I'm a 54 year old woman and my grandmother had ovarian cancer. Am I at risk? I heard about a blood test to screen for ovarian cancer. Should I be tested?
Ovarian cancer is a fairly uncommon, but often deadly diagnosis; the lifetime risk for women in the U.S. is around 1 percent. Half the women diagnosed with ovarian cancer will die of their disease. Most (90%) of these cases are sporadic, meaning that they occur without a family history. As a general rule, if a woman has 2 or more first degree relatives with breast or ovarian cancer before age 50, genetic testing should be considered. In your situation with only one second degree relative affected, the increase in risk is likely minimal.
Why is ovarian cancer mortality so high?
Unfortunately, women with the disease tend to have few, if any symptoms until the cancer is far advanced. Symptoms that do occur are common in women without cancer--urinary frequency, constipation, pelvic pressure, and/or bloating. The best screening test in low-risk women continues to be an annual pelvic examination. I have had several women ask me about "the ovarian cancer blood test". This is an ovarian tumor marker known as CA-125 which is not used in routine screening for several reasons: it is elevated only when a cancer is more advanced; many other conditions raise CA-125 including endometriosis, liver disease, and diverticulitis; and there is no proven mortality benefit. Currently, the only role for CA-125 and ultrasound in screening for ovarian cancer is in women with a strongly positive family history or confirmed genetic mutation.
As for prevention, use of birth control pills and full-term pregnancies appear to significantly decrease the lifetime incidence of ovarian cancer, possibly by reducing the number of ovulation events over time. The risk can also be dramatically lowered by removing the ovaries surgically--an option to consider in higher-risk women after childbearing or at the time of hysterectomy for other reasons.
Your annual physical should always include a pelvic examination. If you have any questions about your family history or the role of further testing for ovarian cancer, consult your health care provider.