Ovarian Cancer Risk Factors

Most women with ovarian cancer do not have any known risk factors. However, there are several factors that may increase the risk of ovarian cancer. Having one or more of these risks does not necessarily mean the development of ovarian cancer, but the risk may be higher compared to the average woman.

  • Hormone replacement therapy (HRT)

    Women who use menopausal hormone therapy are at an increased risk for ovarian cancer. Recent studies indicate that five or more years of estrogen plus progestin use significantly increases the risk of ovarian cancer in women who have not had a hysterectomy. Ten or more years of estrogen alone among women who had a hysterectomy increased the risk of developing ovarian cancer. HRT is usually prescribed to alleviate symptoms associated with menopause (such as hot flashes, night sweats, sleeplessness and vaginal dryness) that occur as the body adjusts to decreased levels of estrogen. HRT usually involves treatment with either estrogen alone or a combination of estrogen with progesterone or progestin. Estrogen alone is usually prescribed only for women who have had a hysterectomy. A combination of estrogen plus progestin is typically recommended for women who have not had a hysterectomy.

  • Genetics

    The most significant risk factor is an inherited genetic mutation in the BRCA1 or BRCA2 genes. These genes are responsible for about five percent to 10 percent of all ovarian cancers. Women of Ashkenazi Jewish descent are at higher risk of carrying BRCA1 or BRCA2 mutations; however, the risk of having the mutations is not exclusive to this group of women. Another known genetic link to ovarian cancer is an inherited syndrome called hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch Syndrome. People from families with HNPCC have an increased risk of getting several cancers, primarily cancer of the colon, uterine lining, ovary, stomach, small intestine, biliary tract and urinary tract. Women with HNPCC have about a 12 percent lifetime risk for ovarian cancer. Ovarian cancer can occur in more than one family member independent of a known inherited gene mutation. Woman who have one first-degree relative (such as their mother) with ovarian cancer but no known genetic mutation are still at an increased risk of developing the disease. Their lifetime risk is five percent verses the 1.44 percent rate of risk of women in the general public. 

  • Increasing age

    Most ovarian cancer cases develop after menopause. About 69 percent of women diagnosed are age 55 or older. The median age (the age at which half of all reported cases were older and half were younger) at diagnosis is 63 years. A woman’s risk of ovarian cancer increases with age through her late 70s. Although most cases of ovarian cancer are diagnosed in women over age 55, the disease can occur in younger women. 

  • Reproductive history and infertility

    There seems to be a relationship between the number of menstrual cycles in a woman’s lifetime and her risk of developing ovarian cancer. Women are at increased risk for ovarian cancer if they:

    • Started menstruating at an early age (before age 12)
    • had no children
    • had their first child after age 30
    • and/or experienced menopause after age 50

    In addition, research indicates that infertility increases the risk of ovarian cancer, even without use of fertility drugs. The risk appears to be highest for women with unexplained infertility and for women with infertility who never conceived.

  • Obesity

    The research is inconclusive. Recent studies suggest that obesity in early adulthood is associated with an increased risk of ovarian cancer. There is also a higher rate of death from ovarian cancer in obese women. Increasingly, findings point to a link between obesity and cancer.

This information has been taken with permission from the Ovarian Cancer National Alliance, http://ovariancancer.org.


We are a registered 501(c)(3) Non-Profit Corporation. EIN: 20-2558493 Copyright © 2005-2017 Ovarian Cancer Alliance of Oregon and Southwest Washington. All rights reserved.
   Site Design by Lee Wallat Design         

Powered by Wild Apricot Membership Software