Pathological chemotherapy response score predicts survival in patients with advanced ovarian cancer receiving neoadjuvant chemotherapy: systematic review and meta analysis of …

Background: The chemotherapy response score (CRS) has been recommended for reporting histological tumour response to neoadjuvant chemotherapy (NACT) in tubo-ovarian high-grade serous carcinoma (HGSC). The CRS reproducibly stratifies patients into complete/near-complete (CRS3), partial (CRS2), and no/minimal (CRS1) response. Studies have shown an association between CRS and progression-free survival (PFS) but not overall survival (OS).Methods: We undertook a systematic review and meta-analysis and established an international collaboration to pool individual patient data (IPD) from 16 sites in 11 countries. All patients had stage IIIC/IV HGSC, received 3-4 NACT cycles and a minimum 6-month follow-up. Random effects models were used to derive combined odds ratios in the pooled population to investigate associations between CRS and PFS and OS.Findings: 5 studies were identified that included 490 patients: 4 were at low-risk of bias. Unpublished IPD for 875 patients were obtained. 907 patients were included. Median PFS was 15 months (IQR 6-66) and median OS was 28 months (IQR 7-90). The pooled hazard ratio (HR) for PFS (CRS3 compared to CRS1/CRS2) was 0· 52 (95% CI, 0· 43-0· 63; P< 0· 001). No heterogeneity was identified (Q= 5· 02, p< 0· 832, I2= 0· 0%). The pooled HR for OS (CRS3 compared to CRS1/CRS2) was 0· 67 (95% CI 0· 52-0· 86, P= 0· 001; Figure 2b). No heterogeneity was identified (Q= 8· 48, p< 0· 487, I2= 0· 0%).Interpretation: CRS3 was significantly associated with improved PFS and OS compared to CRS1/2. This robust, reproducible biomarker can be incorporated into therapeutic …