Pathological Chemotherapy Response Score in Patients Affected by High Grade Serous Ovarian Carcinoma: The Prognostic Role of Omental and Ovarian Residual Disease.

The chemotherapy response score (CRS) has emerged as a simple and reproducible histopathological grading system for assessing chemotherapy response in patients affected by ovarian high-grade serous carcinoma. To evaluate the prognostic impact of histological tumor response in ovarian and omental surgical specimens from patients with advanced stage ovarian high-grade serous carcinoma. A cohort of 161 women were identified from the database of Department of Gynecology, "Fondazione Policlinico Universitario Agostino Gemelli IRCCS" of Rome, Italy between January 2014 and December 2017 with a follow-up of 65 months. All the omentum, the ovarian tissue and peritoneal samples, defined as "other sites," were reviewed by gynecological pathologists to assign a CRS of 1-3 to the omentum and ovarian sites and a score of 0-1 to the peritoneal tissue. The Cox proportional hazards regression and the log-rank test were used to assess the survival pattern and the prognostic value of the CRS adjusting for age and stage. The Kaplan-Meier method was applied to estimate the progression free and overall survival. The evaluation of adnexal disease showed significant differences in PFS, both in univariate and in multivariate analyses. On PFS univariate analysis, ovCRS1 vs. ovCRS3: HR, 2.27; 95% CI, 1.37-3.77; = 0.001; ovCRS2 vs. ovCRS3: HR, 1.83; 95% CI, 1.03-3.23; = 0.04, and on PFS multivariate model ovCRS1 vs. ovCRS3; HR, 2.53; 95% CI, 1.5-4.24; = 0.001 and ovCRS2 vs. ovCRS3; HR, 1.90; 95% CI, 1.08-3.37; = 0.03. Regarding the omental residual disease, as expected, CRS showed a significant prognostic value for OS and PFS; in detail the median PFS of patients with CRS1, 2 and 3 was 15, 15, and 22 months, respectively, the median OS was 41 and >50 months, respectively. Moreover, the univariate analysis for OS suggested that in our cohort the "other sites" score of 0 was significantly associated with an improvement in overall survival compared to score 1. We demonstrated for the first time the prognostic significance of adnexal CRS confirming also the prognostic role of omental CRS.