As yet, there is no reliable, sensitive and specific screening test for ovarian cancer. The current blood test measures CA-125, which is increased in both malignant and non malignant conditions and is mainly used to measure response to treatment, not to screen for early disease. It is also increased in gynecological and non gynecological conditions, so it is both non-specific and not sensitive. Therefore is it is not a useful tool for screening asymptomatic women for early ovarian cancer.

A new technique is being developed, which holds promise. Cancer cells have defects in small pieces of genetic information called microRNAs. These microRNA particles are released into the blood. The scientists trained a computer to detect miRNA neural patterns that are seen in the serum of ovarian cancer patients compared to when there is no ovarian cancer present.

Testing the blood for circulating microRNA is an avenue to detect ovarian cancer earlier than when it causes symptoms and is in an advanced stage. It is still unclear at which stage these miRNA find their way into circulation, and the technique still needs to be validated. At the present time, this has only been tested in the laboratory, but holds promise as an ovarian cancer screening technique in the future.

https://elifesciences.org/articles/28932