CA-125 screening for ovarian cancer may save lives

New results from the world's largest ovarian cancer screening study demonstrate that a strategy that starts with a simple blood test called CA-125 may result in fewer ovarian cancer deaths. That's because the CA-125-based strategy identifies more women with ovarian cancer in earlier stages.

While the study is a significant step forward for early detection, it may be years before ovarian cancer screening guidelines change. More research needs to be done before the blood test is used as screening for all women, says Karen Lu, M.D., Gynecologic Oncology and Reproductive Medicine chair.

"This study shows that we may actually decrease deaths from a highly lethal cancer, but it's a different question as to whether we're ready to recommend that all women get screened for ovarian cancer," Lu says. "I think that we're close, but we need a few more years of results before we say that every woman should have it."

How does the ovarian cancer CA-125 screening strategy work?
The screening strategy asks women to have a yearly CA-125 blood test. Then, the strategy relies on a scientific method called the Risk of Ovarian Cancer Algorithm (ROCA) to determine if women should go on to have an ultrasound and potentially surgery.

MD Anderson has been researching CA-125, for several decades. In the 1980s, Robert Bast, M.D., vice president for translational research at MD Anderson, discovered that certain levels of the CA-125 protein in blood could indicate ovarian cancer recurrence. A smaller ovarian cancer screening study using CA-125 and ROCA has been on-going at MD Anderson.

The latest study, the UK Collaborative Trial of Ovarian Cancer Screening, is the world's largest study on ovarian cancer early detection. It was designed to determine whether screening saves lives. More than 200,000 women participated in the study.

The study showed that the CA-125-based screening strategy results in earlier stage ovarian cancers being detected. The study results showed that the strategy may reduce the number of ovarian cancer deaths by 20%. This means about 15 ovarian cancer deaths could be prevented for every 10,000 women who receive annual screening for seven to 11 years.

Three more years of follow-up research are necessary to confirm these findings. In addition to the benefits of screening, harms also need to be considered. For every three women who had surgery, one had ovarian cancer and two women did not.

Who needs ovarian cancer screening?
Not all women need screening for ovarian cancer. Currently, yearly or twice-a-year screening is recommended for women younger than age 40 who have the BRCA1 or BRCA2 genetic mutations, which increase a person's chances of developing breast and ovarian cancer. This screening includes the CA-125 blood test and a transvaginal ultrasound. After age 40, Dr. Lu recommends that women who are at high risk for ovarian cancer have their fallopian tubes and ovaries removed to prevent them from developing ovarian cancer.

If you're concerned that you may be at risk for ovarian cancer, talk to your doctor about your personal and family cancer history.

Ovarian cancer is one of the diseases MD Anderson is focusing on as part of our Moon Shots Program to dramatically reduce cancer deaths. Learn more about our Breast and Ovarian Cancers Moon Shot.