Ovarian Cancer Overview

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Causes, Risk Factors, and Prevention TOPICS

What are the risk factors for ovarian cancer?

A risk factor is something that affects a person’s chance of getting a disease. Different cancers have different risk factors. Some risk factors, such as smoking, can be changed. Others, like a person’s age or race, can’t be changed.

But risk factors don’t tell us everything. Having a risk factor, or even many risk factors, does not mean that you will get the disease. And many people who get the disease may not have had any known risk factors. Even if a woman with ovarian cancer has a risk factor, it is very hard to know what part that risk factor might have played in the development of the cancer.

Risk factors for ovarian cancer

Age

The risk of ovarian cancer goes up with age. Half of all these cancers are found in women over the age of 63.

Obesity

Obese women (those with a body mass index of at least 30) have a higher risk of developing ovarian cancer.

Pregnancy

Women who have been pregnant and carried the baby full-term have a lower risk of ovarian cancer than women who have not. The risk goes down with each full- term pregnancy. Breastfeeding may lower the risk even further.

Birth control

Women who have used birth control pills have a lower risk of ovarian cancer. The lower risk is seen after only 3 to 6 months of using the pill, and the risk is lower the longer the pills are used. This lower risk goes on for many years after the pill is stopped.

A recent study found that the women who used the contraceptive injection depot medroxyprogesterone acetate (DMPA or Depo-Provera CI®) had a lower risk of ovarian cancer. The risk was even lower if the women had used it for 3 or more years.

Female surgery

Having your “tubes tied” (tubal ligation) may reduce the chance of getting ovarian cancer. Removal of the uterus without removing the ovaries (a hysterectomy) also seems to reduce the risk of getting ovarian cancer.

Fertility drugs

Some studies have found that use of the fertility drug clomiphene citrate (Clomid®) for longer than one year, especially if no pregnancy took place, may increase the risk of low malignant potential tumors. But not having been pregnant also increases the risk, even without the use of fertility drugs. Research in this area is now going on. If you are taking this drug, you should talk to your doctor about the possible risks.

Male hormones

Androgens are male hormones. In some studies, women who took androgens had a higher risk of ovarian cancer. Further studies are planned to look at this.

Estrogen therapy and hormone therapy

Some recent studies suggest women using estrogens after change of life (menopause) have an increased risk of ovarian cancer. The risk seems to be higher in women taking estrogen alone (without progesterone) for many years (at least 5 or 10). The increased risk is less certain for women taking both estrogen and progesterone.

Family history of ovarian cancer, breast cancer, or colorectal cancer

Ovarian cancer can run in families. Your ovarian cancer risk is higher if your mother, sister, or daughter has (or had) ovarian cancer. The risk gets higher the more relatives you have with ovarian cancer. Increased risk for ovarian cancer does not have to come from your mother’s side of the family − it also can come from your father’s side.

Having a family member with breast cancer can increase your risk of ovarian cancer. And women who have colon cancer in their families may have a higher risk of developing ovarian cancer, too.

Many cases of familial epithelial ovarian cancer are caused by inherited gene mutations that can be identified by genetic testing. Please see the section, “More information about ovarian cancer” to learn about genetic counseling and testing.

Genetic changes and syndromes

Certain inherited gene changes (mutations) can increase the risk of ovarian cancer. These include changes in the BRCA1 and BRCA2 genes. If you have inherited a mutation of one of these genes from either parent, your chances of getting breast and/or ovarian cancer increase.

In some cancers, gene mutations may result from radiation or cancer-causing chemicals. But so far, studies haven't been able to link any single chemical in the environment or in our diets to mutations that cause ovarian cancer.

There are also several syndromes that increase the risk of ovarian cancer. A syndrome is a group of signs and symptoms that together point to a certain disorder or disease. The following syndromes increase the risk of ovarian cancer:

  • Cowden's disease
  • Hereditary nonpolyposis colon cancer (also called Lynch syndrome)
  • Peutz-Jeghers syndrome
  • MUTYH-associated polyposis

Breast cancer

Women who have had breast cancer also have a higher risk of ovarian cancer. The risk is even higher in women who have had breast cancer and also have a family history of breast cancer.

Talcum powder

Some studies have shown a slight increase in ovarian cancer risk among women who used talcum powder on the genital area. Asbestos in the powder may explain the link. But these products have been free of asbestos for more than 20 years. Proving the safety of newer products will mean further studies of women who have used them for many years.

Diet

A study of women who followed a low-fat diet for at least 4 years showed they had a lower risk of ovarian cancer. Some studies have shown a reduced rate of ovarian cancer in women who ate a diet high in vegetables, but other studies disagree.

The American Cancer Society recommends eating at least 2 ½ cups of fruits and vegetables every day, as well as several servings of whole grain foods from plant sources such as breads, cereals, grain products, rice, pasta, or beans. Limit the amount of red meat and processed meats you eat. A healthy diet can help prevent other diseases, too, including some other types of cancer.

Smoking and alcohol use

Smoking is linked to an increased risk for a certain type of ovarian cancer (called mucinous), but not other types.

Drinking alcohol is not linked to ovarian cancer risk.


Last Medical Review: 04/22/2013
Last Revised: 02/06/2014