Epigenetic markers point towards ovarian cancer diagnostic

Ovarian cancer is relatively rare, but because it’s often detected at a late stage, it is the leading cause of death due to gynaecological cancers, and the sixth leading cause of cancer death in women.

Now a discovery by researchers at Sydney’s Garvan Institute might help in the fight against ovarian cancer by enabling early detection.

The researchers used whole genome profiling to identify six genes that undergo DNA methylation in a majority of ovarian cancers.

This discovery could lead to a new diagnostic test that looks for these epigenetic traces of ovarian cancer.

Early diagnosis can mean the difference between life and death. Ovarian cancers are usually diagnosed only once the disease has spread past the pelvis and into other organs including the stomach, bowel and lungs. They are typically very hard to get rid of with surgery and they tend to become rapidly resistant to chemotherapeutics.

Women diagnosed at a late stage have a 30 per cent five-year survival rate. Women diagnosed at an early stage have a 90 per cent five-year survival rate.

“This was one of first studies that used whole genome techniques to directly profile DNA methylation aberrations in ovarian cancer – with the aim of identifying diagnostic biomarkers,” said Brian Gloss, who focused on the project for his PhD.

“One of the key methylated genes we identified was a novel gene, which had not been identified as being misregulated in any cancer before.

“When we then analysed a further 100 tumours, we found that the novel biomarker gene was methylated in 80 per cent of them.

“This paper represents the first half of our work. The next step will be to see how our panel of biomarker genes is methylated in a larger cohort of ovarian tumours, and to identify the function of our novel gene.

“The most difficult aspect of ovarian cancer is that it is a molecularly heterogeneous disease, meaning that each tumour can be quite different from the next.

“We need to show, therefore, that our panel of biomarkers will be a sufficiently rigorous diagnostic tool, able to catch the requisite number of tumours.”

The research was conducted by Brian Gloss, Dr Philippa O’Brien and Professor Susan Clark, and is published in the journal Cancer Letters.