A new study out of the UK suggests that greater awareness is needed for the use of CA-125 as a biomarker in the diagnosis of ovarian cancer.

New study supports the case for CA-125 biomarker test in ovarian cancer diagnosis

Research into improving outcomes for ovarian cancer patients is ongoing but a new study out of the UK suggests that greater awareness is needed for the use of CA-125 as a biomarker in the diagnosis of the disease.

CA-125 is a protein that is found in greater concentration in tumor cells, particularly ovarian cancer cells, than in other cells of the body.

Every year approximately 1600 women are diagnosed with ovarian cancer in Australia. The 5 year survival rate is just 44% – that’s because there are often no obvious symptoms and so the cancer is only diagnosed once it has spread.

The study, published by the Oxford University Press, supports evidence that elevated CA-125 levels (more than 35 U/mL) have high specificity for detecting ovarian cancer in women who present to a GP with abdominal bloating, pelvic pain or urinary symptoms.

Researchers reviewed more than 2900 CA-125 tests ordered by GPs over one year and found that 8% were elevated and, of these, 11% of women had ovarian or peritoneal cancer. A further 11% had other serious pathology.

They suggest that these findings show that CA-125 is a useful diagnostic test, if it is followed up early and any changes are monitored over time.

The researchers did not, however, recommend that the CA-125 biomarker be used as a screening test for low-risk women with no symptoms due to the test’s poor sensitivity and the potential for over-investigation and subsequent distress for patients who do not have ovarian cancer.

Melbourne GP Professor Jon Emery, professor of primary care cancer research at the University of Melbourne, spoke to Australian Doctor and said the findings added to the existing evidence that CA-125 might be a useful biomarker but that Australian GPs had been slow to implement recommendations on its use.

The National Cancer Expert Reference Group released ovarian cancer Optimal Care Pathways in June 2016 to improve care for ovarian cancer patients in Australia. The group recommends CA-125 testing for women presenting to their GP with potential symptoms, alongside routine blood tests, pelvic ultrasound and CT scan if appropriate, but local awareness is poor.

“Many GPs are not yet aware of the Optimal Care Pathway, but there are various initiatives across the states beginning to raise awareness of them and implement them in general practice,” Professor Emery said.