📋 Key Information Summary
- Ovarian cancer is the 8th most common cancer in Australian women and the most lethal gynaecological malignancy — ~1,800 new diagnoses and ~1,000 deaths per year in Australia.
- ~75% of women present at FIGO Stage III–IV with peritoneal dissemination; 5-year overall survival remains ~46% (all stages).
- High-grade serous carcinoma (HGSC) accounts for ~70% of epithelial ovarian cancers and is the subtype most responsive to platinum-based chemotherapy.
- Key modifiable risk factors include nulliparity, obesity, endometriosis, and talcum powder use; protective factors include OCP use, multiparity, and breastfeeding.
- Germline BRCA1/BRCA2 pathogenic variants account for ~15% of cases; all women with non-mucinous ovarian cancer should be referred for genetic counselling and testing.
- CA-125 is the principal tumour marker for HGSC; HE4 and ROMA score may aid pre-surgical risk assessment in adnexal masses.
- Primary treatment is maximal cytoreductive surgery (ideally no macroscopic residual disease) followed by adjuvant platinum-taxane chemotherapy (carboplatin AUC5 + paclitaxel 175 mg/m² q3w × 6 cycles).
- Neoadjuvant chemotherapy (NACT) followed by interval debulking surgery is an alternative for patients with unresectable disease or poor surgical candidates.
- PARP inhibitors (olaparib, niraparib) are PBS-listed for maintenance in newly diagnosed advanced HGSC with BRCA1/2 mutation or HRD-positive tumours, and in platinum-sensitive relapse.
- Hyperthermic intraperitoneal chemotherapy (HIPEC) at interval debulking may improve outcomes in selected patients but remains under evaluation in Australia.
- Aboriginal and Torres Strait Islander women have higher mortality rates and later-stage diagnosis due to barriers in access to specialist care and genetic testing.
- Bevacizumab is PBS-listed in combination with chemotherapy for advanced-stage disease; angiogenesis inhibition improves PFS especially in high-risk subgroups.
Introduction & Australian Epidemiology
Ovarian cancer is the most lethal gynaecological malignancy in Australia and worldwide. It encompasses a heterogeneous group of neoplasms arising from the ovary, fallopian tube, or primary peritoneal surface. Due to the absence of effective screening and non-specific early symptoms, the majority of women present with advanced-stage disease when cure is less achievable.
In Australia, approximately 1,800 women are diagnosed with ovarian cancer each year, and around 1,000 die from the disease, making it the 8th most common cancer in women but the 6th leading cause of cancer death. The age-standardised incidence rate is approximately 10.4 per 100,000 women per year (AIHW, 2023).
The 5-year relative survival for all stages combined is approximately 46%, a figure that has improved only modestly over recent decades. Survival is strongly stage-dependent: Stage I disease carries a 5-year survival exceeding 90%, whereas Stage IV disease falls below 20%.
This guideline covers the major epithelial ovarian cancers (serous, endometrioid, clear cell, mucinous) with emphasis on high-grade serous carcinoma (HGSC). Germ cell tumours and sex cord-stromal tumours, which have distinct biology and management, are addressed briefly.
Epidemiology & Risk Factors
Incidence in Australia
Ovarian cancer is predominantly a disease of post-menopausal women, with a median age at diagnosis of 64 years. Incidence increases with age and peaks in the 75–79 age group. The lifetime risk is approximately 1 in 85.
| Statistic | Value (Australia) |
|---|---|
| New cases/year | ~1,800 |
| Deaths/year | ~1,000 |
| Age-standardised incidence | 10.4 per 100,000 |
| 5-year relative survival (all stages) | ~46% |
| Median age at diagnosis | 64 years |
| Lifetime risk | 1 in 85 |
Risk Factors
| Category | Risk Factor | Effect |
|---|---|---|
| Increased risk | Germline BRCA1 pathogenic variant | 40–60% lifetime risk |
| Germline BRCA2 pathogenic variant | 10–27% lifetime risk | |
| Lynch syndrome (MLH1, MSH2, MSH6, PMS2, EPCAM) | 8–10% lifetime risk | |
| Endometriosis | OR 1.3–1.9 (clear cell, endometrioid) | |
| Nulliparity, early menarche, late menopause | Unopposed oestrogen hypothesis | |
| Decreased risk | Oral contraceptive pill (≥5 years) | Risk reduction ~50% |
| Multiparity, breastfeeding | Ovulation suppression | |
| Bilateral salpingo-oophorectomy | Near-complete risk elimination |
Risk-Reducing Surgery
Bilateral salpingo-oophorectomy (RRSO) is recommended for BRCA1 carriers aged 35–40 (after completion of childbearing) and BRCA2 carriers aged 40–45. Opportunistic salpingectomy at the time of benign pelvic or abdominal surgery is an emerging population-level prevention strategy (Australia's DOVE trial — Detecting OVarian cancer Early).
