Ovarian Cancer: Risk Factors

What is a risk factor?

A risk factor is anything that may increase your chance of having a disease. Risk factors for a certain type of cancer might include smoking, diet, family history, or many other things. The exact cause of someone’s cancer may not be known. But risk factors can make it more likely for a person to have cancer.

Things you should know about risk factors for cancer:

• Risk factors can increase a person's risk, but they do not necessarily cause the disease.

• Some people with 1 or more risk factors never develop cancer. Other people can develop cancer and have no risk factors.

• Some risk factors are very well known. But there is ongoing research about risk factors for many types of cancer.

Some risk factors, such as family history, may not be in your control. But others may be things you can change. Knowing the risk factors can help you make choices that might lower your risk. For example, if an unhealthy diet is a risk factor, you may choose to eat healthy foods. If excess weight is a risk factor, your healthcare provider may check your weight or help you lose weight.

Who is at risk for ovarian cancer?

There are many risk factors for ovarian cancer.

Age

A woman's risk for ovarian cancer rises with age. 

Obesity

Being obese means having a body mass index greater than 30. Obesity increases risk for ovarian cancer and increases the risk of dying from it.

Pregnancy history

Women who have never given birth have a slightly higher risk for ovarian cancer.

Use of estrogen replacement therapy

Women who have used menopausal estrogen replacement therapy (taking estrogen alone, without progesterone) for more than 10 years may have a slightly higher risk of ovarian cancer.

Family history and genetic syndromes

A mother or sister is considered a first-degree relative. If you have two or more first-degree relatives who have had ovarian cancer, this suggests that heredity may be a cause. If you have a family history of breast, ovarian, endometrial, or colon cancer, or genetic cancer syndromes such as Lynch syndrome, your family may have certain genetic mutations (such as BRCA genes) that increase the risk for ovarian cancer. These types of ovarian cancer account for about 5–10% of ovarian cancer cases. Syndromes passed in families and linked to increased risk include:

• Lynch syndrome or hereditary nonpolyposis colon cancer (HNPCC). This increases a woman's risk of having ovarian, uterine, colon, and other cancers at a much younger age than usual.

• Peutz-Jeghers syndrome (PJS). Thisis caused by a certain genetic mutation (gene STK11). It’s linked with a higher risk of ovarian, breast, uterine, and lung cancer.

• Gorlin syndrome or nevoid basal cell carcinoma syndrome (NBCCS). Women with NBCCS have an increased risk of non-cancerous fibrous tumors of the ovaries called fibromas. There is a slight risk that these fibromas could turn into ovarian cancer.

• Li-Fraumeni syndrome. Thisis linked with a slightly higher risk of ovarian cancer.

• Ataxia-telangiectasia. Thismay put women at a slightly higher risk for ovarian cancer.

• Cowden disease or PTEN tumor hamartoma syndrome. This is caused by inherited mutations in the PTEN gene. It mostly causes thyroid problems, thyroid cancer, and breast cancer. But it also increases the risk of ovarian cancer.

• MUTYH-associated polyposis. Thiscauses polyps in the colon and small intestine. It’s also linked with a high risk of colon cancer. It also puts people at a higher risk for other cancers, including cancers of the ovary and bladder.

Personal cancer history

A personal history of breast, uterine, rectum, or colon cancer puts you at a higher risk for ovarian cancer.

Use of fertility medicines

If you've used fertility medicines for more than a year, you may be at increased risk for ovarian cancer. However, studies show conflicting results on this link.

Endometriosis

If you have endometriosis, you may have a higher risk for ovarian cancer.

What are your risk factors?

Talk with your healthcare provider about your risk factors for ovarian cancer and what you can do about them.

If you’re concerned about your family's history of breast or ovarian cancer, talk with your healthcare provider about genetic counseling. If you have gene changes that put you at higher risk, you may want to discuss the possibility of having surgery to remove your ovaries and fallopian tubes to help lower your risk.

Ovarian cancer screening tests aren’t recommended. This is because current screening tests are not accurate enough to find ovarian cancer in most women. Regular pelvic exams are important, though. You can talk to your healthcare provider about using ultrasound to check your ovaries for changes if you’re at higher risk.

Regular blood tests for the antigen CA-125, a protein found in the cells of some kinds of ovarian cancer, may also be an option. This isn’t a perfect screening test because it’s not elevated in all women with ovarian cancer. If it is elevated, it doesn’t necessarily mean you have ovarian cancer.

Oral contraceptives, or birth control pills, may help lower the risk for some types of ovarian cancer. Women who take birth control pills for 5 years or more have about half the risk of ovarian cancer as women who never used them. But birth control pills can increase the risk for blood clots and stroke. They can also cause other side effects. Talk with your healthcare provider about birth control pills.