Cause
The cause of
ovarian cancer is not known. Genetics are a risk
factor for some women. A
family
history
of ovarian or breast cancer is found in 10% to 20% of women with
ovarian cancer.1 In general, fewer than 2 in 100 women
(less than 2%) will get ovarian cancer in their lifetime. That risk goes up to
4 or 5 in 100 if one family member has had ovarian cancer, and 7 in 100 if two
relatives have had it. But if at least two first-degree relatives (meaning
mother, sister, or daughter) have had ovarian cancer, the risk is 25 to 50 in
100 (25% to 50%).2
Women who inherit changes (genetic
mutations) in the
BRCA1 and BRCA2 genes have a higher chance of
developing ovarian cancer and breast cancer. Women who inherit the gene change
in BRCA1 have a lifetime chance of 20 to 60 out of 100 of getting ovarian
cancer. For women who inherit the gene change in BRCA2, the lifetime chance is
10 to 35 out of 100.3
You have a higher chance of developing ovarian cancer if
you:
- Are unable to become pregnant (infertility).
- Have never had a baby.
- Have not used hormonal
birth control methods. Hormonal methods change the
normal cycle of the female hormones,
estrogen and
progesterone, so ovulation does not occur each
month.
If you have a strong family history of ovarian or breast cancer,
you may want to talk with your doctor or a
genetic counselor about having a blood test to look
for BRCA1 and BRCA2 gene changes. Women who inherit these changes in one or
both of these genes have a higher chance of developing ovarian cancer, breast
cancer, or both.