New test to help early diagnosis of ovarian cancer

Opening up the possibility for early diagnosis of ovarian cancer, scientists have identified genetic material that distinguishes its cells from normal cells. These genetic material includes six mRNA isoforms produced by ovarian cancer cells but not normal cells could be used to diagnose early-stage ovarian cancer.

Ovarian cancer is very difficult to diagnose and treat, making it an especially fatal disease. "We were inspired by many studies aimed at using DNA to detect cancer," said first author Christian Barrett at University of California, San Diego School of Medicine and Moores Cancer Center.

"But we wondered if we could instead develop an ovarian cancer detection test based on tumour-specific mRNA that has disseminated from cancer cells to the cervix and can be collected during a routine Pap test," Barrett said.

They identified six mRNA isoform molecules that have the tumour specificity required for an early detection diagnostic of ovarian cancer. In contrast to DNA, mRNAs are complementary copies of the genes and carry the recipe for every protein that the cell will produce from the nucleus to the cytoplasm.

Whereas a cancer cell might harbour just one or a few copies of a DNA mutation, but mRNA variants can occur in hundreds to thousands of copies per cell. For the study, the team analyzed mRNA sequence data from 296 ovarian cancers and 1,839 normal tissue samples.

"Our experimental findings were made in a laboratory and were performed on ovarian cancer cells from cell lines," said study co-author Cheryl Saenz, a clinical professor of reproductive medicine at University of California.

(The study was outlined in the Proceedings of the National Academy of Sciences)