There are several types of epithelial ovarian cancer. They are currently all treated in a similar way.
They include:
- serous – the most common type
- mucinous
- endometrioid
- clear cell
- undifferentiated or unclassifiable.
There are also non-epithelial cancers that can affect the ovaries. This section does not cover treatment for these. We have separate information on non-epithelial ovarian cancers, such as germ cell tumors (ovarian teratomas) and sarcomas.
The causes of ovarian cancer are not yet completely understood. The risk of developing ovarian cancer is very low in young women and increases as women get older. More than 8 out of 10 (80% of) ovarian cancers occur in women over the age of 50. On this page we’ve listed some factors that are known to affect a woman’s chance of developing ovarian cancer. Some increase the risk and some decrease it.
Hormonal factors
| Hormonal factors that increase the risk of developing ovarian cancer | Hormonal factors that decrease the risk of developing ovarian cancer |
| • Starting periods at a young age | • Taking the contraceptive pill |
| • Having a later menopause | • Having children (the risk decreases with each additional pregnancy) |
| • Taking hormone replacement therapy (HRT) (the risk decreases after stopping taking it) | • Breastfeeding |
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Hormonal factors that increase the risk of developing ovarian cancer
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Hormonal factors that decrease the risk of developing ovarian cancer
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Physical factors
Height
Women who are taller than 5ft 7in are slightly more likely to get ovarian cancer than shorter women.
Endometriosis
Endometriosis is a condition where the lining of the womb grows outside the womb. Having endometriosis slightly increases the risk of developing ovarian cancer.
Ovarian cysts
Having ovarian cysts before the age of 30 increases your risk of developing ovarian cancer in future. But most women who have had ovarian cysts before the age of 30 won’t ever develop ovarian cancer.
Lifestyle factors
Smoking
Smoking cigarettes increases the risk of developing a type of ovarian cancer called mucinous cancer.
Weight
Some studies have found a link between being very overweight (obese) and an increased risk of developing ovarian cancer.
Diet
Eating a diet high in animal fats and low in fresh fruit and vegetables may increase the risk of developing ovarian cancer.
Family history
If your mother or sister has had ovarian cancer, this slightly increases your risk of developing it. But the risk is still low – about 1 in 20 (5%). We have more information available if you are worried about ovarian cancer and genetics. Women who have two or more close relatives who’ve had ovarian cancer or certain other types of cancer may be at a higher risk.
Inherited risk
A small number of ovarian cancers, about 1 in 10 (10%), are thought to be due to an inherited altered gene (genetic mutation). If a family has an altered gene, usually several relatives on the same side of the family are diagnosed with ovarian cancer or related cancers, such as breast, bowel or womb cancer. People in the family may also be diagnosed with cancers at a particularly young age. Doctors are most interested in the history of cancer in your close relatives (first-degree relatives and second-degree relatives). First-degree relatives are your parents, brothers, sisters and children. Second-degree relatives are your grandparents, grandchildren, aunts, uncles, nieces and nephews.
If any of the following are present on one side of your family (either your father’s or your mother’s side), it’s possible that there may be an inherited faulty gene that increases your risk of developing ovarian cancer:
- Ovarian cancer in at least two close relatives, where at least one is a first-degree relative.
- Ovarian cancer in a first-degree relative and a first- or second-degree relative diagnosed with breast cancer under the age of 50 (or both cancers in the same person).
- Ovarian cancer in a first-degree relative and two relatives (who are first-degree relatives of each other) diagnosed with breast cancer before they reached an average age of 60.
- Ovarian cancer in one close relative and colon (bowel) and/or womb (endometrial) cancers in three relatives.
We have more information available about cancer genetics.
The symptoms of ovarian cancer can be similar to symptoms caused by other, more common, conditions.
These conditions may include:
- feeling bloated (having a swollen tummy)
- feeling full quickly and/or loss of appetite
- pain or discomfort in the lower tummy area and/or back
- needing to pass urine more often or more urgently (feeling like you can’t hold on)
- changes in bowel habits (diarrhea or constipation)
- pain during sex
- weight gain or weight loss
- unexplained or extreme tiredness
Because the symptoms of ovarian cancer can be mistaken for symptoms of other non-cancerous conditions, there can be sometimes be a delay in diagnosis.
It is recommended that if a woman has the following symptoms and they last for a month or more, or occur on at least 12 days in a month, she should see her PCP to be checked for ovarian cancer:
- Feeling bloated (having a swollen tummy).
- Feeling full quickly and/or loss of appetite.
- Pain or discomfort in the lower tummy area and/or back.
- Needing to pass urine more often or more urgently (feeling like she can’t hold on).
If a woman over 50 develops symptoms similar to irritable bowel syndrome (IBS), such as bloating and changes in bowel habit, she should be offered tests by her PCP to check for ovarian cancer. This is because it’s unusual for a woman of this age to develop IBS if she hasn’t had it before.
Most women with the symptoms listed here won’t have ovarian cancer, but it’s important to get them checked out.