Pathology & FIGO Staging
Histological Subtypes
Epithelial ovarian cancers are classified by the WHO system. The dualistic model divides them into Type I (low-grade, indolent, often arising from precursor lesions) and Type II (high-grade, aggressive, often originating from serous tubal intraepithelial carcinoma of the fallopian tube).
| Subtype | Frequency | Key Features |
|---|---|---|
| High-grade serous (HGSC) | ~70% | TP53 mutations, BRCA-associated, platinum-sensitive; most common subtype |
| Endometrioid | ~10% | Associated with endometriosis; ARID1A, PIK3CA mutations; favourable prognosis |
| Clear cell | ~10% | Associated with endometriosis; ARID1A, PIK3CA mutations; relatively platinum-resistant |
| Mucinous | ~3% | KRAS mutations; often large, unilateral; poor response to standard chemo |
| Low-grade serous | ~3% | BRAF/KRAS mutations; endocrine therapy responsive; MEK inhibitor trials |
| Malignant Brenner, carcinosarcoma | <2% | Rare subtypes with variable prognosis |
FIGO Staging (2014 revision)
| Stage | Description | 5-Year Survival |
|---|---|---|
| I | Limited to ovaries/tubes | ~90% |
| IA | One ovary, capsule intact, no surface tumour | ~94% |
| IB | Both ovaries, capsules intact | ~92% |
| IC | Surgical spill, capsule rupture, positive washings | ~85% |
| II | Pelvic extension | ~70% |
| III | Peritoneal spread beyond pelvis and/or positive retroperitoneal nodes | ~35–40% |
| IV | Distant metastases (pleural effusion with +ve cytology, liver parenchymal, splenic) | ~17% |
Clinical Features & CA-125
Symptoms
Ovarian cancer frequently presents with vague, non-specific symptoms that are often attributed to benign conditions. The following symptoms, if persistent (≥12 days per month for <12 months), should prompt investigation:
- Abdominal bloating or increased abdominal girth
- Early satiety or difficulty eating
- Pelvic or abdominal pain
- Urinary frequency or urgency
- Unexplained weight loss
- Fatigue
- Change in bowel habit
Tumour Markers
| Marker | Subtype Association | Clinical Utility |
|---|---|---|
| CA-125 | HGSC (elevated in ~80%) | Diagnosis, monitoring response, surveillance; limited sensitivity in early-stage disease (~50%) |
| HE4 | Serous, endometrioid | ROMA score (combines CA-125 + HE4 + menopausal status) improves pre-surgical risk stratification |
| AFP | Yolk sac tumour | Essential in germ cell tumours; MBS item 66654 |
| β-hCG | Choriocarcinoma, mixed germ cell | Monitor during and after treatment |
| Inhibin | Granulosa cell tumour | Surveillance marker for sex cord-stromal tumours |
Diagnostic Imaging
- Transvaginal ultrasound (TVUS): First-line imaging. IOTA Simple Rules or ADNEX model used to assess malignancy risk of adnexal masses.
- Pelvic MRI: Useful for characterising indeterminate adnexal masses and assessing local extent. MBS item 63537.
- CT chest/abdomen/pelvis: Standard for staging; assessing operability and peritoneal disease burden.
- PET-CT: Not routinely recommended for primary diagnosis; may have a role in detecting recurrent disease.
Management: Surgery, Chemotherapy & PARP Inhibitors
Principles of Surgery
The cornerstone of curative-intent treatment for advanced ovarian cancer is maximal cytoreductive (debulking) surgery. The goal is complete macroscopic cytoreduction (CC-0 / R0 resection), which is the single strongest prognostic factor.
Surgical Procedures
- Total hysterectomy + bilateral salpingo-oophorectomy (TH-BSO)
- Omentectomy (infracolic or greater)
- Peritoneal stripping (diaphragm, pelvic peritoneum)
- Pelvic and para-aortic lymphadenectomy (if clinically negative)
- Bowel resection (if required for complete cytoreduction)
- Splenectomy ± distal pancreatectomy (for splenic hilum disease)
- Appendicectomy (especially if mucinous histology)
Primary vs Interval Debulking
For patients with potentially resectable disease (assessed by CT/clinical scoring), primary debulking surgery (PDS) followed by adjuvant chemotherapy is preferred. For patients with unresectable disease (e.g., extensive upper abdominal disease, poor performance status), neoadjuvant chemotherapy (NACT) × 3 cycles → interval debulking surgery (IDS) → adjuvant chemotherapy × 3 cycles is an equivalent alternative.
