MONDAY, April 26, 2010 (HealthDay News) -- New understanding about the early stages of ovarian cancer may lead to the development of a new screening test for the cancer, U.S. researchers say.
In the study, scientists uncovered early tumors and precancerous lesions in inclusion cysts, which fold into the ovary from its surface.
"This is the first study giving very strong evidence that a substantial number of ovarian cancers arise in inclusion cysts and that there is indeed a precursor lesion that you can see, put your hands on, and give a name to," lead author Jeff Boyd, chief scientific officer at Fox Chase Cancer Center in Philadelphia, said in a news release. "Ovarian cancer most of the time seems to arise in simple inclusion cysts of the ovary, as opposed to the surface epithelium."
Boyd and his colleagues analyzed ovaries removed from women with BRCA gene mutations (who have a 40 percent lifetime risk of developing ovarian cancer) and from women with no known genetic risk factors for ovarian cancer.
In both groups of women, gene expression patterns in the cells of inclusion cysts were dramatically different than normal ovarian surface cells. For example, the cells of inclusion cysts had increased expression of genes that control cell division and chromosome movement. The researchers also found that cells from very early tumors and tumor precursor lesions frequently had extra chromosomes.
"Previous studies only looked at this at the morphologic level, looking at a piece of tissue under a microscope," Boyd said. "We did that but we also dissected away cells from normal ovaries and early-stage cancers, and did genetic analyses. We showed that you could follow progression from normal cells to the precursor lesion, which we call dysplasia, to the actual cancer, and see them adjacent to one another within an inclusion cyst."
With these findings, researchers can try to develop new screening tests to detect ovarian cancer in the earliest stages, when it is still treatable. Ovarian cancer kills nearly 15,000 women in the United States each year. Fewer than half of ovarian cancer patients live more than five years after diagnosis.
The study was published April 26 in the journal PLoS One.
The American Cancer Society has more about ovarian cancer.