Risk factors

Everyone born with ovaries has a degree of risk for ovarian cancer. Some people have higher risk than others based on a number of factors.

These factors can increase a person’s risk of ovarian cancer:

Age: Risk for ovarian cancer increases as a person ages. Because as we age, cells become damaged, making it more likely for cancer to develop. This disease is more common between the ages of 50 to 79.
Genetic mutations*: Genetic mutations occur when a gene is altered and stops working as it should. Inheriting certain genetic mutations, such as BRCA gene mutations, increases a person’s risk of ovarian cancer and other diseases. For information on specific genetic mutations, please see below.
Ethnicity*: Some genetic mutations are more common among certain ethnic groups. For instance, those of Ashkenazi Jewish or French-Canadian descent have an increased risk for ovarian cancer.
Family history of certain cancers*: Risk is higher if there is a family history of ovarian, breast, prostate, pancreatic, endometrial, or colorectal cancer on the mother’s or father’s side of the family.
Use of talc powder: Some research suggests that if talc particles travel through the vagina, uterus, and fallopian tubes, it may contribute to cancer in the ovaries. According to Health Canada, use of talc powder in the female genital area can increase risk of ovarian cancer.
Endometriosis: Risk for specific types of ovarian cancer may be higher if there is a history of endometriosis, which is a benign condition associated with growth of endometrial (lining of the uterus) tissue inside the ovary. However, reasons for the correlation have not been confirmed.

* If one or more of the risk factors marked with an asterisk applies to you, visit the prevention page to find out how you can stop ovarian cancer before it starts.

These factors can decrease a person’s risk of ovarian cancer:

Gynecological surgery: Surgical removal of the ovaries and/or fallopian tubes reduces risk of ovarian cancer. This is because many ovarian cancers originate in the fallopian tubes and quickly spreads to the ovary and surrounding organs. However, ovarian cancer can still develop after the ovaries and fallopian tubes are removed if cancer cells spread into other areas prior to surgery.
Reproductive history and use of oral contraceptives: The number of times a person ovulates correlates with their risk for ovarian cancer. Interrupting ovulation; by giving birth, breastfeeding, or using oral contraceptives; reduces risk of this disease.

Genetic Mutations

BRCA1 and BRCA2 (Breast Cancer 1 and 2)

The BRCA 1 and BRCA 2 genes are involved in most cases of hereditary ovarian cancer. Everyone has BRCA 1 and BRCA 2 genes that are known as tumour suppressors. Mutation of these genes has been linked to hereditary breast and ovarian cancer.

Women who test positive for the BRCA 1 and BRCA 2 gene mutation are at increased risk for both ovarian and breast cancer. Often with the BRCA1 and BRCA2 mutation, breast cancer appears at younger ages and increases the risk of a second cancer.

Populations at increased risk for having the BRCA1 and BRCA2 mutations are:

Women of Ashkenazi Jewish descent (risk is 1 in 40)
French Canadians of certain ancestry may be at increased risk
Icelandic and Dutch populations

Other gene mutations

Some incidents of ovarian cancer are related to other gene mutations, such as the Lynch Syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC).

Populations at risk for having this mutation have:

Three or more relatives with an Lynch syndrome-related cancer (colorectal, endometrial, small bower, ureter or renal pelvic, ovarian); and one relative must be a first-degree relative (parent, brother, sister, or child) of the other two;
At least two generations with cancer (such as a parent and child);
One or more cases of cancer diagnosed younger than age 50;

If you have a family history, it is important that you let your doctor know.

Ask for a referral to a genetic counsellor. This is an important step to help you understand the risks and benefits of genetic testing.

Also refer to: Canadian Association of Genetic Counsellors