Olympia-MITO13-validation of a Laparoscopic Score to Predict the Chance of Optimal Cytoreduction in Advanced Ovarian Cancer Patients: an Open-label Prospective Multicentric-trial.

Results from large but retrospective studies clearly demonstrated that RT after primary surgery is the most important prognostic factor in AOC patients. Subsequently, several studies have shown a complete cytoreduction (RT=0) is associated with a statistically significant longer survival rate than minimal residual disease (RT=1-2 cm). As a consequence, a maximal surgical effort is considered the main goal to pursue in these patients.

However, data from the literature have shown that a certain percentage of AOC patients, variable between 10 and 80%, are still considered inoperable at time of primary surgery, and they are submitted to an unnecessary xipho-pubic laparotomy. This approach, beside affecting QoL, can be related to some complications and delay in starting chemotherapy. This result can be related to a series of variables, including patient's performance status, philosophy of the centre and skillness of the surgeon. Finally, the anatomic diffusion of the disease is described as one of the most limiting factor to an optimal cytoreduction.

In order to preoperatively identify patients with unresectable tumors, which can be spared an unnecessary exploratory laparotomy, several approaches have been attempted, including CA 125 serum levels and CT-scan. However, the accuracy of those parameters has been unsatisfactory, and limited by the retrospective nature of the studies and the highly variable rates of optimal cytoreduction in different series.

Laparoscopy is well-known to offer a direct and magnified vision of the peritoneal cavity and a better view of the upper abdomen. It allows the pathological assessment of the disease without an open surgical procedure, with a shorter operating time and better results in terms of post-operative morbidity. We first demonstrated in a pilot study that laparoscopy alone is able to provide the same information regarding the chance of optimal cytoreduction (RT<= 1cm) than standard laparotomy in clinically AOC patients. Since then, other investigators have confirmed the role of laparoscopy in the evaluation of the possibility of achieving optimal residual disease in the same clinical subset.

However, one of the major criticism to these studies was represented by the surgeon subjectivity in evaluating optimal debulking in relation to surgical team and operating room performances. Consequently, on the basis of previous published papers, we set up a quantitative predictive model, which provides each patient with a score, taking into account several laparoscopically-assessed sites of disease to objectively predict the chance of achieving optimal cytoreduction. This model gives each parameter (omental cake, diaphragmatic carcinosis, peritoneal carcinosis, superficial liver metastases, stomach infiltration, bowel infiltration and mesenteric retraction) a value of 2 (see "Statistical considerations").