Ovarian cancer
Ovarian cancer is the fourth most common women’s cancer, with around 6,800 new cases per year. The UK has one of the highest incidences of ovarian cancer in Europe.
About the ovaries
Ovaries form part of the female reproductive system. Between puberty and the menopause the ovaries release an egg regularly, usually about every 28 days. Eggs travel down the fallopian tubes to the uterus. If a pregnancy doesn’t occur, they are shed with the lining of the womb each month as the menstrual period.
The ovaries also produce oestrogen and progesterone, the female sex hormones which control the menstrual cycle (periods).
During the months before the menopause the ovaries gradually stop working. Eggs are no longer produced and oestrogen levels fall. The symptoms which some women have at this time are due to the fall in oestrogen levels.
What causes ovarian cancer?
The cause of ovarian cancer is not yet known, but there are some factors that may increase your risk and some factors which may reduce your risks of ovarian cancer. These factors include:
Many of these risk or protection factors seem to be associated with how the ovaries function. Ovarian cancer is not infectious, so you cannot catch it from anyone else and there is no evidence to suggest that sexual activity and ovarian cancer are linked. However, ovarian cancer is more common in developed countries (except Japan). It is believed that this maybe due to a high-fat diet in the western world and in particular, animal fat.
Family history of cancer
Women with two or more very close relatives who have had ovarian cancer are more at risk of getting the disease themselves. By very close relative, we mean mother, sister or daughter. Only about 5% to 10% of all ovarian cancers are thought to be hereditary.
BRCA1 and BRCA2 are two genes known to be associated with an increased risk of both breast and ovarian cancer. Families in which a fault on one of these genes is present are likely to have several individuals on the same side of the family affected with breast and/or ovarian cancer. In addition, families who have several closely related individuals affected with bowel cancer at a young age may carry a faulty gene which is associated with an increased risk of bowel cancer and ovarian cancer.
All of these genetic faults are rare but can be passed down through either parent.
If you are concerned about your family history of cancer, you can seek advice from your local genetics service (such as the one run by The Royal Marsden) through your GP or your hospital consultant.
Contraceptive pill
Taking the combined contraceptive pill (containing both oestrogen and progesterone) appears to reduce your risk of ovarian cancer. It is thought the longer you take the pill, the more your risk of ovarian cancer is decreased. By taking the combined contraceptive pill, you are not producing any eggs.
Children
Having children may decrease your risk of ovarian cancer, and not having children may increase your risk of ovarian cancer. This is because many of the risk or protection factors appear to be related to how the ovaries work. When your ovary produces an egg, the surface layer of the ovary bursts and releases an egg. The cells then divide to repair the damage. The more eggs your ovaries produce, the more the cells need to divide to repair the surface of the ovary. This increases the opportunity for any one cell to go wrong. During pregnancy, eggs stop being produced each month.
Breast-feeding
It is thought that breast-feeding your child reduces the risk of ovarian cancer. This is because when you breast feed, you do not normally produce an egg from the ovary each month. Therefore, this decreases ovarian activity.
Fertility treatment
There is no concrete evidence that taking fertility treatment does increase the risk of ovarian cancer. However, any drug which stimulates the ovary, increases ovarian activity.
Talcum powder
There has been concern about the long-term use of talcum powder. Studies have suggested that the use of talcum powder in the genital area may lead to a slight increased risk of ovarian cancer. However, the current evidence is conflicting and inconclusive, and further large scale studies are needed in order to be able to reach a definite conclusion.