**15. In summary**

There are numerous types of genetic mutations causing sporadic and hereditary ovarian cancers and more to be discovered yet. These mutations cause genomic instability in turn leading to cancer causation. Having a certain type of mutation will gives rise to clinically specific type of ovarian cancer, with different response to treatment, prognosis and predictability in behaviour.

Early identification of these mutations, genetic counselling will optimise the patient outcome, prevention of the ovarian and other genetically predisposed cancers in next generations.

Developing a universal testing pathway which is cost effective, is still challenging due to various factors.

The arrival of personalising treatment with Molecular typing of Ovarian Cancer has revolutionised maintenance therapy in Ovarian Cancer that has never seen before. Not only we are routinely screening for germline and somatic BRCA mutation upfront in all newly diagnosed Ovarian Cancer, we increasingly modify our treatment paradigm by providing PARPi in DNA mismatch repair deficiency detected patients. This extends from just BRCA mutation to the other Homologous recombinant deficiency genes as delineated in **Figure 1**. In 2020, FDA approved of MEK-inhibitor, Trametinib for Low grade Ovarian Cancer. And soon to be NICE guidelines for routine screening for Microsatellite instability genes, MMR MSI in all Endometrial Cancer, in search for 40% incidence of MSI MMR deficiency.

In 2021 November, with the sentinel FDA approval for liquid biopsy testing in solid cancers, which was predominantly based on detection of BRCA genes and most HRD genes, this has solid foundation in one test for defective molecular markers in blood, hopefully well before development of Cancer, for our exciting future to come.
