Vaginal cancer and VaIN — structured oral station (12 minutes)

Opening prompt — "Tell me what this is and what you do next."

Model response — say it in this order: ^[1][2]

• "This is a 3 cm ulcerated plaque on the upper posterior vaginal wall with a normal cervix and a recent normal screen — this is primary vaginal squamous cell carcinoma until a punch biopsy proves otherwise, not atrophic vaginitis."^[2]
• "I would apply the FIGO primary-vaginal definition first: a tumour involving the cervix or vulva, or a cervical or vulvar cancer within five years, is classified as that cancer. Her cervix is normal and her screen was recent, so this is a primary vaginal cancer."^[1]
• "I would punch biopsy the lesion, examine the cervix and vulva for the HPV field effect, and stage with pelvic MRI for local extent and CT or PET-CT for distant disease."^[2][3]

Examiner is listening for: biopsy before treatment, the FIGO definition applied, and MRI for staging. ^[2]

Probe 1 — "Stage her tumour."

• "FIGO staging: Stage I limited to the vaginal wall; Stage II invading paravaginal tissues but not the pelvic sidewall; Stage III pelvic wall and/or lower third vagina and/or hydronephrosis, with or without inguinal nodes; Stage IV beyond the true pelvis and/or bladder or rectal mucosa and/or distant metastases." ^[1]
• "The framework was retained through the 2018 FIGO revision — it is the staging in current use."^[1][2]

Probe 2 — "How will you treat her?"

• "Radiotherapy is the primary modality — external beam plus brachytherapy with a combined dose above 70 Gy, plus concurrent cisplatin 40 mg per square metre weekly."^[2][3]
• "The reason radiotherapy dominates is anatomical: the vagina lies against the bladder, urethra and rectum, so surgery rarely achieves clear margins for a tumour this size. Brachytherapy is essential — omitting it costs survival on SEER and NCDB data."^[3]
• "Surgery is reserved for small tumours, 2 cm or less, stage I, proximal vagina, no prior radiotherapy — this 3 cm tumour is not in that group."^[3]

Probe 3 — "What is the role of HPV here?"

• "Around four in five vaginal squamous cell carcinomas are HPV-associated, mainly HPV 16 and 18, through a VaIN-to-cancer sequence that mirrors the cervix."^[2]
• "The virus acts on a field, so I would examine the cervix and vulva for a second lesion, and counsel on smoking cessation. HPV positivity is favourable for squamous cell carcinoma."^[2][4]

Probe 4 — "She asks whether she will be cured."

This is a scored domain, not a courtesy. Demonstrate it out loud: ^[5]

• Move to her eye level, use her name: "Vaginal cancer is treated mainly with radiotherapy, and the outlook depends on the stage. The overall five-year survival is about 58 per cent, with earlier stages doing much better — stage I is about 76 per cent. I will refer you to the gynaecological oncology and radiation oncology team today."
• "Treatment can cause vaginal narrowing, so I will arrange dilator therapy and sexual health counselling, and I will keep you fully informed throughout."^[3]

Probe 5 — "What about VaIN found on her surveillance?"

• "VaIN 1 (low-grade) is observed with cytology and HPV testing, because most regress. VaIN 2 to 3 (high-grade) is treated, with surgical excision as the mainstay, mandatory when invasion cannot be excluded."^[4]
• "CO2 laser and topical imiquimod are alternatives; VaIN after hysterectomy for CIN 3 is managed surgically because the buried epithelium is unreachable by topical or laser."^[4]