Understanding Ovarian Cancer

This information has been prepared to help you understand more about ovarian cancer. The information is an introduction to the diagnosis, treatment and effects of ovarian cancer but is by no means exhaustive. We cannot advise about the best treatment for you. You need to discuss this with your doctors. However, we hope this information will answer some of your questions and help you think about the questions you want to ask your doctors.

• The ovaries
• What is ovarian cancer?
• How common is it?
• Risk factors
• Symptoms
• Prevention and detection
• Diagnosis
• Further information

The ovaries

The ovaries are part of the female reproductive system.

• The ovaries are almond-shaped organs, each about 3cm long and 1cm thick.
  
  
• They are found inside the pelvic cavity, one on each side of the uterus and are very close to the end of the Fallopian tubes.
  
  
• 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).

In a woman of childbearing age, a mature egg is released from one of the ovaries each month (ovulation) and travels down the Fallopian tube to the uterus (womb). If the egg is not fertilised by sperm, it passes out of the uterus with the monthly period (menstruation).

The ovaries also contain cells that release the female hormones; oestrogen and progesterone. These cells are called sex-cord stromal cells.

As a woman gets older, the ovaries gradually produce less oestrogen and progesterone. At the same time, the production of eggs also decreases and the woman's periods become irregular and eventually stop. This is known as menopause and usually happens between the ages of 45 and 55. After menopause, it is no longer possible to have a child.

What is ovarian cancer?

Ovarian cancer is a malignant tumour in one or both ovaries. The four main types of ovarian cancer are named after the part of the ovary affected.

• Epithelial ovarian cancer - Starts in the epithelium: the surface of the ovary and is the m ost common type of ovarian cancer. Nine out of 10 ovarian cancers are epithelial.
  
  
• Borderline tumours - A group of epithelial tumours that don't spread as quickly as other forms of ovarian cancer.
  
  
• Germ cell and sex-cord stromal cell ovarian cancer - Very uncommon, Germ cell cancer usually only affects women under 30 years of age. Sex-cord stromal cell cancers develop in the cells that release the female hormones. This type of ovarian cancer can occur at any age.

How common is it?

Each year in Australia, around 1,300 women are diagnosed with ovarian cancer. One in 104 Australian women will develop ovarian cancer by the age of 75.

Most ovarian cancer tumours are present for some time before they are discovered – sometimes ovarian cancer is found unexpectedly during an operation, such as a hysterectomy.

As it’s difficult to detect until it is at an advanced stage, prognosis for ovarian cancer is often poor. Around 850 women die of ovarian cancer in Australia each year.

Risk factors

The cause of ovarian cancer is unknown. However, the following factors increase a woman's chance of developing ovarian cancer:

• Age: About nine out of 10 ovarian cancers occur in women aged over 45.
  
  
• Family history: Around 5-10% of cases of ovarian cancer are caused by inheriting a damaged gene. If you have a close relative who has had cancer of the breast or ovary, you may be at increased risk of ovarian cancer. However, most women who develop ovarian cancer do not have a family history of the disease.
  
  
• Not having children: Ovarian cancer is more common in women who have not had children. Women who have taken the contraceptive pill for a number of years seem to have a lower risk. The exact reason is uncertain. It could be that ovarian cancer is more likely to develop when the ovaries do not have a break from ovulation during a woman's lifetime.

However, many women who have these risk factors do not develop ovarian cancer.

There is no proven link between ovarian cancer and a high-fat diet, using talcum powder around the genital area, or the mumps virus.

Symptoms

Ovarian cancer is often a silent disease in the early stages, which means many women have no symptoms. If symptoms do appear, they are usually vague and may include:

• Swelling, discomfort and pain in the abdomen
• Gastro-intestinal symptoms such as heartburn, nausea and bloating
• Changes in bowel habits, such as constipation and diarrhoea
• Tiredness and loss of appetite
• Unexplained weight loss or weight gain
• Changes in menstrual pattern or postmenopausal bleeding

These symptoms are common to many illnesses, and most women with these symptoms will not have ovarian cancer. Only tests can confirm the diagnosis.

