Ovarian cancer is difficult to diagnose

They have discovered a new marker for ovarian cancer, which may lead to a way to detect the disease with a simple blood test.

Ovarian cancer is hard to spot in its early stages which makes it one of the most deadly.

According to scientists at the Pacific Northwest Research Institute in Seattle, US, the new diagnostic method is at least as effective as the currently used test.

"Many cancers have a high cure rate if diagnosed early," said lead researcher Dr Ingegerd Hellstrom.

"But not if diagnosed late. Unfortunately, ovarian carcinoma is most often diagnosed when it is already in an advanced stage.

"Even after surgery and chemotherapy, relapses are common."

Concerns

The current test for ovarian cancer (CA125) is useful in diagnosing late stage cancers. But it is not very good at identifying early stage disease and sometimes gives "false positive" results.

The new marker (HE4) appears to be more sensitive but researchers cannot be sure until it is tested more thoroughly.

"It certainly may be a useful cancer marker but I would question its specificity for ovarian cancer as it is produced in other cancers such as breast cancer and lung cancer," said Dr Colin Dingle, a rival researcher at the University of Sheffield in northern England.

Dr Grant Sellar of Cancer Research UK's oncology unit in Edinburgh said there was great interest in finding an early detection method for ovarian cancer. But he said it would have to be tested in clinical trials.

"Early detection of cancer is always a desirable feature and being able to do that simply with a blood test is potentially very important," he told BBC News Online.

"But it has to be specific and sensitive so it doesn't give false positives."

The research is published in the journal Cancer Research.