Ovarian Cancer

Overview & referral

See also Ovarian cysts, masses & accidents. Very few symptoms in early disease — it is usually discovered late or incidentally on imaging for another reason. Ovarian cancer is the eighth most commonest cancer in Australian women.

Demographics: ~10 in 10,000 women/year; 5% of all female cancers; 20% of all gynae cancers. More common after 45yrs, peak incidence 60–65.

Risk factors: family history (ovarian, breast or bowel cancer), nulliparity or infertility, first child after age 35, BRCA1/BRCA2, Ashkenazi Jewish descent, early menarche (<12yrs) and late menopause, oestrogen-only HRT or fertility treatment. The COCP is protective, as is having children.

History features: fatigue, increased abdominal girth (ascites), early satiety, lower abdominal pain/ache, GI symptoms (diarrhoea, constipation, epigastric discomfort), urinary frequency/urgency, abnormal vaginal bleeding, dyspareunia, weight loss.

Investigations: pelvic ultrasound + Ca125, ± AFP/bHCG/LDH if a germ-cell tumour is suspected (younger patients).

Management: refer to gynaecology/gynae-oncology for laparoscopy/laparotomy (diagnosis, staging, debulking) + adjuvant chemotherapy.

Types, symptom frequency, CA-125 caveats & treatment detail

Three types of ovarian cancer:

• Epithelial (90% of cases) — arises from cells on the outside of the ovary (most common)
• Germ cell (~4% of cases) — arises from egg-producing cells; can be cured with chemotherapy (PEB: cisplatin, etoposide, bleomycin)
• Stromal — arises from supporting ovarian tissue (rare)

Symptoms are often vague, generalised and non-gynaecological — consider ovarian cancer if such symptoms persist beyond one month. Reported frequency by category: abdominal 77%, gastrointestinal 70%, constitutional (e.g. fatigue) 50%, urinary 34%, pelvic 26%.

Assessment: history should cover age, parity, menopausal status, family history (ovarian/breast/bowel cancer on both sides), and recent test results. Examination: abdominal palpation (firm resistance, unexpected fullness, shifting dullness) and vaginal/rectal exam (hard irregular mass in the Pouch of Douglas, adnexal masses).

Investigation pathway for vague, persistent (>1 month) abdominal symptoms:

1. Careful history + physical examination (abdominal palpation, pelvic assessment).
2. If a mass is identified clinically → transvaginal ultrasound + Ca125 (preferred — more sensitive than transabdominal for detecting an abdominal mass), or abdominal ultrasound + Ca125, or CT + Ca125.
3. If no mass is identified clinically but symptoms persist, the same imaging + Ca125 combination is still used to investigate.
4. Mass confirmed + Ca125 elevated → refer to a specialist gynaecological oncology unit.
5. Mass confirmed + Ca125 low → refer appropriately to the specialist unit best suited to the likely cause (gynaecological, surgical, urological or gastroenterological — e.g. peritoneal tumour, omental cake).

Ca125 caveats: should never be used alone to rule ovarian cancer in or out. A very high value supports the diagnosis, but a low value is not reassuring because the test is non-specific. Conditions that can also elevate Ca125 include:

• Gynaecological: acute PID, uterine fibroids, adenomyosis, benign ovarian neoplasm, endometriosis, functional ovarian cyst, Meigs’ syndrome, ovarian hyperstimulation, menstruation
• Non-gynaecological: active hepatitis, acute pancreatitis, chronic liver disease/cirrhosis, congestive heart failure, diverticulitis, non-malignant ascites, pericarditis, pneumonia, polyarteritis nodosa, SLE, renal disease
• Other malignancies: any disseminated intra-abdominal cancer, GI cancer, breast cancer (especially metastatic), mesothelioma

Management detail:

• Surgery — laparotomy for removal, diagnosis and staging/identification of metastasis.
• Chemotherapy — commonly cisplatin/carboplatin + paclitaxel/docetaxel after surgery; with widespread disease, chemotherapy may be given first and surgical response assessed afterwards.
• Radiation therapy — to the pelvis or other sites of spread, alone or after chemotherapy.
• Targeted therapy — bevacizumab and olaparib (see PARP-inhibitor update below for how this has expanded).
• Palliative care as needed.
• No ovarian cancer screening programme exists in Australia. No proven prevention — prophylactic oophorectomy in women with a strong family history does not always prevent cancer (primary peritoneal cancer can still occur).