Issue of
September 23, 1998

Early warning sign of ovarian cancer?

BY MITCH LESLIE

Ovarian cancer is the deadliest gynecologic cancer because of the difficulty of early diagnosis. Last month, researchers from the Cleveland Clinic Foundation described a blood chemical called LPA that they believe may serve as an early warning sign of the disease. Before a screening test can be developed, however, the result needs to be confirmed in a larger study and the method should be simplified for widespread use, cautioned Stanford gynecologic oncologist James Roberts, MD, in an accompanying editorial.

A diagnostic test could save thousands of lives a year, noted Roberts, a professor of gyn/ob, in the Aug. 26 Journal of the American Medical Association. Ninety percent of women diagnosed with early-stage ovarian cancer live at least five years, compared with only 15 percent of those diagnosed with advanced disease. But the 20-year search for a telltale biochemical sign of ovarian cancer has yet to produce a usable diagnostic test, Roberts said.

The Cleveland team focused on LPA (lysophosphatidic acid) as a possible "biomarker" after observing that it stimulates ovarian cancer cells to multiply. They measured high levels of LPA in nine out of 10 patients with early-stage ovarian cancer and in all 24 patients with later-stage cancers. But women with other gynecologic cancers also had high LPA levels, the team found. This lack of specificity casts doubt on LPA's usefulness as an indicator of ovarian cancer, Roberts warned.

While the chemical may not pan out as a specific diagnostic biomarker, it could offer new insights into various gynecologic cancers, he suggested. "The consistent presence of LPA in serum of women with a variety of gynecologic cancers suggests that the importance of this chemical might not be as a biomarker but rather as a clue to advancing the understanding of the molecular biology of gynecologic cancer," Roberts wrote.