ABSTRACT
Objective:To investigate the clinical characters and prognostic value of PSA flare and bone flare in metastatic castration resistant prostate cancer(mCRPC) patients received Abiterone acetate(AA) therapy.Methods:A retrospective study was conducted for 93 mCRPC patients treated with AA from Jul.2016 to Dec.2020. Mean age was (75.4±8.9)years, median PSA was 58.2 (16.4, 148.6)ng/ml. Patients received at least 6 months of AA treatment. PSA flare was defined as an increase of PSA after AA therapy followed by a decrease. Bone flare was defined as disease progression after 3 months of therapy, typically based on increased lesion intensity or number, and reevaluation 6-9 months later showed improvement in the scan. The clinical characters and prognostic value of the flare phenomenon was evaluated and analyzed respectively.Results:The median follow up time was 16 months(6, 54 months), fourteen patients showed PSA flare at first month after AA treatment, and median time of duration was 2 months(1, 7 months). The serum alkaline phosphatase (ALP) had a similar rising trend along with PSA flare[115.5(98.0, 198.5)U/L vs. 119.0(97.0, 288.8)U/L, P=0.016]. Seven patients showed bone flare and 3 cases co-existed with PSA flare. Multivariate Cox regression analysis indicated bone flare was an independent protective factor for progression free survival(PFS)( HR=0.117, 95% CI 0.015-0.895, P=0.039), PSA flare had no significant influence on PFS ( HR=1.314, 95% CI 0.554-3.121, P=0.536)and overall survival(OS)( HR=1.348, 95% CI 0.393-4.263, P=0.635). Log-rank test showed patients with bone flare had a longer PFS( P=0.016) and OS( P=0.047) compared with patients without bone flare. Conclusions:PSA flare always faded away after 2 months AA therapy and had no influence on PFS and OS. Bone flare maybe an indication for better prognosis.