Overview
Endometrial Cancer
1. Overview
Endometrial Cancer is malignancy arising from the lining of the womb (uterus). It is the most common gynaecological cancer in developed countries.
"The Cancer of Unopposed Estrogen".
Epidemiology
- Age: Usually post-menopausal (peak 60-70).
- Trend: Rising incidence due to obesity epidemic.
- Good News: Usually presents early (Stage 1) due to bleeding, so prognosis is generally good.
2. Pathophysiology
Two main types:
- Type 1 (Endometrioid): 80%. Estrogen-dependent. Associated with obesity/PCOS. Grade 1-2. Good prognosis.
- Type 2 (Serous/Clear Cell): 20%. Estrogen-independent. Aggressive. Poor prognosis. Resembles Ovarian cancer.
The "Unopposed Estrogen" Theory
Estrogen causes endometrial proliferation. Progesterone causes maturation/shedding. If you have High Estrogen + Low Progesterone -> Hyperplasia -> Atypia -> Cancer.
Risk Factors (mnemonic: ENDOMET)
- Elderly.
- Nulliparity (No pregnancy break from cycles).
- Diabetes / Obesity (Adipose tissue converts androgens to estrone).
- Menstrual irregularity (PCOS / Anovulation).
- Estrogen monotherapy (HRT without progesterone).
- Tamoxifen (Estrogen blocker in breast, but stimulator in uterus).
- Lynch Syndrome (HNPCC).
3. Clinical Features
- Post-Menopausal Bleeding (PMB): Bleeding >12 months after LMP.
- Rule: PMB is Cancer until proven otherwise. (Even though only 10% of PMB is cancer).
- Watery Discharge (Pink/brown).
4. Diagnosis
Gold Standard: Histology (Biopsy).
1. Transvaginal Ultrasound (TVUSS)
- Measures Endometrial Thickness (ET).
- Post-menopausal Threshold:
- <4mm: Probability of cancer <1%. Reassure.
- >4mm: Needs Biopsy.
2. Biopsy Methods
- Pipelle Biopsy: Outpatient. Thin tube sucks cells. Sensitivity 80-90%.
- Hysteroscopy + D&C: Gold Standard. Camera into womb. Visualizes lesion and takes directed biopsy.
3. Staging (FIGO)
- MRI Pelvis + CT Chest/Abdo.
- Stage 1: Confined to Uterus (1a <50% myometrium, 1b >50%).
- Stage 2: Cervical stroma invasion.
- Stage 3: Adnexa/Vagina/Nodes.
- Stage 4: Bladder/Rectum/Distant.
5. Management Algorithm
┌─────────────────────────────────────────────────────────────────────────────┐
│ ENDOMETRIAL CANCER MANAGEMENT │
├─────────────────────────────────────────────────────────────────────────────┤
│ │
│ DIAGNOSIS CONFIRMED (Endometrioid Adenocarcinoma) │
│ ↓ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ 1. SURGERY (The Mainstay) │ │
│ │ • Procedure: TLH + BSO │ │
│ │ (Total Laparoscopic Hysterectomy + Bilateral Salpingo- │ │
│ │ Oophorectomy). │ │
│ │ • Why Ovaries? They produce estrogen (feeding tumor) and are a │ │
│ │ site of metastasis. │ │
│ │ • Peritoneal Washings taken. │ │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ ↓ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ 2. ADJUVANT THERAPY (Based on Risk) │ │
│ │ • **Low Risk** (Stage 1a, Grade 1): Surgery alone. │ │
│ │ • **Intermediate Risk**: Vaginal Vault Brachytherapy. │ │
│ │ - "Internal radiotherapy" to top of vagina (common recurrence). │ │
│ │ • **High Risk** (Stage 1b G3 or Stage 3): │ │
│ │ - External Beam Radiotherapy (EBRT) + Chemotherapy (Carbo/Taxol).│ │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ ↓ │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ 3. PALLIATIVE / UNFIT FOR SURGERY │ │
│ │ • High Dose Progestogens (Mirena Coil + Oral Provera). │ │
│ │ • Reverses the estrogen effect. Can be used for fertility sparing │ │
│ │ in very young women (rare/complex). │ │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ │
└─────────────────────────────────────────────────────────────────────────────┘
6. Complications
- Surgical: Ureteric injury, Bleeding, VTE (High risk due to age/cancer/obesity).
- Lynch Syndrome: Patients need screening for Colorectal Cancer.
7. Prognosis
- Stage 1: >90% 5-year survival.
- Generally excellent compared to Ovarian/Cervix cancer because symptoms (bleeding) appear EARLY.
8. Special Considerations
Tamoxifen
- Used for Breast Cancer.
- Increases risk of Endometrial Ca by 2-3x.
- Any bleeding on Tamoxifen needs urgent hysteroscopy.
Obesity
- The driving force. Adipose tissue contains Aromatase, which converts Androstenedione -> Estrone (an estrogen).
- Weight loss is key for prevention.
9. Key Clinical Pearls
Exam-Focused Points
- PMB Clinic Rule: PMB -> TVUSS -> Hysteroscopy (if ET >4mm).
- Protective Factors: COCP (Progesterone protection), Smoking (Anti-estrogenic effect - controversial but true), Muliparity.
- Lynch Syndrome: HNPCC = Colon + Endometrial + Ovarian cancer.
- Pipelle: Can be done in GP/Clinic without anesthetic. If it fails (cervix stenosed), need Hysteroscopy.
- Atrophic Vaginitis: The most COMMON cause of PMB (thin dry skin bleeds). But Cancer is the most IMPORTANT cause.
Common Exam Scenarios
- 65yo obese woman, diabetic, PMB. Dx? (Endometrial Ca).
- 55yo on Tamoxifen for breast cancer has spotting. Management? (Urgent referral Hysteroscopy).
- TVUSS shows ET 12mm in post-menopausal woman. Next step? (Biopsy).
10. Patient Explanation
What causes it?
"It is often linked to an imbalance of hormones. Fat cells produce estrogen, which thickens the womb lining. If this lining gets too thick over many years, the cells can turn cancerous."
What is the treatment?
"The standard treatment is to remove the womb and ovaries (Hysterectomy). We can usually do this through 'keyhole' surgery (laparoscopy). Because you bled early, we likely caught it early, which means surgery alone might cure it."
11. Evidence & Guidelines
Key Guidelines
| Guideline | Organization | Year | Key Points |
|---|---|---|---|
| PMB Management | RCOG (GTG 67) | 2016 | 4mm cutoff for TVUSS. |
| Endometrial Cancer | ESGO / ESTRO | 2021 | Risk stratification for adjuvant tx. |
Evidence-Based Recommendations
| Recommendation | Evidence Level |
|---|---|
| Laparoscopic Hysterectomy | High (LACE Trial: Safe & less morbidity than open) |
| Progestogens for unfit | Moderate |
| Lymphadenectomy | Moderate (Selective use) |
13. References
- Galaal K, et al. Laparoscopy versus laparotomy for the management of early stage endometrial cancer. Cochrane Database Syst Rev. 2012.
- Colombo N, et al. ESMO-ESGO-ESTRO Consensus Conference on Endometrial Cancer. Int J Gynecol Cancer. 2016.