Hundreds of Cochrane reviews have been published over the last 25 years relevant to the diagnosis and treatment of a wide range of cancers, including ovarian cancer. In a new review from July 2022, Clare Davenport, from the University of Birmingham in the UK, and colleagues examined the evidence on the use of multiple tests to detect it and she tells us what they found in this podcast.
Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. Hundreds of Cochrane reviews have been published over the last 25 years relevant to the diagnosis and treatment of a wide range of cancers, including ovarian cancer. In a new review from July 2022, Clare Davenport, from the University of Birmingham in the UK, and colleagues examined the evidence on the use of multiple tests to detect it and she tells us what they found in this podcast.
Clare: The symptoms of ovarian cancer are non‐specific, mimicking less serious conditions. This makes it difficult to diagnosis and many women with the disease die from it because it's already spread outside the ovaries when it is first diagnosed.
This makes it especially important that tests are accurate. If a woman's ovarian cancer is missed by a test, known as a false negative, this may result in the need for more extensive surgery when the diagnosis is made at a later date and may lower a woman's chance of survival. On the other hand, if a test makes a diagnosis of ovarian cancer when it is not present, a so-called false positive, this may result in anxiety and unnecessary further tests and surgery. Therefore, to try to avoid these errors, a combination of tests might be used and we looked into this by comparing the accuracy of four different test combinations, and found that there are important differences between them.
The four tests we looked at are the Risk of Malignancy Index (RMI) which combines ultrasound with a CA125 blood test; the Risk of Ovarian Malignancy Algorithm (ROMA) (which combines the CA125 and HE4 blood tests); the IOTA Logistic Regression model 2 (LR2) (which uses ultrasound) and the Assessment of Different NEoplasias in the adneXa model (ADNEX) (which combines the CA125 blood test and ultrasound).
We included 59 studies in the review, with a total of just over 32,000 women of whom about nine and a half thousand had a final diagnosis of ovarian cancer. One of our key findings was that the number of false positive and false negative test errors made by a test varied significantly based on whether women were pre- or post-menopausal. This makes it important to separate them in the results.
We found that RMI resulted in the highest number of missed ovarian cancer diagnoses out of the four tests studied in both pre- and postmenopausal women. For instance, in a group of 100 pre-menopausal women with ovarian cancer, RMI would miss 21 cancers, while ROMA would miss 18, LR2 would miss 11 and ADNEX would miss 6. In 100 post-menopausal women with ovarian cancer, RMI would miss 15 cancers, LR2 or ROMA would miss 9 and ADNEX would miss 7.
These findings suggests that ROMA, ADNEX or LR2 would miss considerably fewer cancers than RMI and, on this basis, they should be considered as replacements for RMI in both pre- and post-menopausal women. However, the choice of which of the three to use depends on the resources available in different healthcare systems. For example, ADNEX and LR2 require the skills of specialist sonographers whereas ROMA requires a blood test only.
Finally, in considering our findings, it's important to note that most of the studies we included were conducted in Europe in specialist hospital settings, and further research is needed to establish whether the accuracy of the tests is similar in women presenting in the community.
Mike: If you would like to learn more about the tests and the studies that evaluated them, and watch for an update to the review if that further research gets done, you can find the full version at Cochrane Library dot com with a simple search for 'tests for ovarian cancer'.