Prevention and detection

Prevention is better than cure, so The Cancer Council Australia and its state members work to raise awareness of women’s cancers and to educate women about how to lower their cancer risk.

You and your circle of friends can reduce your risk of developing cancer by:

• Learning what the risk factors are and where possible taking steps to decrease your risk
• Knowing the early warning signs and monitoring your health
• Leading a healthy lifestyle

Detection

At the moment there is no one reliable test to check healthy women for early signs of ovarian cancer, and many ovarian cancers are not found until they have spread and are more difficult to treat.

Much research is being done around the world on better ways to find ovarian cancer early.

Unlike Pap tests, which test for cervical cancer before symptoms appear, there is no screening program for ovarian cancer. The Pap test does not detect ovarian cancer.

There is a blood test that measures the level of a particular protein in the blood, called CA-125. The level may be higher in women with ovarian cancer, however it may also be higher in women who have common gynaecological conditions such as endometriosis or fibroids.

A CA-125 test on its own does not diagnose ovarian cancer.

Diagnosis

Most ovarian cancer tumours are present for some time before they are discovered. Sometimes ovarian cancer is found unexpectedly during an operation, such as a hysterectomy.

Your GP will arrange the first tests to check out your symptoms. This can be a worrying and tiring time, especially if you need several tests. If these tests do not rule out cancer, you will usually be referred to a gynaecological oncologist, a specialist in treating women with ovarian cancer. This specialist will arrange further tests and advise you about treatment options.

• Physical examination - The doctor will do a pelvic examination to check for a mass or lump in the lower abdomen.
  
  
• Blood tests - Some ovarian cancers produce chemicals that are released into the blood. These chemicals are the proteins that the cancer cells make. They are called tumour markers. You will have a blood test to check the level of your tumour markers. If your levels of the chemicals rise, you may have ovarian cancer. However, you could have raised markers and not have ovarian cancer, as levels may be higher in women who have common gynaecological conditions, such as endometriosis or fibroids. The type of marker depends on the type of tumour. However, some tumours will not have any of these tumour markers. The most common types of tumour markers are CA125, beta human chorionic gonadotrophin, fetoprotein and inhibin. Testing your blood for these tumour markers is one way to help diagnose cancer. Tumour marker tests are also used during treatment to check the progress of your illness. Other blood tests may be taken to help with your diagnosis and to check the effects of treatment.
  
  
• X-rays and ultrasounds - Routine chest and abdominal x-rays may be taken. An ultrasound uses soundwaves to make up a picture of the inside of the abdomen and pelvic area. This test is used to reveal any lumps. An ultrasound can be done in two ways:
  
  
  • Abdominal ultrasound: a hand-held device called a transducer is passed over your pelvic area. The echoes from the soundwaves are turned into a picture by a computer.
    
    
  • Transvaginal ultrasound: the transducer is inserted into your vagina to show up the ovaries, which sometimes cannot be seen by the abdominal ultrasound. Some women find the procedure a little embarrassing and uncomfortable, although it is not painful. Discuss the procedure with your doctor and ultrasound specialist if you have any concerns.
  
  You may also have a bowel x-ray to make sure that your symptoms are not caused by a bowel problem. This x-ray is called a barium enema. A white chalky liquid is put into your bowel through your back passage (rectum) and x-rays are then taken. The barium enema is not painful but can be uncomfortable.
  
  
• Biopsy - None of the tests above can definitely diagnose ovarian cancer. The only way this can be done is to examine a piece of tissue under the microscope. This is called a biopsy and is usually taken during an operation called a laparotomy. A biopsy also helps determine the type of ovarian cancer. This means that ovarian cancer is usually diagnosed and treated at the same time.

Further information

For further information on cervical cancer, call The Cancer Council Helpline on 13 11 20 or contact your local state or territory office of The Cancer Council (see the contact us page for details)

© 2008 Cancer Council