Ads call ovarian cancer a ‘silent killer’. But does urging women to undergo early detection testing do more harm than good? | Antiviral

“Early detection blood testing” for ovarian cancer “is now available in Australia”, the online ads say, warning that “it’s not just women with a family history” who can be diagnosed.The ad calls the cancer a “silent killer” and says women who wish to be “proactive” can visit a website for early detection. It lists general symptoms including bloating, pelvic pain and the urge to urinate more frequently as potential signs of the disease.The website offers ovarian cancer testing for $1,495. People need a referral from a GP, and can either ask their own doctor or book a telehealth appointment through the website.Who should get an early detection test for ovarian cancer?While the ads seemingly target any woman who might be concerned by symptoms and who wants to be proactive, BCAL Diagnostics, which runs the early detection site, said the test was only designed for people with higher risk of ovarian cancer– those with a family history, genetic risk factors or other factors their doctors may have flagged.“It is not positioned as a general population screening test, a standalone diagnostic test, or a replacement for specialist clinical assessment or surveillance,” said BCAL’s chief executive, Anne-Louise Arnett.A blood test, it works by extracting fragments of DNA shed into the bloodstream, then scanning those for subtle chemical tags and genetic patterns that cancer cells produce early in their development. Machine learning is also used to detect the presence or absence of abnormal signals in the blood.It has not been approved by Australia’s drug regulator, the Therapeutic Goods Administration.How accurate is the test?The Ovarian Cancer Research Foundation said there was limited peer-reviewed data on the test, with a study published in 2025 including just 42 ovarian cancer samples.“Early findings are interesting, but more research is required before this test could be included in clinical guidelines or integrated into the Australian health system,” the foundation said.The manufacturer reports a sensitivity (how accurately the test detects actual cancer cases) of 78.2%. This means it may miss ovarian cancer in about one in every five people with the disease, according to the foundation. It reports a specificity (how accurately it returns a negative result in people without cancer) of 94%.Dr Barry Kramer, an oncologist who is a cancer-screening expert and a former director of cancer prevention at the US National Cancer Institute, said a 6% error rate for specificity was significant especially when it comes to rare diseases like ovarian cancer.Kramer said ovarian cancer was more common in older women. He said assuming it occurred in roughly 30 out of every 100,000 women over 50 each year: “If the test is given to 100,000 older women, it will accurately indicate cancer in about 23 of them.”“But in the 99,970 women without cancer, about 5,998 will test positive,” he said.“Those 5,998 women, having paid about $1,495 out-of-pocket, will now go on to further testing in the Australian healthcare system,” Kramer said, adding that this could create fear, psychological distress and further medical costs.While restricting testing to women at high risk could be beneficial, he said: “The company doesn’t provide much information about how to do that, and enthusiastic physicians or fearful patients might make the selection process difficult.”Of cases in which cancer is detected correctly, Dr Brooke Nickel from the University of Sydney’s school of public health, said there was “no robust evidence which demonstrates blood-based early detection screening tests improve health outcomes, including in higher-risk groups”.Nickel said terms like “silent killer” could “make rare diseases feel more common or immediate than they may be and pairing this with empowerment language can also suggest that more testing is always beneficial”.“In reality, screening decisions are complex and this kind of messaging can blur trade-offs and also distort the public understanding of risk,” she said.Weighing up early detection with potential harmsAnita Dessaix, the chair of the Cancer Council’s public health committee, said early detection of ovarian cancer was vital “but it’s important that any test used for cancer screening is supported by strong evidence demonstrating that the benefits outweigh the potential harms”. “People should not ignore symptoms and should discuss any concerns with their GP,” she said. “If a symptom is unusual for them or persists, they should seek medical advice without delay.”David Hunt, the research and policy director of the Ovarian Cancer Research Foundation, said with a survival rate of just 49%, people who are affected are desperate for a solution.“The [BCAL] test may have some value but doesn’t yet meet the threshold for sensitivity and specificity.” Melissa Davey is Guardian Australia’s medical editor Antiviral is a fortnightly column that interrogates the evidence behind the health headlines and factchecks popular wellness claims