Evaluation of the prognostic significance of human kallikrein 8 protein expression levels in advanced ovarian cancer by using automated quantitative protein analysis

5581 Background: Kallikreins, a subgroup of the serine protease enzyme family, are considered important prognostic biomarkers in cancer. Here, we sought to determine the prognostic value of kallikrein 8 (hkl8) in ovarian cancer using a novel method of compartmentalized in situ protein analysis. Materials and Methods: A tissue array composed of 150 advanced stage ovarian cancers, uniformly treated with surgical debulking followed by platinum-paclitaxel combination chemotherapy, was constructed. For evaluation of kallikrein 8 protein expression, we used an immunofluorescence-based method of automated in situ quantitative measurement of protein analysis (AQUA). Results: Mean follow-up time of the cohort was 34.35 months. One hundred twenty six of 150 cases had sufficient tissue for AQUA analysis. There was association between tumor mask hk8 protein expression levels and clinicopathological variables including grade (p=0.0011), residual disease (p=0.0063),clinical response to chemotherapy (p=0.0346). In univariate survival analysis there was a correlation between hk8 tumor mask expression and 5 years progression-free survival. Low hk8 expression correlated with better outcome (top vs. bottom quartile, p = 0.0319). In multivariate survival analysis, adjusting for well-characterized prognostic variables, tumor hkl8 expression level retained its prognostic significance for disease free survival (95%CI: 0.341–1.027, p=0.0468). Conclusions: Human Kallikrein 8 is an adverse prognostic factor in patients with ovarian cancer.The possibilities that hK8 may be suitable candidate as diagnostic, prognostic marker and therapeutic target merit further investigation. No significant financial relationships to disclose.