surgical management and lymph node strategy (4 marks)

One mark per point. ^[2][4]

• Cornerstone: total hysterectomy with bilateral salpingo-oophorectomy; laparoscopic or robotic preferred for apparent stage I disease (shorter stay, less blood loss, equivalent oncological outcomes).
• Lymph node strategy: sentinel lymph node biopsy with fluorescent indocyanine green and cervical injection.
• Trial evidence: the FIRES trial (Rossi et al 2017) showed sentinel node biopsy detected nodal metastases with high sensitivity and negative predictive value, with far less morbidity than full lymphadenectomy. ^[4]
• Peritoneal washings on opening; systematic lymphadenectomy reserved for high-risk disease (grade 3, deep invasion, serous/clear cell, suspected nodes).^[2]

(c) FIGO 2023 stage, risk group and adjuvant therapy (5 marks)

One mark per point. ^[1][3]

• FIGO 2023 stage with molecular modifier: anatomic stage is IA2 (under 50 per cent myometrial invasion, no LVSI), but the p53abn molecular class up-stages the tumour — recorded as IAmp53abn (or the equivalent up-staged designation under FIGO 2023, with the "m" subscript indicating molecular class).
• Risk group: molecular class elevates the risk stratification — p53abn tumours behave aggressively and are managed as high-risk despite the anatomic stage.^[3]
• Recommended adjuvant therapy: chemoradiotherapy is favoured for p53abn high-risk disease — pelvic external beam radiotherapy plus chemotherapy (the PORTEC-3 regimen: two cycles of cisplatin concurrent with EBRT, then four cycles of carboplatin and paclitaxel).^[2]
• Evidence: the PORTEC-3 molecular analysis (Leon-Castillo 2020) showed 5-year recurrence-free survival with chemoradiotherapy versus radiotherapy alone was 59 per cent versus 36 per cent for p53abn tumours (P = 0.019), regardless of histologic type — the subgroup that benefits most from chemoradiotherapy.^[3]
• Contrast with POLEmut: POLEmut stage IA-IB is down-staged (IAmPOLEmut) and may avoid adjuvant therapy — the opposite polarity.^[1]

(d) Fertility-sparing management if 34 years old (3 marks)

One mark per point. ^[5]

• Selection criteria: grade 1 endometrioid cancer confined to the endometrium on MRI (stage IA, no myometrial invasion), no lymphovascular space invasion, MMR-proficient status, strongly wishing fertility.
• Management: high-dose oral progestin (medroxyprogesterone 400 to 600 mg daily, or megestrol 160 to 320 mg daily) or the levonorgestrel intrauterine system, with endometrial sampling every 3 months to assess response. Response rates 60 to 75 per cent; recurrence 25 to 40 per cent after regression.^[5]
• Multidisciplinary decision with clear counselling: definitive hysterectomy is recommended once childbearing is complete because of the recurrence risk; referral to reproductive medicine.