Q: I'm 55 years old and I'll be seeing my doctor soon for a checkup. Should she do any special tests to screen for ovarian cancer? A: The current tests available to us are not “routine,” unless you have a family history of ovarian cancer or have several relatives with early-onset breast cancer.
Unfortunately, 75 percent of women with ovarian cancer are diagnosed after the disease has reached an advanced stage. So clearly, if I (and every physician out there) was able to offer a cost-effective screening test with good sensitivity and high specificity to our patients (in other words, a test without many false negatives or positives), we would. But so far no such tests exist.Researchers are looking at protein array (pattern) testing, which is a search for very specific molecular protein patterns found to be associated with ovarian cancer. Once identified, they then want to use a computerized method to detect these proteins from billions of other protein patterns in the blood samples of our population. This is a huge undertaking; it’s extremely complicated to isolate these protein arrays and even harder to find them (think needle in a haystack) while screening blood samples from a large population. Current technology may allow this difficult task to be accomplished in the near future ... but we then have to wait for studies to see if the screening can be done with reproducible and correct results in first a high-risk group of women and then everyone else.
Until then, there are two ways to test for ovarian cancer (aside from surgery). The first test is a pelvic ultrasound that looks for abnormal cysts or tumors on the ovary. The second is a blood test that measures levels of CA-125, a protein that may be produced by tumors of the ovary, stomach and intestines. However, this particular protein may also be increased in the blood with fibroids, endometriosis, or for no reason at all (it’s elevated in 1 percent of healthy women). To add to this test's poor predictable nature of occult (hidden) ovarian cancer, CA-125 is elevated in only 50 percent of women with early ovarian cancer. This protein is, however, most likely elevated in late-stage cancers and a reduction of the levels is an important indicator of successful therapy.The efficacy of screening large populations of women with both ultrasound and CA-125 to allow for the early detection of ovarian cancer (thereby reducing the mortality from this disease) was carried out in 39,115 women between 1993 and 2001. The results were not favorable for using these tests for ovarian screening. They were as follows:
- 1,338 women had an abnormal vaginal ultrasound scans
- 402 women had elevated CA-125 levels
- 34 women had abnormalities in both tests
- 29 women in all the women had ovarian cancer; 20 of these cancers were invasive
These results were not considered by statisticians to meet the "we should routinely screen with these tests" criteria. For a test to be cost-effective (in simple terms, worth doing on a large basis), it should have a positive predictive value of 10 percent. This means that 10 surgeries are necessary to detect one cancer. In this study the positive predictive value was 4 percent for an abnormal CA-125 result and 1.6 percent for an abnormal transvaginal ultrasound. When both tests were abnormal, this value was 23.5 percent (meaning approximately four surgeries were needed to detect one cancer), but in women where one or both tests were not abnormal, 12 out of 20 invasive cancers were missed. That's an awful lot of cancers to miss in women who were reassured that their tests were fine.
This study is ongoing and perhaps in the future there will be more definitive and conclusive results that change the current guidelines set forth by the U.S. Preventive Services Task Force. In the meantime, they state that “routine screening for ovarian cancer by ultrasound, the measurement of serum tumor markers, or pelvic examination is not recommended.” This is not to say that pelvic exams are not appropriate while getting that all important Pap smear or to assess any other gynecologic problem.
Dr. Reichman’s Bottom Line: According to current guidelines, there is no need for your doctor to perform specific ovarian cancer screening tests as part of your routine checkup.
Dr. Judith Reichman, the TODAY show’s medical contributor on women’s health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, “Slow Your Clock Down: The Complete Guide to a Healthy, Younger You,” which is now available in paperback. It is published by William Morrow, a division of .
PLEASE NOTE: The information in this column should not be construed as providing specific medical advice, but rather to offer readers information to better understand their lives and health. It is not intended to provide an alternative to professional treatment or to replace the services of a physician.