The chemotherapy response score is a useful histological predictor of prognosis in high‐grade serous carcinoma

Abstract

High-grade serous carcinoma (HGSC) is the most common tubal/ovarian malignant tumour, and usually presents at an advanced stage. Interval debulking surgery (IDS) after neoadjuvant chemotherapy (NACT) is being increasingly used for the management of these patients. The chemotherapy response score (CRS) has been proposed for grading the response of tubo-ovarian HGSC to NACT on the basis of examination of IDS specimens. Our aims were to evaluate the CRS in post-NACT cases, assess the interobserver agreement, and correlate it with overall and progression-free survival. The CRS was applied by two independent pathologists on omental and adnexal tumour tissue sections from post-NACT patients with HGSC who had undergone IDS. The assigned primary site of tumour origin was documented. The interobserver agreement and prognostic significance of the CRS were evaluated. There were 103 cases, and in 61.1% of cases a fallopian tubal origin was confirmed. There were 26, 35 and 42 cases with CRSs of 1, 2, and 3, respectively. The interobserver variability for CRS was low (κ = 0.806). The CRS showed a significant correlation with progression-free survival (CRS 1 and 2 versus 3: median survival 16 months versus 18 months; P = 0.004); however, after controlling for debulking status, this association was not significant. The CRS applied to adnexal sections did not show any prognostic significance for either progression-free or overall survival. The CRS is an easy and reproducible method for predicting the prognosis in post-NACT HGSC patients.