Why is early detection such a challenge? 

Tests such as mammograms for breast cancer, HPV screening and Pap smears for cervical cancer, and PSA blood tests for prostate cancer have saved millions of lives by catching disease early. For many cancers, finding the problem sooner dramatically improves survival. So why isn’t there an early detection or screening test for ovarian cancer yet—and how close are researchers to making one? 

Cancer is staged from 1 to 4, based on how much disease there is and whether it has spread. Early stage ovarian cancer (stage 1) means the cancer is confined to one area, so it’s usually easier to treat. Advanced disease (up to stage 4) has spread more widely and is much harder to manage. 

Early detection involves two components, early diagnosis and screening. 

Early diagnosis focuses on catching cancer at these earliest stages, often before symptoms appear.  

A screening test is a type of early detection test used routinely in people at average risk, even when they feel well. 

For ovarian cancer, there is currently no widely recommended screening test, nor a reliable early detection test for the general population.

Survival for ovarian cancer is strongly linked to stage and timing. Overall, about 49% of women in Australia survive five years after diagnosis. But when ovarian cancer is caught at an early stage, five-year survival rises to over 90%. Unfortunately, less than 20 per cent of women with ovarian cancer are picked up at stage one. 

More than 70 per cent of women with ovarian cancer are only diagnosed once the disease is advanced. At this stage, treatment options are limited, and the chance of recurrence (when the cancer comes back) is increased.  

Early detection could help doctors find ovarian cancer when it is most treatable, improving survival and reducing the likelihood of the disease returning.

Ovarian cancer isn’t one disease but a group of more than 30 different subtypes, each with its own biology, growth patterns, and genetic changes. A test that works for one subtype may miss another, so researchers must develop multiple detection strategies rather than a single one-size-fits-all test. 

The most common subtype, high-grade serous ovarian cancer (HGSOC), often starts in the fallopian tubes and spreads to the abdominal lining and other hard-to-reach areas. Symptoms such as bloating, abdominal discomfort, and changes in bowel or bladder habits are nonspecific and can be mistaken for less serious conditions, so ovarian cancer is often not suspected until it is more advanced. 

Current tools such as pelvic exams, ultrasounds, and the blood marker CA125 are not reliable for early detection. Small tumours are difficult to feel on exam or see on ultrasounds, and CA125 can be raised for many reasons unrelated to cancer or may not rise at all in some ovarian cancer cases.

Despite being the most lethal gynaecological cancer, ovarian cancer has received a very small share (less than one per cent between 2018-2023) of Australian government medical research funding. Limited funding slows progress and means fewer researchers can work on the problem. 

Large international studies have also shown how challenging early detection can be. For example, a major UK trial that combined CA125 blood tests with transvaginal ultrasound in over 200,000 women did not improve survival, even though it detected some cancers earlier—but not early enough. However, the study did yield valuable insights and a large bank of blood samples that are now being used by researchers worldwide to develop more sensitive tests. 

These “false starts” are part of the scientific process. Even when a test doesn’t deliver the hoped-for result, it helps researchers understand what doesn’t work and where to focus next.

Because ovarian cancer is so diverse, researchers expect that more than one type of early‑detection test may be needed to be effective. 

Australian scientists are among the global leaders in this field. The Ovarian Cancer Research Foundation (OCRF) is currently funding, or has previously supported, several promising projects, including: 

• OCRF7 (Prof Carlos Salomon / INOVIQ): A blood-based test that looks for tiny packages called exosomes and other signalling molecules released by high-grade serous ovarian cancer cells. This approach is expected to enter a feasibility trial in 2026. 
• Cleo Diagnostics (Dr Andrew Stephens): A blood test that measures different types of proteins associated with ovarian cancer, currently in clinical trials in Australia and the USA. 
• ProSeek Bio (A/Prof Michelle Hill) and Prof Michael Jennings: Tests that analyses protein sugars in the blood. The ProSeek Bio test is now being evaluated in clinical pathology laboratories. 
• Dr Kristina Warton: Tests that look at DNA patterns in the blood, currently at the validation stage. 
• A/Prof Jason Lee: Research into circular RNAs (similar to DNA) in the blood, still in early development. 

Internationally, there are around 18 active clinical trials testing early detection approaches for ovarian cancer, with several more tests in the validation phase. Examples include: 

• Avantect Ovarian Cancer Test (USA, UK, Australia): DNA-based blood test in clinical trials. 
• OVAwatch and OVA1®plus (USA): Blood-based biomarkers combined with imaging, in clinical trials. 
• Galleri® multicancer early-detection test (GRAIL, USA): A DNA-based test that can detect several cancers, including ovarian, with FDA Breakthrough Device designation*. 
• Mercy Halo / Evident Ovarian (USA): Exosome-based blood test with FDA Breakthrough Device designation*. 
• OVCAS1 (China): A test that looks for chemical changes in the blood, in clinical trials. 
• GlycoLocate™ (USA, UK): A test that detects specific patterns on blood proteins, in clinical trials. 
• OVAMethy and PROFOUNDOC studies (China): DNA-based blood tests in clinical trials. 
• ECHO Study (Mayo Clinic, USA): Another DNA-based blood test in clinical trials. 

*FDA Breakthrough Device designation means regulators are working closely with the developers to speed up evaluation for promising tests that address serious unmet needs.

In practical terms, most clinical trials of early detection tests will not proceed to real-world application - it may be more than five years before any reliable ovarian cancer detection test reaches clinics. Population-wide screening is likely to take even longer. But the number of active projects and the pace of discovery show that progress is accelerating. 

While researchers work toward early detection tools, the OCRF is also investing in new treatments. Even if early detection tests become available, effective therapies will still be essential—especially for women already living with advanced disease or at high risk. 

The goal is clear: to develop better ways to detect and prevent ovarian cancer, alongside more effective treatments, so that everyone affected can survive and thrive.