Risk factors are related to two major categories: menstrual cycles (ovulation) and family history. The more a woman ovulates (cycles) over her lifetime, the higher her risk of ovarian cancer. Thus starting her period (menarche) at a younger age, ending her periods (menopause) at a late age, and never getting pregnant (nulliparity) are all risk factors. It was once thought that infertility patients who underwent preparation for IVF (ovarian stimulation for in vitro fertilization) were at increased risk, but this has since been shown not to be the case in a large comprehensive review of the subject.
Approximately 15% of ovarian cancers are genetically related. Because of this, current guidelines suggest that all women with ovarian cancer should undergo testing for BRCA1 and BRCA2 gene changes (mutations). All patients with ovarian cancer will ideally discuss this topic with their doctor. These gene mutations can affect males as well as females. If a patient is positive for one of these, then her siblings and her children can be tested as well. Testing involves a simple blood test. The results of this test can greatly affect how family members are monitored for various cancers, including breast cancer, and family members of both sexes are encouraged to be tested.
BRCA1 and BRCA2 are genes that have been identified with hereditary cancer risk. BRCA1 and BRCA2 increase a woman's risk of breast cancer, for example. When compared with the general population risk (1.3% of women will develop ovarian cancer), women with BRCA1 and BRCA2 genetic mutations have a 39% (BRCA1) or 11%-17% (BRCA2) chance of developing ovarian cancer in their lifetime. Lynch syndrome (typically colon and uterine cancer), Li-Fraumeni syndrome, and Cowden's syndrome are other conditions associated with an increased risk of ovarian cancer but are less common.
The less common varieties of ovarian cancer (borderline, germ cell, and stromal tumors) have few definable risk factors. The germ cell tumors often seen at younger ages and are treated very differently both surgically and chemotherapeutically.