Epithelial ovarian cancer is the leading cause of gynecologic cancer deaths in the United States and three times more lethal than breast cancer. It is usually not diagnosed until its advanced stages and has come to be known as the "silent killer."
"Early diagnosis can help prolong or save lives, but clinicians currently have no sensitive screening method because the disease shows few symptoms," said the study's lead author Gil Mor, M.D., associate professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine. Mor is also affiliated with the Yale Cancer Center.
Mor conducted the research with David Ward, deputy director of the Nevada Cancer Institute. They developed and tested a new blood test for ovarian cancer based on four proteins: leptin, prolactin, osteopontin and insulin-like growth factor-II. If the level of two or more of these biomarkers for a patient falls within a certain warning area, the test will predict that she has cancer. In a test group of over 200 ovarian cancer patients and healthy women, the test showed 95 percent sensitivity (fraction correctly diagnosed with cancer) and 95 percent specificity (fraction correctly diagnosed as cancer-free).
Each of the proteins had been previously suggested as a good cancer biomarker, though not as a set. In this study, no single protein could completely distinguish the cancer patients from the healthy controls.
Other authors on the study are Irene Visintin, Yinglei Lai, Hongyu Zhao, Peter Schwartz, Thomas Rutherford, Luo Yue and Patricia Bray-Ward.
Citation: PNAS Vol. 102, No. 19, (May 10, 2005).
Proceedings of the National Academy of Sciences