Cohen PA, et al. - Researchers reviewed current evidence to determine the prognostic value of chemotherapy response score (CRS) for women with tubo-ovarian high-grade serous carcinoma (HGSC) treated with neoadjuvant chemotherapy (NACT). Establishing an international collaboration, they perfrmed a systematic review and meta-analysis, pooling individual patient data from 16 sites in 11 countries. They included 877 patients with stage IIIC/IV HGSC, 3–4 NACT cycles and >6-months follow-up from published and unpublished studies. Patients with complete/near-complete response vs partial and no/minimal response showed significantly improved progression-free survival and overall survival. Validation of CRS in this real-world setting suggests its strong and reproducible value as a biomarker with potential to be included in therapeutic decision-making and clinical trial design.