The CINSARC Genomic Signature as a Predictor of Resectability of High Grade Serous Ovarian Adenocarcinomas

The majority of primary cancers of the ovary or peritoneum are represented by high-grade serous adenocarcinomas. These are rare pathologies, the incidence of which is estimated at 7.1 per 100,000, representing approximately 4,500 new cases per year in France (INCA 2017). In the absence of effective screening, nearly 85% of patients have an advanced disease at diagnosis (corresponding to the FIGO III or IVA stage, characterized by diffuse peritoneal involvement). Despite multidisciplinary care, the majority of patients (80%) will recur within a median of 18 to 24 months.

It is therefore necessary to develop new tools, in particular molecular, in order to allow :

• to better select patients accessible to full interval surgery
• to exclude patients who would not benefit from this surgery in terms of survival

In 2010, Chibon et al. identified, from a cohort of patients with soft tissue sarcoma (STM), a molecular signature (called CINSARC), based on the expression profile of 67 genes involved in mitotic control and chromosomal integrity. The team showed that this transcriptomic signature is an independent prognostic factor in different types of STM, but also a prognostic factor more discriminating than the histological grade (FNCLCC), historical and major prognostic factor of STM.

Being initially made from frozen material and on a DNA biochip (Affymetrix), this signature was unusable outside the field of fundamental research. This is why CINSARC has been gradually optimized, first by the RNA sequencing technique on frozen tissue fixed in formalin (FFPE), and recently on FFPE tissue by the NanoString® technique. This very sensitive and inexpensive technique requires only small amounts of total RNA, making it compatible with use on "routine" diagnostic samples, microbiopsy or surgical biopsy, opening the door to real clinical application. Several clinical studies using this latest CINSARC optimization (called NanoCind®) to determine the treatment of patients with STM will also begin soon.

As a result of this work, necessary in order to more precisely support the potential of CINSARC in this pathology, the investigators hope to be able to assess from the diagnosis the evolutionary potential of the patients, which could make it possible to evaluate therapeutic strategies adapted to the profiles of each subpopulation: the investigators can for example imagine in theory a therapeutic de-escalation for low-risk patients, or else, for very high-risk patients, an intensified strategy.