Cancer: Sweet Test to Reduce False-positive Diagnoses

Photo: Klas Ola Blixt

Professor Ola Blixt testing for sugars in his Copenhagen lab; © University of Copenhagen

The world’s most widespread test for ovarian cancer reports false-positives in 94 of 100 diagnosed cases. Now, chemists at the University of Copenhagen working with clinical researchers at University College London have developed a method able to halve the number of false-positives.

When fully developed, the new test will spare a significant number of women from unnecessary worry and further testing. Furthermore, global health care providers stand to save substantial sums – just by including a test on a certain sugar molecule in tandem with the currently prevailing diagnostic test.

Ola Blixt is a chemical glycobiology professor at the Department of Chemistry, University of Copenhagen. He and Professor Usha Menon have led the research efforts of the teams at the Gynaecological Cancer Research Centre, University College London and the Copenhagen Center for Glycomics, who have succeeded in developing this new method that tests for ovarian cancer. The method helps distinguish between cancer and otherwise benign conditions and is called glycoprofiling.

Ola Blixt hopes that glycoprofiling will be incorporated in prevailing ovarian cancer diagnostics “kits” because there is simply so much distress that follows in the wake of a false diagnosis. “When a woman is informed that she might have cancer, she will always be terrified. She will also require further testing and this can be uncomfortable. Furthermore, there is the risk that she will encounter a considerable wait time before being provided with an accurate answer. I think that it is vital to clear those women who are misdiagnosed with cancer in a quick and safe manner. Our researches suggests that the new method, glycoprofiling, could improve differential diagnosis and significantly reduce the number of patients elected for further testing,” says Blixt.

Three-percent of all women will be tested for ovarian cancer in their lifetimes. In the United States alone, every year 100,000 women receive the distressing message that they might have cancer, following the initial test.

Women with ovarian cancer have an elevated amount of a protein known as CA125 in their blood. Therefore, current tests focus on this protein. Unfortunately, a wide range of other and far more benign conditions also increases CA125 figures. These include benign cysts, infections and even menstruation and pregnancy.

Ola Blixt directs the new diagnostic tests at an entirely different biological molecule, namely a sugar that coats the surface of the CA125 protein. Blixt explains that the presence of this specific sugar is limited to women who really are affected by ovarian cancer.

“All proteins have a type of sugar-coat – small, complicated sugar molecules that reside on a protein’s surface. When cancer is present in the body, we can observe a chemical change in this sugar-coat. It is a very complex phenomenon. Luckily, it is very simple to investigate and determine the presence of this transformed sugar coating,” states Blixt.; Source: University of Copenhagen