Understanding ovarian cancer pathways a prerequisite to better therapies

A/Professor Therese Becker

By Linda Music

This month is Ovarian Cancer awareness month, so we caught up with Associate Professor Therese Becker who talked about the ovarian cancer research being conducted at the Centre for CTC Diagnostics & Research (CCDR).

A/Professor and CONCERT Biobank manager, Dr Joseph Po, are looking at isolating circulating ovarian cancer cells to identify biomarkers for therapy response and resistance.

Ovarian cancer has one of the poorest cancer outcomes and is the sixth most common cause of female cancer death. The poor outcome is, in part, due to the fact that it tends to be diagnosed late when the cancer is already at an advanced stage. However, poor outcomes are also because therapy development has been slow for decades.

Therese explains that most patients have their tumours surgically removed followed by chemotherapy. Despite many patients responding well initially, for many women the disease will reappear and fail subsequent chemotherapies.

“Better understanding of the molecular pathways that allow ovarian cancer to escape therapy are urgently needed,” said Therese.

“But this requires repeated sampling of some part of the tumour during changes in the cancer. Repeat sampling of actual tumour tissue however is risky for the patient.”

CCDR at the Ingham Institute has developed methods to use “liquid biopsies”, simple blood samples, to obtain parts of the tumour and repeatedly isolate circulating tumour DNA (ctDNA) and circulating tumour cells (CTCs) to further analyse for biomarkers of therapy response and resistance.

Therese explains that cancer cells can alter their appearance (phenotype) to escape chemotherapy drug effects. In particular, cells can change from a tightly tissue-bound state to a loosely-attached tissue state which allows the cells to leave the tumour mass and spread to other sites. While mostly spreading in the abdomen (peritoneum), ovarian cancer cells are also known to undergo such changes.

A/Prof Therese Becker and Dr Joseph Po, have recently developed improved methods to isolate CTCs from advanced ovarian cancer patients which accounts for cells that have undergone such phenotype changes.

Dr Joseph Po

“The method allows us to isolate about three times more CTCs, with a variety of phenotypes, from advanced ovarian cancer patients.

“The method may enable the clinical utility of CTCs to better monitor ovarian cancer in patients non-invasively and allows analysis of molecular pathways integral to therapy failure. Understanding these pathways will be a prerequisite to develop better next line therapies,” Therese explains.

To read about the signs and symptoms of Ovarian Cancer, visit: https://www.ovariancancer.net.au/page/134/signs-and-symptoms