Does family history affect ovarian cancer risk?

Yes. The National Cancer Institute states that "women who have a family history of ovarian cancer are at an increased risk of ovarian cancer." The clearest signal is a first-degree relative: a mother, daughter, or sister.

Scale matters here in both directions. NCI reports that "hereditary ovarian cancer makes up about 20% of all cases of ovarian cancer." So family history explains roughly one case in five. It does not explain the other four. A woman with no family history at all can still develop ovarian cancer, and most who do have exactly that.

What is actually being inherited

Not the cancer. A gene change. NCI names inherited changes in BRCA1 and BRCA2 as the main ones. It also names Lynch syndrome, once called hereditary nonpolyposis colorectal cancer. NCI adds that "fallopian tube cancer and peritoneal cancer may also be caused by certain inherited gene mutations."

The size of the effect is worth seeing in plain numbers. NCI's BRCA fact sheet reports that "about 1.1% of women in the general population will develop ovarian cancer." Among women who inherit a harmful BRCA1 change, that figure is "about 39%–58%." For BRCA2 it is "13%–29%." The same variants carry breast cancer risk of more than 60%, against about 13% in the general population.

Those numbers explain why a positive test changes several decisions at once, not just one.

When a family history is worth acting on

NCI lists the patterns that should prompt a talk about testing. One is a known BRCA variant in the family. One is Ashkenazi Jewish heritage. The rest are a personal or family history of breast cancer at age 50 or younger, ovarian cancer, male breast cancer, pancreatic cancer, or high-risk prostate cancer.

Notice how many of those are not ovarian cancer. These genes cause a cluster of cancers, so the relevant history is wider than one disease.

The step people skip, and the one they should not

Here is the part that surprises women who go looking for reassurance. There is no screening test for ovarian cancer that works in the general population. The US Preventive Services Task Force "recommends against screening for ovarian cancer in asymptomatic women." It grades that advice D. A grade D means the Task Force judged the harms to outweigh the benefits.

That recommendation has a deliberate hole in it. It applies only to women "not known to have a high-risk hereditary cancer syndrome." Women with such a syndrome are excluded and handled separately, and USPSTF "recommends that women with a family history indicating they are at risk for a deleterious gene mutation (BRCA1 or BRCA2) be referred for genetic counseling and, if indicated, genetic testing."

So the useful request is not a scan. It is an assessment. Genetic counseling works out whether your family pattern warrants testing. It also covers which test to run, and what a result would mean for you and for your relatives.

If testing does find a variant, the options are real. One is closer monitoring. Another is risk-reducing surgery to remove the ovaries and fallopian tubes. NCI describes that surgery as lowering ovarian risk, and possibly breast cancer risk too.

Before that appointment, build the family tree. Write down who had cancer and which cancer. Add the age at diagnosis, and which side of the family they sat on. Include the men. That single page does more to guide the conversation than any test ordered without it.