Women with inherited gene mutations, a strong family history of ovarian or breast cancer, and those over 60 face the highest risk of ovarian cancer. The average woman has roughly a 1.4% lifetime chance of developing the disease, but certain genetic, reproductive, and medical factors can multiply that risk dramatically. About half of all ovarian cancer diagnoses occur in women aged 63 or older.
BRCA1 and BRCA2 Gene Mutations
Inherited mutations in the BRCA1 and BRCA2 genes represent the single strongest risk factor for ovarian cancer. Women with a BRCA1 mutation carry a lifetime risk of 39% to 44%, roughly 30 times higher than average. BRCA2 mutations carry a lifetime risk of 11% to 17%, still a significant increase.
Because of these dramatically elevated risks, national guidelines recommend that BRCA1 carriers discuss preventive surgical removal of the ovaries and fallopian tubes between ages 35 and 40, after completing childbearing. For BRCA2 carriers, that window shifts slightly later, between ages 40 and 45. This surgery reduces ovarian cancer risk by approximately 80% and also lowers breast cancer risk, since both genes are involved in both cancers.
Other Inherited Gene Mutations
BRCA1 and BRCA2 get the most attention, but several other genes also raise ovarian cancer risk. Mutations in three genes involved in DNA repair (known as BRIP1, RAD51C, and RAD51D) carry lifetime ovarian cancer risks of 6% to 15%. That’s lower than BRCA mutations but still several times higher than the general population’s risk. Women with these mutations tend to develop ovarian cancer later, with median diagnosis ages between 57 and 65, compared to 53 for BRCA1 carriers. Current evidence suggests preventive surgery can safely be delayed until age 45 to 50 for RAD51D carriers and possibly until 50 to 55 for BRIP1 and RAD51C carriers.
Lynch syndrome, caused by mutations in genes responsible for repairing errors during DNA copying, raises the lifetime risk of ovarian cancer to between 6.7% and 12%. Lynch syndrome is better known for its connection to colon and uterine cancers, so women diagnosed with it don’t always realize ovarian cancer is part of the picture.
Family History Without Known Mutations
Even without a confirmed genetic mutation, a strong family history of ovarian or breast cancer is a meaningful risk factor. A woman whose mother, sister, or daughter has had ovarian cancer faces roughly four times the average risk. If the affected relative is a grandmother, aunt, niece, or half-sibling, the risk is about two times higher.
Breast cancer in the family matters too. Having a mother, sister, or daughter with breast cancer increases ovarian cancer risk by about 70%. This overlap exists because the same gene mutations (particularly BRCA1 and BRCA2) drive both cancers. If your family has a pattern of breast or ovarian cancer, especially at younger ages, genetic counseling can help clarify whether testing makes sense.
Age
Ovarian cancer is primarily a disease of older women. Risk climbs steadily with age, and half of all diagnoses occur at age 63 or older. While younger women can develop ovarian cancer (particularly those with genetic mutations), the typical patient is postmenopausal. This is one reason the disease is so often caught late: symptoms like bloating, pelvic discomfort, and urinary changes overlap with common experiences of aging and menopause.
Endometriosis
Women with endometriosis have a substantially elevated risk. A large study published in JAMA found that endometriosis increased the overall risk of ovarian cancer by about four times. The risk varied by cancer subtype: it was highest for clear cell carcinoma (roughly 11 times the risk of women without endometriosis) and lowest, though still elevated, for high-grade serous ovarian cancer (about 2.7 times). Deep infiltrating endometriosis and ovarian endometriomas (cysts on the ovary) showed the strongest associations.
This doesn’t mean most women with endometriosis will develop ovarian cancer. The baseline risk is low, so even a fourfold increase keeps the absolute risk relatively small. But it does mean women with endometriosis, particularly severe forms, should be aware of the connection.
Reproductive and Hormonal Factors
Several factors related to ovulation, pregnancy, and hormone exposure influence ovarian cancer risk. The common thread is that more lifetime ovulations correlate with higher risk.
Women who have never given birth (nulliparity) face about a 24% higher overall risk of ovarian cancer than women who have had at least one child. That increase is more pronounced for certain subtypes: nearly 50% higher for endometrioid tumors and close to 70% higher for clear cell tumors. Each additional pregnancy appears to offer further protection.
Menopausal hormone therapy also shifts the odds. Women who use hormone therapy (either estrogen alone or combined estrogen-progestagen) have about a 37% increased risk of ovarian cancer while using it or within five years of stopping. The risk is concentrated in the two most common subtypes: serous and endometrioid tumors. Even a decade after stopping long-term hormone therapy, a small excess risk of about 25% persists for these tumor types.
On the protective side, oral contraceptive use significantly lowers risk. Five years of birth control pill use reduces ovarian cancer risk by roughly 40%, and the protection lasts for years after stopping. Breastfeeding also appears to offer some degree of protection, likely because it suppresses ovulation.
What High-Risk Women Can Do
If you have a known genetic mutation, your doctor will likely discuss a specific surveillance and prevention plan. For BRCA carriers, preventive removal of the ovaries and fallopian tubes remains the most effective option and is typically recommended at specific ages depending on the mutation. For moderate-risk gene mutations, the timing is later but the conversation is similar.
For women without genetic mutations but with a strong family history, genetic counseling is the logical first step. Many hereditary cancer syndromes go undetected for generations because no one in the family was tested. Identifying a mutation doesn’t just clarify your own risk; it gives family members the chance to be tested too.
Women with endometriosis, a history of hormone therapy use, or nulliparity generally don’t need aggressive screening, but understanding that these factors contribute to a modestly higher risk can inform conversations with a healthcare provider about symptoms worth investigating. There is no reliable screening test for ovarian cancer in average-risk women, which makes awareness of personal risk factors all the more important.