Many women worry about getting ovarian cancer, sometimes because one of their relatives has developed the illness. This section explains:

• Why having just one, or even two, relatives with cancer does not normally mean that there is an inherited genetic link in your family.
• What we know about the causes of ovarian cancer.
• What you can do to help yourself.

The cause of most ovarian cancers is not known. But we do know that some things – called risk factors – can increase our chances of developing cancer. Some risk factors are very likely to cause cancer, whereas others will only very slightly increase our likelihood of getting it.

Having a particular risk factor for cancer, or being exposed to one, doesn’t mean that we will definitely get cancer; just as not having it doesn’t mean that we won’t. Smoking is a good example of this. If you smoke, it isn’t certain that you will get lung cancer; just as if you don’t smoke, it’s not certain that you won’t. But smoking will greatly increase your risk of getting lung cancer. Nine out of ten people who develop lung cancer are smokers.

Cancer is very common and nearly one in three of us will develop it at some time during our lives. This means that most of us will have relatives who have had cancer. Surveys have shown that many people are worried that a history of cancer in their family greatly increases their risk. People often worry that an increased risk of cancer can be inherited, or passed on from one generation to another. In fact less than 1 in 10 cases of cancer (between 5 and 10%) have been shown to be due to a family history of the disease.

Genes carry the biological information we inherit from our parents. They affect the way our bodies grow, work and look. Changes (mutations) in certain genes can increase the risk of ovarian cancer in family members who inherit the genetic change. But only a small number of ovarian cancers are thought to be due to an inherited altered gene running in the family.

Two gene changes – called BRCA1 and BRCA2 mutations – can run in a family and increase the ovarian and breast cancer risk of family members who inherit the genetic change. But they are not common.

How does my family history affect my risk of developing ovarian cancer?

It is only likely that a genetic mutation that can increase your ovarian and breast cancer risk is present in your family if, on one side of the family (either your mother’s or your father’s family), you have:

• at least two close relatives (mother, sisters or daughters) with ovarian cancer
• one close relative who had ovarian cancer and another who had breast cancer under 50 (or both cancers in the same person)
• one close relative who had ovarian cancer and two relatives who had breast cancer under 60
• three close relatives with bowel or womb (uterine) cancer and one with ovarian cancer.

If your family is like this, and you are worried about developing ovarian cancer yourself, you might want to talk to your GP. Your GP will ask you questions about your family history. It seems that gene changes are more common among people from Jewish backgrounds. So if you have Jewish ancestry (where a faulty cancer gene is more common) and close relatives with breast or ovarian cancer, you might want to tell your GP. If your GP thinks there’s a chance that you might have an increased risk of developing ovarian cancer because of your family history, they will refer you to a genetic counsellor, family cancer clinic or a cancer specialist.

If you only have one middle-aged or elderly relative who has developed ovarian cancer, or a case of breast or ovarian cancer on each side of your family, this does not significantly increase your risk. If you had one of the ovarian or breast cancer genes in your family, then it is likely that more than one relative on the same side of the family would have developed ovarian or breast cancer.

If you are still worried

It can be a normal reaction to severe illness in the family or to bereavement to feel more vulnerable to the same disease. If you have spoken to your GP and you are not at an increased risk of getting ovarian cancer, but you can’t stop worrying, you may find it helpful to see a counsellor, who can help you get things back into perspective. You can ask your GP, or call our nurses for details of a local service. You could also call the Cancer Counselling Trust to speak to a counsellor.

Mind, the mental health charity, has published a leaflet called 'How to Stop Worrying'.

Other risk factors in the development of ovarian cancer usually play a bigger role than family history.

Age

The main risk factor for ovarian cancer is age. Although ovarian cancer is rare, the older you are the more likely it is that you might develop it. Nine out of ten (90%) of ovarian cancer cases are in women over 45, and half of ovarian cancers happen in women over 65.

