Gestational Trophoblastic Neoplasia

Question 1

Types GTN

Answer 1

1. Invasive Mole
   - Most common GTN
   - Arise post complete or partial molar pregnancy
   - Histology: whole chorionic villi with trophoblstic overgrowth and invasion
2. Choriocarcinoma
   - Can follow molar pregnancy or normal gestation
   - Can arise without gestation
   -Sheets of anaplastic cyto and syncitio-trophoblasts withoutchorionic villi
   - Very malignant
   Locally invasive
   Early metastases
   * Lung 80%
   * Vaginal 30%
   * Hepatic and cerebral 10%
3. Placental site trophoblastic Tumour
   o Most cases follow a normal term pregnancy
   o Rare, locally invasive tumour
   o Associated with low bhCG, low proliferation
   o Chemotherapy resistant, hysterectomy is first line
4. Invasive Mole:
   - treated with single agent Chemo
5. Epithelioid trophoblastic tumour

Question 2

Diagnosis

Answer 2

• persistent, plateau or rise in BhCG levels
• Exclude new intrauterine pregnancy

Question 3

Examination

Answer 3

• General and vitals
• Chest auscultation
• Uterine size plapation
• vaginal examination for mets

Question 4

Investigations

Answer 4

• Full set of bloods
  -CXR
• CT abdo/pelvis

Question 5

Staging and Prognosis

Answer 5

• I: Confined to uterus – 97% 5 year survival
• II: Outside uterus but within genital tract
• III: Lung metastases
• IV: Other distant metastases – 60% 5 year survival

WHO Prognostic scoring to guide management
* Based on:
- Patient age
- Type of antecedent pregnancy
- Interval from index pregnancy
- Pre-treatment bhCG
- Largest tumour size
- Site and number of metastases
- Previously failed chemotherapy
* Low risk: 0-6, high risk: >=7

Question 6

Management

Answer 6

• Gynae-oncology referral
• Multidisciplinary meeting and pathology review
• Low risk
  o Single-agent chemotherapy with methotrexate
  o Hysterectomy if fertility not desired or to control bleeding or vaginal metastases
• High-risk
  o Multi-agent chemotherapy
  o Etoposide, methotrexate, dactinomycin alternating with cyclophosphamide and vincristine

Question 7

Follow up

Answer 7

• bhCG tracking
  o Stage I-III
• Usually followed with monthly bhCG for 12 months after treatment completed
  o Stage IV
• Usually followed with monthly bhCG for 24 months after treatment completed
• Contraception essential
  o Should avoid pregnancy until given all-clear from oncology team
  o All options reasonable after liaison with oncology
  o Consider DVT risks of OCP during chemotherapy
  o IUD not advised if uterine disease
• In future pregnancies placenta should be sent for histopathology and bhCG tracked to 0 post-partum