Clinical implications of using molecular diagnostics for ovarian cancers

In the era of morphologic diagnostics, any epithelial tumor on or involving the ovaries was presumed to come from and be strictly of ovarian origin, apart from the rare but clearly metastatic tumors. Thus, many women who might have had small fallopian tube primary cancers that rapidly extended on to or into the ovary were deemed to have ovarian cancer. Now, as we begin to better understand that there are different types of cancers of nonuterine Muellerian origin, we expand upon the morphologic to add the molecular characteristics. Morphomolecular characteristics are being applied to drive clinical advances including development and optimization of predictive and prognostic biomarkers, redefinition of historical controls, and consideration of novel clinical trial designs. Ovarian cancer, not a common cancer to start with, is now subdivided into types, making ever smaller clinical cohorts. The first studies evaluating tubo-ovarian Muellerian cancers of morphomolecular types have begun. Deleterious mutations in BRCA1 or 2 have been validated as the first new predictive and prognostic biomarker of the high-grade serous ovarian cancer type and polyADPribose polymerase inhibitors, the first targeted agents for this morphomolecular entity. Similar progress is developing in other tubo-ovarian cancer types. This new knowledge is driving the building of a structure-function-type relationship that is generating novel clinically applicable hypotheses for testing.