TOP2A as marker of response to pegylated lyposomal doxorubicin (PLD) in epithelial ovarian cancers.

Relapsed epithelial ovarian cancer (EOC) is frequently treated with pegylated liposomal doxorubicin (PLD). Unfortunately, most patients do not benefit from treatment. Prediction of response is crucial to optimize PLD use and avoid unnecessary toxicities. We aimed at assessing the value of topoisomerase II alpha (TOP2A) expression as predictive marker of response to PLD-based therapy in patients with relapsed EOCs. We retrospectively analyzed Formalin Fixed Paraffin Embedded (FFPE) tissues from 101 patients with platinum resistant (PR) or partially platinum-sensitive (PPS) EOCs treated with PLD-based chemotherapy beyond second line in three referral cancer centers between January 2010 and June 2018. TOP2A expression was measured by immunohistochemistry (IHC): images of each sample were acquired by optical microscope and analyzed by using automatic counter software. Correlation between TOP2A expression and response to PLD was assessed. Since no cut-off for positivity has been validated yet, we dichotomized TOP2A expression based on a cut-off of 18% (mean value in this study). TOP2A expression beyond cut-off was not prognostic for primary platinum-free interval in our series (p = 0.77) neither for optimal cytoreduction (p = 0.9). TOP2A > 18% was associated with a longer time to progression (TTP) following PLD-treatment, although not statistically significant (p = 0.394). No difference was observed between PR and PPS patients' groups (p = 0.445 and p = 0.185, respectively). Not unexpectedly, patients with TOP2A expression > 18% treated with PLD monotherapy achieved a longer TTP compared with PLD-doublet therapy (p = 0.05). Our data suggest that TOP2A status might predict activity of PLD in patients with PR/PPS EOCs.