Serum γ-glutamyltransferase as a prognostic biomarker in metastatic castration-resistant prostate cancer treated with enzalutamide

Abstract

Background/Aim: Serum γ-glutamyltransferase (GGT) is reportedly associated with survival and therapeutic response in various malignancies; however, as far as we are aware its impact on metastatic castration-resistant prostate cancer (mCRPC) has never been assessed. Patients and Methods: Fifty consecutive men with mCRPC receiving enzalutamide at a single cancer center were retrospectively evaluated. The primary endpoint was overall survival (OS) and the secondary endpoints were prostate-specific antigen (PSA) response, maximal PSA change, and PSA progression-free survival (PSA-PFS). Results: Multivariable analysis demonstrated that elevation of GGT (≥40 U/l) was significantly and independently associated with shorter OS (hazard ratio(HR)=3.61; p=0.004), as were lower hemoglobin (HR=6.04; p<0.001) and higher PSA (HR=4.38; p=0.009). Elevated GGT was also associated with poorer PSA response, maximal PSA change, and shorter PSA-PFS. Conclusion: Elevated GGT was an adverse prognostic indicator in men with mCRPC receiving enzalutamide. External validations would improve the generality of our findings.