What is ovarian cancer?
Ovarian cancer is when abnormal cells in the ovary begin to grow and divide in an uncontrolled way. The cells can grow into surrounding tissues or organs and may spread to other areas of the body.
There are different types of ovarian cancer. The type of ovarian cancer you have depends on the type of cell it starts in.
The ovaries
The ovaries are part of a woman's reproductive system, which is made up of the:
- vulva
- vagina
- womb or uterus (which includes the cervix)
- fallopian tubes
- ovaries
There are 2 ovaries, one on each side of the body. The ovaries produce an egg each month in women of childbearing age.
This video shows more detail about the female reproductive system. It is 1 minute and 50 seconds long.
The female reproductive system includes a number of parts. The ovaries hold the eggs which are released each month during child bearing age. They also produce sex hormones which control periods. The fallopian tubes connect the ovaries to the womb (also called the uterus).
When an egg is released it travels down the fallopian tube towards the womb. At this time, sperm from the male can pass into the fallopian tube where it may meet the egg and fertilise it. Fertilised eggs pass down the fallopian tube to the womb, which holds and protects the baby during pregnancy. The lining of the womb is called the endometrium. It thickens during the menstrual cycle ready for pregnancy. If you don’t become pregnant you have a period which is when the lining sheds.
The cervix is the lower part of the womb. It is the opening into the vagina. During a period or menstruation blood passes from the womb through the cervix and then to the vagina. The vagina also opens and expands during sexual intercourse and stretches during childbirth to allow a baby to come out.
On the outside of the body is the vulva. It is made up of two pairs of lips. Between these is the opening of the vagina. Above the vagina is the urethra: a short tube that carries urine from the bladder to outside of the body and above the urethra is the clitoris: a very sensitive area that gives sexual pleasure.
For more information about cancers that can start in the female reproductive system, go to cruk.org/cancer-types
The ovaries and fertility
Women are able to have children between puberty (when the periods start) and the 
(or change of life, when the periods stop). The age when periods start and stop varies a great deal.
In the middle of each (mid way between periods), one of the ovaries releases an egg. It travels down the fallopian tube to the womb. The lining of the womb gets thicker and thicker, ready to receive a fertilised egg. If the egg is not fertilised by sperm, the thickened lining of the womb is shed as a period. Then the whole cycle begins again.
Ovarian hormones
The ovaries also produce the female sex hormones. These are:
- oestrogen
- progesterone
The ovaries produce these hormones throughout the years when women can become pregnant. The hormones control the menstrual cycle. As you get older and closer to menopause, the ovaries make less and less of these hormones and periods eventually stop.
Ovarian hormones also help to protect the heart and bones. And maintain brain and immune system health.
The ovaries produce a small amount of the male hormone testosterone. It is not completely clear what role testosterone has in women. But doctors think it helps with muscle and bone strength. And it may have a role in a woman’s sex drive (libido).
Where does ovarian cancer start?
The ovaries are made up of different types of cells. The type of ovarian cancer you have depends on the type of cell it starts in.
The main types of ovarian cancer are:
- epithelial ovarian cancers which start in the surface layer which covers the ovary, fallopian tube or
peritoneum - germ cell ovarian cancer which begins in the cells that develop into eggs
- sex cord stromal cancers which begin in the tissues that support the ovaries and produce hormones
Knowing which type of ovarian cancer you have helps your doctors decide what treatment you need.
How common is ovarian cancer?
Around 7,500 women are diagnosed with ovarian cancer in the UK each year. This makes ovarian cancer the 6th most common cancer in women.
Who gets it?
Ovarian cancer can affect women, some transgender men and non-binary people assigned female at birth.
Your risk of developing ovarian cancer increases as you get older. The risk is greatest in those aged between 75 and 79.
We don't know exactly what causes ovarian cancer. But some factors may increase or reduce the risk.
