Each year in Australia, there are about 1,800 new diagnoses of ovarian cancer and over 1,000 deaths, making ovarian cancer the fifth most common cause of death from cancer in women. The lifetime risk is about 1.6%, increasing to 5% if a first-degree relative is affected, and 45% and 25% respectively if the BRCA1 or BRCA2 mutation is present.

The median age of diagnosis is 63 years, with two-thirds of patients diagnosed at 55 years or older.

Histologically, tumour cells may arise from the outer epithelial lining cells of the ovary (60%), the germ cells (30%), or sex cord stromal cells (8%). Epithelial tumours of the high-grade serous type are now thought to spread to the ovarian surface after arising from secretory cells at the fimbria of the fallopian tubes, acquiring a TP53 mutation there before metastasising to the ovary as clinically evident ovarian cancer.

Serous carcinomas represent the vast majority of primary malignant ovarian tumours (75%–80%) and are composed of columnar cells with cilia. These tumours are subdivided into high-grade and low-grade serous carcinomas, which has particular relevance for BRCA-associated ovarian tumours.

As with many internal diseases, clinical presentation may be late, with vague pelvic discomfort giving way to pain and bloating, followed by more systemic symptoms as the disease advances.

The tumour marker CA 125 may only be elevated 50% of the time in early disease, rising to 80% in advanced cancer; however, false positives may occur with benign ovarian disease, leiomyomas, and endometriosis. As with tumour markers used in the follow-up of other cancers, its utility in screening and early diagnosis is limited.

The disease is advanced in 75% of cases at the time of diagnosis. Five-year survival is about 41% when local spread is detected, reducing to 30% or less with distant metastases, compared to 89% survival or above with early detection when the disease is localised.

Given the importance of this condition, I was curious to consult Professor Thomas Jobling once more on current practices of surveillance, approaches to detection and management, and how to manage risk in first-degree relatives. How should we approach an ovarian cyst found incidentally during abdominal imaging? What symptoms should we, as clinicians, be mindful of in triggering our suspicion to investigate further?

I know you will find this conversation with Professor Thomas Jobling interesting. Tom is a gynaecological oncologist, ex-AFL footballer, and medical researcher with a highly respected reputation in Melbourne and internationally. He has extensive experience with minimally invasive surgery, including robotic surgery, for gynaecologic cancer. His main research area is ovarian cancer, for which he received an Order of Australia Medal in 2017, and he is currently Head of Gynaecological Health and VMO at Peter MacCallum Hospital.

Please welcome Professor Jobling to the podcast.

References:

• Professor Tom Jobling: reception_tjobling@bigpond.com.au

• Ovarian Cancer: Cancer Australia

• Pathobiology of Ovarian Carcinomas, Chinese Journal of Cancer, 2016 Jan; 34

• Ovarian Cancer Research Alliance: https://ocrahope.org/