演題番号 : P43-6
INTRODUCTIONS AND OBJECTIVES:
Abiraterone acetate(AA) is an orally administered irreversible inhibitor of CYP17 gene products, resulting in reduced intratumoral and adrenal-related synthesis of androgens. Although abiraterone acetate combined with prednisone has been shown to improve outcomes in patients with castration resistant prostate cancer (CRPC), only less than 65% of the treated population could achieve the PSA response. Thus, it would be necessary to identify the biomarkers which could predict the susceptibility to this agent. Here, we investigated the relationship between pretreatment DHEA-S concentration and the response to AA treatment in Japanese patients with CRPC.
This study included a total of 33 consecutive patients with CRPC treated with AA plus prednisolone at Kobe University hospital after the approval of AA in Japan in July 2014. Univariate and multivariate analyses using logistic regression model was carried out in these 33 patients to determine the predictive factors for the susceptibility to this agent.
The values of serum DHEA-S at baseline were found to be significantly intercorrelate with the PSA response in correlation analyses (correlation coefficient; -0.46). As a result of ROC analysis, the optimal cut-off value of serum DHEA-S at baseline has been detected 47ug/dl in predicting ≧30% PSA decline with the treatment of AA. The cause-specific survival in the patients with serum DHEA-S over 47ug/ml were significantly longer than another. Multivariate regression analysis demonstrated that PSA value at baseline and serum DHEA-S concentration at baseline were detected as the independent factors to predict the time to treatment failure of AA.
Our data suggested that serum DHEA-S at baseline are associated with an efficacy of abiraterone acetate. Therefore, pretreatment DHEA-S could be a predictive biomarker of abiraterone acetate in the patients with CRPC.