Background: To address the unmet need for non-invasive tests to predict outcomes in OC we investigated the effect of the serum test, VeriStrat (VS), in independent cohorts of OC patients (pts) who were treated with platinum based chemotherapy following surgery. VS assigns “Good” (VSG) and “Poor” (VSP) classifications and has been shown to be prognostic in various tumor types and predictive for certain treatments. Methods: Samples from primary OC pts from the University Hospital, Essen (ESSEN), N= 108, and from OVCAD consortium (Berlin, Leuven, Hamburg, Vienna), N = 138, were obtained within 1 week before surgery that was followed by platinum-based CT. VS testing was done blinded to clinical data. Overall survival (OS) was analyzed by Kaplan-Meier method and compared using log-rank p-values. Cox models were used in multivariate analysis. Associations with categorical variables were analyzed by Fisher’s exact test. Results: The cohorts had similar distribution of VSG/VSP classification: 73% VSG (ESSEN), 71% VSG (OVCAD). The distribution by histology (non-serous/serous), and nodal status were different (p = 0.003 and p = 0.049). The results for OS in all pts (ALL), in pts with tumor (and/or metastases) present post-surgery (TPPS-pos), and in pts with complete resection and no metastases (TPPS-neg) are presented in the Table. VS was not associated with circulating tumor cells (ESSEN, p=0.736). In a Cox model analysis for TPPS-pos groups VS was independently significant (p= 0.016, ESSEN) or trended to significance (p=0.063, OVCAD). Conclusions: VS demonstrated similar results in two independent cohorts; in ALL and TPPS-pos populations it significantly correlated with OS in ESSEN, showed same trends in OVCAD, and was not correlated with OS in TTPS-neg pts. While requiring further investigation, VS may provide useful prognostic information.

* NR= not reached.