UC Davis researchers report advance that may lead to much-needed test for ovarian cancer

UC Davis team has identified new biomarker test for the disease

A team of UC Davis Cancer Center researchers has identified a biomarker profile test for ovarian cancer, an advance that may lead to an early test for the disease.

The biomarkers were present in blood samples from ovarian cancer patients but not in samples from healthy patients, the researchers report in the July 7 issue of the Journal of Proteome Research.

“We need to study larger numbers of blood samples, but we are hopeful this approach will lead to a test that will allow doctors to detect ovarian cancer early, when it is most curable,” said Gary Leiserowitz, professor and chief of gynecologic oncology at UC Davis Cancer Center and one of the study authors.

“So far, this method has been highly accurate,” said Carlito Lebrilla, professor of chemistry and senior author of the study.

Because the early symptoms of ovarian cancer are typically subtle and nonspecific, two-thirds of women with the illness are diagnosed only after the disease has spread to other organs. As a result, ovarian cancer has the highest mortality rate of any gynecologic malignancy.

One blood test for ovarian cancer is commercially available, but it is too unreliable to be useful as a screening tool for early diagnosis. That test, which measures levels of a tumor marker known as CA-125, is used primarily to help monitor treatment response and disease recurrence in patients with diagnosed ovarian cancer.

In their new study, the UC Davis scientists report using an emerging science known as glycomics to identify changes in the sugars attached to cellular proteins that appear to be characteristic of ovarian cancer. These altered sugars can be detected in the blood of ovarian cancer patients. The profile of sugars is different from that seen in healthy women.

The researchers are planning further studies involving blood samples from a larger number of patients and healthy controls. They hope to isolate those biomarkers that will best detect early ovarian cancer.

According to the American Cancer Society, an estimated 20,180 women will be diagnosed with ovarian cancer in the United States this year and only about 45 percent will survive five years.

“If we had an effective early detection tool that would allow us to routinely diagnose ovarian cancer at its earliest stage, stage I, we would expect survival for this disease to be 85 to 95 percent — in the same range as for other stage I cancers,” Leiserowitz said. “It is imperative that we develop an early detection tool for this disease.”

UC Davis Cancer Center is the nation’s 61st National Cancer Institute-designated cancer center. Its cancer research program is comprised of more than 180 scientists from more than a dozen schools, departments and programs across three campuses: the UC Davis campus in Davis, Calif., the UC Davis Medical Center campus in Sacramento, and the Lawrence Livermore National Laboratory in Livermore, Calif.