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.
The ovaries are part of the female reproductive system, which also includes the fallopian tubes, uterus (womb), cervix (the neck of the uterus), vagina (birth canal) and vulva (external genitals).
The ovaries are two small, walnut-shaped organs. They are found in the lower part of the abdomen (belly). There is one ovary on each side of the uterus, close to the end of the fallopian tubes.
Each ovary is made up of:
- epithelial cells – found on the outside of the ovary in a layer known as the epithelium
- germ (germinal) cells – found inside the ovaries, which eventually mature into eggs (ova)
- stromal cells – form connective (supporting) tissue within the ovaries, and make the hormones oestrogen and progesterone.
Near the ovaries are many organs and other structures, including the:
- bladder – stores urine or wee
- small bowel – involved in digestion
- rectum – stores faeces or poo
- peritoneum – the lining of the abdomen
- omentum – the sheet of fatty tissue that hangs in front of the large bowel like an apron.
Each month, from puberty to menopause, the ovaries release an egg (ovum). This is known as ovulation.
The egg travels from the fallopian tube to the uterus. If the egg is fertilised by a sperm, it attaches to the lining of the uterus and grows into a baby. If the egg is not fertilised, the lining of the uterus is shed and flows out of the body through the vagina. This flow is known as a period or menstruation.
The hormones oestrogen and progesterone control ovulation and menstruation. As you get older, the ovaries gradually make less of these hormones.
When the levels of oestrogen and progesterone fall low enough, periods finally stop. This is known as menopause. After menopause, you can’t have a child naturally.
Your guide to best cancer care
A lot can happen in a hurry when you’re diagnosed with cancer. The guide to best cancer care for ovarian cancer can help you make sense of what should happen. It will help you with what questions to ask your health professionals to make sure you receive the best care at every step.
Read the guide
Types of ovarian cancer
There are many types of ovarian cancer. The three main types start in different cells – epithelial, stromal or germ cells.
- 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 cordstromal 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.
- 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 ovarian cancer?
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.
Learn more about ovarian cancer statistics and trends
The symptoms of ovarian cancer can be similar to other common conditions. This can make it difficult to diagnose early. Symptoms are more likely to develop as the cancer grows and may include:
- pressure, pain or discomfort in the abdomen or pelvis
- a swollen or bloated abdomen
- changes in appetite (e.g. not feeling like eating, feeling full quickly)
- changes in toilet habits (e.g. constipation, diarrhoea, passing urine more often, increased wind)
- indigestion and feeling sick (nausea)
- feeling very tired
- unexplained weight loss or weight gain
- changes to periods such as heavy or irregular bleeding, or vaginal bleeding after menopause
- pain when having sex.
If you have any of these symptoms and they are new for you, are severe or continue for more than a few weeks, it is best to have a check-up.
Keep a note of how often the symptoms occur and make an appointment to see your general practitioner (GP). Ovarian Cancer Australia has produced a diary for recording symptoms. You can also use it to help talk about your health concerns with your doctor.
The causes of ovarian cancer are largely unknown, but factors that can increase the risk of developing ovarian cancer include:
- age – ovarian cancer is most common in women over 50 and in women who have stopped having periods, and the risk increases with age.
- genetic factors – up to 20% of serous ovarian cancers (the most common subtype) are linked to an inherited faulty gene, and a smaller proportion of other types are also related to genetic faults.
- family history – having one or more close blood relatives diagnosed with ovarian, breast, bowel or uterine cancers, or having Ashkenazi Jewish ancestry.
- endometriosis – this condition is caused by tissue from the lining of the uterus growing outside the uterus.
- reproductive history – women who have not had children, who have had assisted reproduction, or who have had children after the age of 35 may be slightly more at risk.
- lifestyle factors – some types of ovarian cancer have been linked to smoking or being overweight.
- hormonal factors – such as early puberty or late menopause. Some studies suggest that menopause hormone therapy (MHT), previously called hormone replacement therapy (HRT), may increase the risk of ovarian cancer, but the evidence is not clear.