Child bearing

Women who have never had children are more likely to get ovarian cancer than women who have given birth, although the risk is still low.

Hormone levels

Women who had their first period early (under 12) and their menopause late (after 50) are slightly more likely to get ovarian cancer.

Fertility treatments

Research has shown that the use of fertility treatments may increase the risk of developing ovarian cancer. But it has also been suggested that it is being infertile that increases ovarian cancer risk, rather than any treatment you may have for it. There is more research going on to try to clarify this.

Hormone Replacement Therapy (HRT)

Data from a number of large studies have shown a small but significant increase in risk of developing ovarian cancer among women who take both oestrogen-only and combined oestrogen and progesterone HRT. The risk of ovarian cancer increases the longer it is taken, but gradually returns to normal once HRT is stopped.

It has been suggested that talcum powder, certain diets, and some supplements, can increase a woman’s risk of developing ovarian cancer. However, there is no good evidence to support these claims. Scientists are studying many different possible factors, but so far the risk factors listed in this leaflet are the only ones where there is good evidence.

There is good evidence that the contraceptive pill decreases women’s risk of getting ovarian cancer. But the pill is associated with a slight increase of breast cancer risk. Having children, particularly before the age of 30, and breastfeeding them, decreases the risk of ovarian cancer. Apart from the above, there is not much evidence that women can do a lot to decrease their ovarian cancer risk. But here are some suggestions that might help to reduce your overall risk of getting cancer and other serious diseases.

Stop smoking

Smoking is responsible for about 1 in 3 of all cancers (30%) and for 9 in 10 (90%) lung cancers alone. If you smoke, giving up is the healthiest decision you can make. If you want help, ask your GP or call the NHS Smoking Helpline on 0800 169 0 169 or visit www.gosmokefree.co.uk.

Take up some regular exercise

You don’t need to go to the gym – walking, cycling or gardening, done regularly, can be enough.

Try to maintain a healthy weight

It can help to eat a balanced diet, which contains plenty of fruit and vegetables. Your GP can give you more advice.

Limit the amount of alcohol you drink

The European Code Against Cancer recommends that to reduce their risk of developing cancer women should drink no more than one unit of alcohol per day. A unit is half a pint of ordinary strength beer, lager or cider; or one small glass (125ml) of wine; or a single measure (25ml) of spirits.

Although making these changes may reduce your risk of developing cancer, they do not guarantee that you won’t get cancer. But all of the above strategies will improve your health generally.

Ovarian cancer can often be difficult to treat because it is usually diagnosed relatively late. Ovarian cancer that is found earlier is easier to treat successfully. Unfortunately, the early signs and symptoms of ovarian cancer are unclear and can also be caused by many, often harmless, problems that have nothing to do with cancer. You should see your GP if you have one or more of the following symptoms for more than 12 days a month:

• feeling full persistently
• difficulty eating
• abdominal (tummy) pain
• pelvic pain
• bloating
• frequent need to pass water
• increased abdominal size.

You should also see your GP if you have sudden symptoms, such as:

• abnormal vaginal bleeding
• changes in bowel habit (constipation or diarrhoea)
• excessive tiredness (fatigue)
• indigestion or nausea.

It is important to remember that in the vast majority of women these symptoms occur for reasons other than cancer. But it is worth seeing your doctor, if these symptoms continue and you are worried. You are not wasting your doctor’s time.

You can get more information about the symptoms of ovarian cancer, and a symptom diary from Ovarian Cancer Action.

We don't know if screening women, without any symptoms, for ovarian cancer would save lives, or if it would only lead to unnecessary worry and tests without actually helping much. A large study, called the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS), is looking at this. The trial stopped recruiting women in 2005 but it will be some time before we know the results.

Women with a strong family history of ovarian cancer can join a screening study that investigates whether regular check-ups for women who have a higher risk of developing ovarian cancer are helpful. This study is called the UK Familial Ovarian Cancer Screening Study.