The ovaries are two small, oval-shaped organs, each about 3 cm long and 1 cm thick in size. They are found in the lower part of the abdomen (the pelvic cavity). There is one ovary on each side of the uterus.
Each ovary has an outer covering made up of a layer of cells called the epithelium. Inside are germ cells, which will eventually mature into eggs (ova). The ovaries also release the female hormones oestrogen and progesterone from cells called sex-cord stromal cells.
An egg, called an ovum, is released from one of the ovaries each month (ovulation). The egg travels down the fallopian tube to the uterus. If the egg is fertilised by sperm, it can grow into a baby. If an egg is not fertilised by sperm, it disintegrates and – with the lining of the uterus – passes out of the vagina in the monthly period (menstruation).
As a woman gets older, the ovaries gradually produce less oestrogen and progesterone. The production of mature eggs also decreases and the woman’s periods become irregular and eventually stop. This is known as menopause, which usually happens between the ages of 45 and 55. After menopause, it is no longer possible to have a child by natural means.
Ovarian cancer is a malignant tumour in one or both ovaries. Some cases of ovarian cancer can form in the fallopian tube and spread to the ovary.
There are many types of ovarian cancer. The three most common types are:
Some women (usually younger women) are diagnosed with a borderline tumour. This is not considered to be cancer because, although it can spread, it does not invade other organs. For this reason borderline tumours are called low malignant potential tumours and usually have a good prognosis.
Each year, about 1400 Australian women are diagnosed with ovarian cancer. The average age at diagnosis is 64. It is the tenth most common cancer in women in Australia. Ovarian cancer is usually diagnosed in women over 50.
Ovarian cancer may not cause any symptoms in its early stages, or it may cause only vague ones that are hard to recognise. If symptoms occur, they may include a swollen, bloated abdomen; pressure, discomfort or pain in the abdomen or pelvis; heartburn and nausea; changes in toilet habits (e.g. constipation, diarrhoea, frequent urination due to pressure, increased flatulence); tiredness and loss of appetite; unexplained weight loss or weight gain; changes in your menstrual pattern or postmenopausal bleeding; or pain during sex.
If these symptoms are new for you or continue over a four-week period, make an appointment with your general practitioner (GP). Having these symptoms does not necessarily mean you have cancer, but it is best to have a check-up.
Ovarian Cancer Australia has produced a symptom diary and a smartphone app, called KISS & Makeup, to help women record any symptoms and talk about their health concerns with their doctor.
The causes of ovarian cancer are unknown, however risk factors include:
About one in ten women diagnosed with ovarian cancer is believed to have inherited a fault in a gene that increased her risk of developing ovarian cancer. Not all women who inherit a faulty gene will develop ovarian cancer, but it increases a woman’s chance of developing ovarian cancer over the risk of the average woman.
Two main genetic conditions known to increase the risk of ovarian cancer include hereditary breast/ovarian cancer (fault in the BRCA1 and BRCA2 gene) and less commonly, hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome, as it was formerly known).
If you have one or more of the risk factors listed below, you may like to talk with someone at a familial cancer clinic. Usually, these centres do not require a doctor’s referral and can be found in most major public hospitals. You can also find a list of familial cancer clinics on the Ovarian Cancer Australia website.
Some things may protect against ovarian cancer. These are called protective factors, and may include having children, breastfeeding, using the combined oral contraceptive pill for several years, having your fallopian tubes tied (tubal ligation), and the surgical removal of some female reproductive organs, such as the uterus or fallopian tubes.
Any family member
A personal history
Two or more family members on the same side of the family (mother's or father's side)