[Can new molecular profiles in epithelial ovarian cancer modify therapeutics?]

Epithelial ovarian cancer (EOC) affects 4500 women a year in France, with a survival of 30% at 5 years. Treatment is based on extensive surgery and chemotherapy. Around 15% of EOCs are due to genetic mutation predisposition essentially with mutated BRCA1 and BRCA2 genes. Four histological subtypes are described (serous, endometrioid, and mucinous cells to clear), corresponding to different carcinogenesis and distinct molecular mutations. High-grade serous EOCs have a mutation of the BRCA genes in 20-30% of cases. This mutation causes a deficit of repair by homologous recombination of DNA in case of double strand break, allowing greater sensitivity to platinum salts and the use of PARP inhibitors, a protein involved in the repair of single-strand breaks of DNA. PARP inhibitors have shown efficacy in patients mutated BRCA but this effectiveness remains to be demonstrated in patients without congenital mutation, but with acquired BRCAness profile EOC. The BRCAness profile is defined by a tumor having a defect in DNA repair counterpart (not limited to BRCA mutation). Molecular definition of BRCAness is still not consensual but is necessary for the use of PARP inhibitors. Gene expression analyses have identified four subgroups of high-grade serous CEO: mesenchymal, proliferative, differentiated and immunoreactive. These four subtypes, not mutually exclusive, although correlated with prognosis, are not yet used in clinical routine.