Breakthrough in detecting ovarian cancer?

SEATTLE (MCT) — Researchers have taken a small but potentially significant step closer to early detection of ovarian cancer, a sneaky disease that's often diagnosed too late for effective treatment.

Various cancer "biomarkers" begin to show up in blood tests long before symptoms occur, but aren't accurately predictive until later, when tumors likely have reached an advanced stage, Fred Hutchinson Cancer Research Center researchers have found.

The study, published Wednesday in the Journal of the National Cancer Institute, was headed by Garnet Anderson and Nicole Urban of the Hutchinson center's Division of Public Health Sciences.

"What this study did was move one step closer to early detection," said Anderson, a biostatistician. "It gives us an idea of where we want to go but doesn't solve the problem."

For several years, the ovarian cancer researchers have focused on biomarkers, proteins secreted by tumors, hoping to find one or more that show up early in the disease's progress. Now, most ovarian cancer cases aren't diagnosed in the early stages, when treatment has a high cure rate.

The researchers analyzed stored blood samples collected over many years for a previous large research study involving women smokers. Ultimately, 34 of those women were diagnosed with ovarian cancer. Looking at the blood samples, taken periodically up to 18 years before diagnosis, the researchers found that three of six biomarkers, including one known as CA125, increased in cancer patients up to three years before diagnosis, compared to patients without ovarian cancer.

But at that early stage, the levels weren't high enough to accurately predict the disease, researchers found. A high degree of accuracy is required for such tests, the researchers wrote, "because a definitive diagnosis requires surgery."

Only at a year or less before the women were diagnosed with ovarian cancer did the blood levels of the biomarkers become more accurate. While the researchers said they didn't know whether that was sufficient time to help women live longer, a local cancer authority who was not involved in the study said any lead time may help.

"Finding ovarian cancer a year earlier could have a significant impact," said Dr. Barbara Goff, a surgeon and director of gynecologic oncology at the University of Washington. "Even three months makes a huge difference when you're going into someone's belly."