Mayo Clinic researchers have developed the first liquid biopsies from blood tests and DNA sequencing that can detect ovarian cancer long before a tumor reappears.

The advance, reported by the Mayo Clinic Center for Individualized Medicine, provides a promising new way to monitor and treat recurrences of ovarian cancer — a hard-to-detect disease that claims many lives.

Lead researcher Dr. George Vasmatzis, Ph.D., of the Department of Laboratory Medicine and Pathology at Mayo Clinic, said the development could lead to earlier intervention and more effective, individualized treatment for the often-fatal condition.

“With liquid biopsies, we don’t have to wait for tumor growth to get a DNA sample,” said Vasmatzis. “This important discovery makes it possible for us detect recurrence of the disease earlier than other diagnostic methods. We can repeat liquid biopsies to monitor the progression of the cancer. That gives hope of a better treatment plan over time.”

To test the effectiveness of liquid biopsies, Mayo researchers tracked 10 patients in advanced stages of ovarian cancer. Investigators compared DNA from the liquid blood biopsies to DNA tissue samples from the patients’ tumors.

The findings, published in the journal Scientific Reports, indicated the biopsies effectively predicted which patients would experience recurrences.

Ovarian cancer has one of the highest death rates of all gynecological cancers, because the tumor often cannot be detected until the late stages. Most patients go into remission after initial treatment, but the tumor returns 75 percent of the time.

More than 21,000 women in the U.S. are diagnosed with ovarian cancer annually, and 14,000 women die of the disease in 2015.