Ovarian cancer may be detected by Down Syndrome blood test

9 Sep 2016

St John of God Subiaco Hospital Head of Gynaecological Cancer Research, Dr Paul Cohen, in collaboration with researchers from The Translational Obstetrics Group at the Mercy Hospital for Women in Melbourne and the Victorian Clinical Genetics Service, have discovered ovarian cancer DNA in the blood at early stages of the diseases, making early blood screening for the disease a possibility.

Dr Cohen said while more research was needed, the detection and monitoring of specific cancer mutations in the blood holds much promise for early screening of the disease.

The earlier ovarian cancer can be detected, the earlier treatment can begin and ability to stop the cancer spreading to surrounding tissues and organs.

“Ovarian cancer remains the leading cause of gynaecologic cancer-related deaths in developed countries and there is a pressing need for an effective screening test,” Dr Cohen said.

“Currently it is very difficult to detect ovarian cancer and symptoms can be vague and similar to other conditions.

“The blood test CA125 – a protein found in the blood produced by ovarian cancer cells – can be used to help diagnose or exclude ovarian cancer. However, there are other causes for raised CA125 levels, such as menstruation, endometriosis or ovarian cysts.

“A pelvic ultrasound scan and the CA125 level are used to determine if an ovarian mass may be cancerous and if surgery is required, but are not always accurate.”

High grade serous ovarian cancer accounts for most deaths from the disease and demonstrates marked chromosomal instability. This characteristic feature led the research team to propose that DNA from malignant ovarian tumours could be detectable in the blood of patients.

Dr Cohen said the non-invasive prenatal blood test (NIPT) can detect circulating DNA from the tumour in the blood stream.

“The test only detected 40% of ovarian cancers in blood samples taken from a cohort of Western Australian women before undergoing surgery for the disease,” he said.

“However, NIPT detected an equivalent number of early stage cancers which is a novel finding. The testing platform requires further refinement if circulating DNA is to have potential in screening for ovarian cancer.

“However, the NIPT test was negative in 94% of patients (benign controls) who did not have ovarian cancer and so, in conjunction with pelvic ultrasound and CA125 levels, it may help to distinguish malignant and benign ovarian tumours prior to surgery.”

Dr Cohen said it is possible that the blood tests for circulating DNA could be translated to detecting other forms of cancer in the future. Circulating tumour DNA is already being used to monitor patients’ responses to chemotherapy.

To help raise funds for further ovarian cancer research, a cocktail event is being held on 19 October. Get your ticket here.

“The results of the study showed that it is possible to detect early stage ovarian cancer in the absence of patient-specific tumour DNA using a blood test.”

The St John of God Subiaco Hospital Gynaecological Cancer Research Group is currently conducting further studies on ovarian cancer screening with its Victorian collaborators, including Dr Lisa Hui, Dr Mark Pertile and Professor Stephen Tong.

Ovarian cancer is the eighth most common cancer and the sixth most common cause of cancer death affecting women in Australia.

The Norman Beischer Medical Research Foundation funded the study.

The research results were recently published in BMC Magazine.