Some factors reduce the risk of developing ovarian cancer. These include having children before the age of 35, breastfeeding, using the combined oral contraceptive pill for several years, and having your fallopian tubes tied (tubal ligation) or removed.
Does ovarian cancer run in families?
Ovarian cancer most often occurs for unknown reasons, but some cases are due to an inherited faulty gene. Having an inherited faulty gene does not mean you will definitely develop ovarian cancer, and you can inherit a faulty gene without having a history of cancer in your family.
About 15% of women with ovarian cancer have an inherited fault in the BRCA1 or BRCA2 genes or other similar genes. The BRCA gene faults can also increase the risk of developing breast cancer.
Less commonly, a group of gene faults known as Lynch syndrome is associated with ovarian cancer and can also increase the risk of developing cancer of the bowel or uterus. As other genetic conditions are discovered, they may be included in genetic tests for cancer risk.
More on family history and cancer
Your general practitioner (GP) will arrange the first tests to assess your symptoms. If these tests do not rule out cancer, you will usually be referred to a specialist called a gynaecological oncologist. The specialist will arrange further tests.
If ovarian cancer is diagnosed, the specialist will consider treatment options. Often these will be discussed with other health professionals at what is known as a multidisciplinary team (MDT) meeting.
During and after treatment, you will see a range of health professionals who specialise in different aspects of your care, including a gynaecological pathologist, radiologist, genetic counsellor and social worker, among others.
Asking your doctor questions will help you make an informed choice. You may want to include some of these questions in your own list.
- What type of ovarian cancer do I have?
- Has the cancer spread? If so, where has it spread? How fast is it growing?
- Are the latest tests and treatments for this cancer available in this hospital?
- What sort of genetic testing can I have? Can I see a genetic counsellor?
- Will a multidisciplinary team be involved in my care?
- Are there clinical guidelines for this type of cancer?
- What treatment do you recommend? What is the aim of the treatment?
- Are there other treatment choices for me? If not, why not?
- If I don’t have the treatment, what should I expect?
- How long do I have to make a decision?
- I’m thinking of getting a second opinion. Can you recommend anyone?
- How long will treatment take? Will I have to stay in hospital?
- Are there any out-of-pocket expenses not covered by Medicare or my private health cover? Can the cost be reduced if I can’t afford it?
- How will we know if the treatment is working?
- Are there any clinical trials or research studies I could join?
- What are the risks and possible side effects of each treatment?
- Will I have a lot of pain? What will be done about this?
- Can I work, drive and do my normal activities while having treatment?
- Will the treatment affect my sex life and fertility? What are my fertility options?
- Should I change my diet or physical activity during or after treatment?
- Are there any complementary therapies that might help me?
- How often will I need check-ups after treatment? Who should I see?
- If the cancer returns, how will I know? What treatments could I have?
Understanding Ovarian Cancer
Download our Understanding Ovarian Cancer booklet to learn moreDownload now
Expert content reviewers:
Dr Nisha Jagasia, Gynaecological Oncologist, Mater Hospital Brisbane, QLD; Sue Hayes, Consumer; Bronwyn Jennings, Gynaecology Oncology Clinical Nurse Consultant, Mater Health, QLD; Dr Andrew Lee, Radiation Oncologist, Canberra Region Cancer Centre and Canberra Hospital, ACT; A/Prof Tarek Meniawy, Medical Oncologist, Sir Charles Gairdner Hospital, WA; Caitriona Nienaber, Cancer Council WA; Jane Power, Consumer; A/Prof Sam Saidi, Senior Staff Specialist, Gynaecological Oncology, Chris O’Brien Lifehouse, NSW.
Page last updated:
The information on this webpage was adapted from Understanding Ovarian Cancer - A guide for people with cancer, their families and friends (2022 edition). This webpage was last updated in April 2022.