The debate over early detection testing for ovarian cancer is a complex and nuanced one, with potential benefits and harms that need careful consideration. While the ads for this new blood test in Australia urge women to be proactive, the reality is that the test is not a silver bullet and may do more harm than good if not used appropriately.
One of the key issues is the accuracy of the test. With a sensitivity of 78.2%, it may miss ovarian cancer in about one in every five people with the disease. This is a significant error rate, especially for a rare disease like ovarian cancer. As Dr Barry Kramer points out, 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. This could lead to unnecessary anxiety, further testing, and psychological distress, as well as additional medical costs.
The test is also not a general population screening test and should not be used as a standalone diagnostic tool. It is designed for people with a higher risk of ovarian cancer, such as those with a family history, genetic risk factors, or other factors flagged by their doctors. However, the company running the test, BCAL Diagnostics, doesn't provide much information on how to identify these high-risk individuals, leaving room for enthusiastic physicians or fearful patients to make the selection process difficult.
The lack of robust evidence supporting the effectiveness of blood-based early detection screening tests is another concern. As Dr Brooke Nickel from the University of Sydney’s school of public health points out, there is no evidence demonstrating that these tests improve health outcomes, including in higher-risk groups. Terms like 'silent killer' and 'proactive' can distort the public understanding of risk and blur the trade-offs between early detection and potential harms.
The urgency of finding a solution for ovarian cancer is undeniable, with a survival rate of just 49%. However, as Anita Dessaix, the chair of the Cancer Council’s public health committee, emphasizes, any test used for cancer screening must be 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. If a symptom is unusual or persists, they should seek medical advice without delay.
In conclusion, while the idea of early detection for ovarian cancer is appealing, the reality is more complex. The test is not a perfect solution and may do more harm than good if not used appropriately. The key is to strike a balance between early detection and potential harms, and to ensure that any testing is supported by strong evidence and used in a targeted and responsible manner.
