Nibrin is a marker of clinical outcome in patients with advanced serous ovarian cancer treated in the phase III OVA-301 trial

• High nibrin levels correlated with lower ORR and shorter PFS and OS in ROC patients
• High nibrin correlated with worse PFS and OS in a multivariate analysis
• Nibrin expression seems to be associated to the clinical outcome of ROC patients

ObjectiveThis study investigated the relationship between 13 proteins involved in DNA damage and the outcomes of patients with recurrent ovarian cancer (ROC).Patients and methodsImmunohistochemistry staining was performed in 114 diagnostic samples from patients with serous ROC who participated in the OVA-301 study, which compared pegylated liposomal doxorubicin (PLD) with a combination of trabectedin plus PLD. Percentage of positive cells for every marker was calculated and correlated with overall response rate (ORR), progression-free survival (PFS) and overall survival (OS).ResultsA statistically significant correlation between high levels of nibrin and lower ORR (P = 0.03), shorter PFS (P = 0.007) and shorter OS (P = 0.01) was observed. After stratification, in patients with platinum-sensitive disease treated with the combination of trabectedin plus PLD, high levels of nibrin correlated with lower ORR (P = 0.01) and shorter PFS (P = 0.02). A better clinical outcome (ORR, PFS and OS) was also associated to low levels of CHK2 in trabectedin plus PLD treated patients. No correlations were found in PLD-treated patients. According to the results of a multivariate analysis, there was a statistically significant correlation between high nibrin (P = 0.001) and low BRCA2 levels (P = 0.03) and a worse PFS, and between high nibrin levels and a worse OS (P = 0.006).ConclusionOur results indicate that high nibrin expression seems to be associated with a worse clinical outcome in serous ROC, particularly in patients treated with the combination trabectedin plus PLD. Prospective studies to determine clinical usefulness of nibrin as a possible biomarker in other series of patients with ROC are warranted.