First-Line Chemotherapy
The standard first-line regimen is carboplatin plus paclitaxel (the ICON3/GOG-158 backbone). Intravenous (IV) administration is standard; intraperitoneal (IP) chemotherapy may be considered in selected patients with optimally debulked disease.
Dose-Dense Paclitaxel (Alternative Regimen)
Based on the JGOG 3016 trial, dose-dense paclitaxel (80 mg/m² weekly) with carboplatin AUC 6 q3w may be considered, particularly in patients with high-risk disease. The benefit is debated in non-Japanese populations; discuss in multidisciplinary team (MDT).
PARP Inhibitors — Maintenance Therapy
PARP inhibitors exploit homologous recombination deficiency (HRD) in tumour cells through synthetic lethality. They are now a standard component of first-line maintenance for advanced HGSC in Australia.
Platinum-Sensitive Relapse
Relapse >6 months after completion of first-line platinum-based chemotherapy is classified as platinum-sensitive. Re-challenge with platinum-based combination chemotherapy is standard:
- Carboplatin + Gemcitabine: Carboplatin AUC4 D1 + Gemcitabine 1000 mg/m² D1, D8 q3w × 6 cycles (AGO-OVAR 2.5 / GCIG trial)
- Carboplatin + Pegylated liposomal doxorubicin (PLD): Carboplatin AUC5 D1 + PLD 30 mg/m² D1 q4w × 6 cycles (CALYPSO trial)
- Carboplatin + Paclitaxel: Standard combination; consider if no significant residual neuropathy
Maintenance olaparib (if BRCA1/2 mutated) or bevacizumab may be added after platinum-based re-induction.
Platinum-Resistant Relapse
Relapse within 6 months of last platinum therapy carries a poor prognosis. Treatment is with single-agent non-platinum chemotherapy:
- Pegylated liposomal doxorubicin (PLD) 40–50 mg/m² IV q4w
- Weekly paclitaxel 80 mg/m² IV
- Topotecan 4 mg/m² IV D1, D8, D15 q4w
- Gemcitabine 1000 mg/m² D1, D8, D15 q4w
Consider bevacizumab in combination with single-agent chemotherapy (AURELIA trial). Participation in clinical trials is strongly encouraged.
Emerging Therapies
- Antibody-drug conjugates: Mirvetuximab soravtansine (ELAHERE®) for FRα-positive platinum-resistant disease (FDA approved; TGA evaluation pending)
- Immunotherapy: Limited activity as monotherapy; combination strategies with PARPi under investigation
- HIPEC: Hyperthermic intraperitoneal chemotherapy at IDS may improve OS in selected patients (OVHIPEC-1 trial); not yet standard of care in Australia
Monitoring & Surveillance
There is no evidence that routine intensive surveillance with CT imaging improves survival in asymptomatic patients. However, the following approach is standard in Australia:
Special Populations
Aboriginal and Torres Strait Islander Health Considerations
Investigations & Australian Lab Availability
📚 References
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- 2. Australian Institute of Health and Welfare (AIHW). Cancer data in Australia. Cat. no. CAN 122. Canberra: AIHW; 2023.
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- 8. Burger RA, Brady MF, Bookman MA, et al. Incorporation of bevacizumab in the primary treatment of ovarian cancer. N Engl J Med. 2011;365(26):2473–2483 (GOG-218).
- 9. Pujade-Lauraine E, Hilpert F, Weber B, et al. Bevacizumab combined with chemotherapy for platinum-resistant recurrent ovarian cancer: the AURELIA open-label randomized phase III trial. J Clin Oncol. 2014;32(13):1302–1308.
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- 11. van Driel WJ, Koole SN, Sikorska K, et al. Hyperthermic intraperitoneal chemotherapy in ovarian cancer. N Engl J Med. 2018;378(3):230–240 (OVHIPEC-1).
- 12. RANZCOG. College Statement: Management of women identified at increased risk of ovarian cancer. C-Obs 43. Melbourne: RANZCOG; 2023.
- 13. Cancer Australia. National Framework for Gynaecological Cancer Control. Surry Hills: Cancer Australia; 2022.
- 14. National Health and Medical Research Council (NHMRC). Clinical Practice Guidelines for the Management of Ovarian Cancer in Australia. Canberra: NHMRC; 2004 (under review).
- 15. Australian Commission on Safety and Quality in Health Care (ACSQHC). Australian Cancer Care Pathways: Ovarian Cancer. Sydney: ACSQHC; 2023.