Scientists have identified a chemical in the blood that may indicate early stage ovarian cancer. If confirmed by larger studies, the finding may provide a way to detect ovarian cancer when the disease is most treatable.
Because ovarian cancer usually escapes detection until it has spread beyond the ovaries, it is the deadliest of all gynecological cancers. The 5-year survival rate with advanced disease is no more than 15%. But if the cancer can be detected while it is still localized, nearly 90% of patients live longer than 5 years. A possible early warning sign occurred to cancer biologist Yan Xu at the Cleveland Clinic Foundation while she was studying lysophosphatidic acid (LPA), a blood chemical that stimulates the growth of ovarian cancer cells in the lab. Since some patients with advanced ovarian cancer have elevated LPA levels, Xu wondered if women in the early stage of the disease might also have high LPA levels.
Xu and her colleagues at the Cleveland Clinic Foundation recruited 84 women with various gynecological cancers and tested their LPA levels. They report in tomorrow's issue of the Journal of the American Medical Association that all the women with advanced ovarian cancer and 95% of women with other gynecological cancers had blood levels of LPA higher than their healthy counterparts. Especially noteworthy was the finding that nine out of 10 women with documented early stage ovarian cancer also had this marker elevated. "If we have a 90% probability of picking up early stages of the disease, then you can argue that this would be a good screening test," says team member Maurie Markman, a medical oncologist. First, however, many more women with early stage ovarian cancer must be tested to determine whether it would be useful to screen healthy women and those at high risk for developing ovarian cancer.
Other experts view these findings with cautious optimism. James Roberts, a gynecologic oncologist at the Stanford University School of Medicine, would like to see a simpler test tried out with more patients. By linking high LPA levels to gynecological cancers, especially stage one ovarian cancer, "you'll have a much more curable disease."