What is ovarian cancer?

Ovarian cancer starts when cells in one or both ovaries, the fallopian tubes or the peritoneum become abnormal, grow out of control and form a lump called a tumour. Cancer of the fallopian tube was once thought to be rare, but recent research suggests that many ovarian cancers start in the fallopian tubes. There are different types of ovarian cancer.

If ovarian cancer spreads beyond the ovaries, it often spreads to the organs in the abdomen and pelvis. Sometimes an ovarian tumour is diagnosed as a borderline tumour (also known as a low malignant potential tumour). This tumour is not considered to be cancer but can still spread within the abdomen.

What are the different types of ovarian cancer?

There are many types of ovarian cancer. The three main types start in different cells: epithelial, stromal or germ cells.

epithelial

• the most common type of ovarian cancer (about 90% of cases)
• starts on the surface of the ovary (epithelium), fallopian tube or peritoneum
• subtypes include serous, endometrioid, clear cell, and mucinous
• serous is the most common subtype; it’s divided into high grade and low grade
• most high-grade serous ovarian cancers start in cells at the end of the fallopian tube
• mostly occurs over the age of 60

stromal cell (or sex cord stromal tumours)

• rare cancer (8% or less)
• starts in the cells in the ovaries that produce the hormones oestrogen and progesterone
• may produce extra hormones, such as oestrogen
• usually occurs between the ages of 40 and 60

germ cell

• rare type of ovarian cancer (about 4% of cases)
• starts in the egg-producing (germinal) cells
• usually occurs under the age of 40

Non-cancerous ovarian tumour

borderline tumour

• abnormal cells that form in the tissue covering the ovary
• doesn’t grow into the supportive tissue (stroma)
• grows slowly

How common is it?

Each year, about 1720 Australians are diagnosed with ovarian cancer – this includes serous carcinomas of the fallopian tube. Over 80% of people diagnosed are over the age of 50, but ovarian cancer can occur at any age. It is the 9th most common cancer in females in Australia.

Anyone with ovaries can get ovarian cancer, so it mostly affects women. Transgender men and intersex people can also get ovarian cancer if they have ovaries. For information specific to you, speak to your doctor.