Ex vivo organotypic tumor slice cultures (OTSC) have unique characteristics in terms of tissue processing time and the maintenance of original microenvironment. Moreover, drug screening has been successfully performed on OTSC in a clinically meaningful time window.

For these reasons, we designed a study to assess the feasibility of establishing OTSC in OC patients and the concordance between ex vivo sensitivity and in vivo treatment response. If proven effective and reliable, OTSC could be introduced into clinical practice as empirical predictor of patients' response to platinum.

Most patients with ovarian cancer (OC) present with advanced stage and severe symptoms. The standard of care is based on an association between surgery and platinum-based chemotherapy, to which targeted therapies have been added since 2014. Despite significantly improved outcomes, there are still 15-20% of patients resistant to platinum-based chemotherapy without many therapeutic options and poor prognosis. It is urgent to select this population thus limiting useless undesirable effects and exploring more effective therapeutic options before clinical conditions worsen. To date, there are no validated predictive markers of primary platinum refractory or resistant disease and traditional cancer models are currently incompatible with treatment time window in this clinical setting.

Among cancer models, ex vivo organotypic tumor slice cultures (OTSC) have unique characteristics in terms of tissue processing time and the maintenance of original microenvironment. Moreover, drug screening has been successfully performed on OTSC in a clinically meaningful time window.

For these reasons, we designed a study to assess the feasibility of establishing OTSC in OC patients and the concordance between ex vivo sensitivity and in vivo treatment response. If proven effective and reliable, OTSC could be introduced into clinical practice as empirical predictor of patients' response to platinum.

Inclusion Criteria:

1. Preoperative clinical, serological and radiologic suspicion of International Federation of Gynecology and Obstetrics (FIGO) stage IIIC or greater ovarian, fallopian tube, or primary peritoneal cancer;
2. Age over 18 years;
3. Estimated life expectancy of at least 4 weeks;
4. Fagotti score (PIV) > 8 or patients not considered operable in the first place for any reasons;
5. Histologic diagnoses of epithelial ovarian cancer at frozen section.

Exclusion Criteria:

1. Non- epithelial histology at frozen section;
2. Patients enrolled in other clinical trials.