Surgical outcome score (SOS), a new algorithm based on HE4 and CA125, to predict surgical outcome in primary epithelial ovarian cancer (EOC) patients (pts).

Abstract

5549 Background: There are no clinical or biomolecular algorithms to predict surgical outcome in EOC pts. Recently, we showed that the combination of HE4 and CA125 predict surgical outcome in advanced primary EOC (ASCO 2012). We validated the cut-off values in an independent cohort and developed a new algorithm to predict surgical outcome-SOS. Methods: Pts with primary EOC (n = 193) were selected for a retrospective study between 2003 and 2011. Preoperative serum HE4 and CA125 levels were measured. The predictive values of HE4 and CA125 were analyzed using the receiver operator characteristic (ROC) with the corresponding area under the curve (AUC). Separate logistic regression algorithms for pre- and postmenopausal women were utilized to categorize pts into low and high-risk for residual disease, using CA125 and HE4 within SOS algorithm. Furthermore we performed a multivariate analysis for prediction of progression free- (PFS) and overall survival (OS). Results: Maximal cytoreduction was achieved in 67.4% pts. Serum HE4 expression correlated with residual disease (p<0.001, RR: 2.74, 95%CI 1.65-4.54), reaching a 76.2% sensitivity (Se), 56.9% specificity (Sp) and 83.1% negative predictive value (NPV), with 235 pM cut-off value. CA125 correlated with residual disease in premenopausal pts (p=0.031, RR: 3.13, 95%CI 1.28-7.65). For a CA125 cut-off of 500 IU/l, the Se, Sp and NPV were 39.7%, 69.8%, and 70.3%, respectively. ROMA predicted surgical outcome (AUC = 0.70, p <0.001, 95% CI = 0.624-0.776, RR = 2.54), reaching a 76.2% Se, 53.5% Sp for 81% cut-off value. SOS algorithm performed better than HE4 or CA125 alone, and ROMA (AUC= 0.741, p < 0.001, 95% CI 0.670-0.812, RR = 4.98). The Se, Sp and NPV was 90.5%, 46.5% and 90.9%, respectively, for a SOS cut off value of 21.5%. FIGO stage and residual disease were the only prognostic factors for both PFS and OS. SOS was an independent prognostic for PFS (p = 0.009, HR = 1.014, 95% CI = 1.004-1.025), but not for OS. Conclusions: This independent validation study confirm the predictive value of CA124 and HE4 on surgical outcome. The combination of HE4 and CA125 within the SOS score improve the prediction of surgical outcome, and therefore of PFS.