New study - odd finding?
"... a velocity of PSA decline >11 ng/mL per month (HR 2.124 ...), and a time to PSA nadir ≤9 months (HR 0.276 ...) were significantly associated with an increased risk of progression to CRPC."
(They also found mets & a high nadir to be risk factors.)
Why would a faster fall of PSA to nadir, which most would consider a good response to ADT, accelerate CRPC?
Medicine (Baltimore). 2017 Sep;96(36):e7823. doi: 10.1097/MD.0000000000007823.
Rapidly decreasing level of prostate-specific antigen during initial androgen deprivation therapy is a risk factor for early progression to castration-resistant prostate cancer: A retrospective study.
Ji G1, Song G, Huang C, He S, Zhou L.
Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center of China, Beijing, China.
To build a practical model for predicting the progression to castration-resistant prostate cancer (CRPC) after androgen deprivation therapy (ADT).In all, 185 patients with prostate cancer who had received ADT as the primary therapy at our institution, from 2003 to 2014, were retrospectively enrolled. The following clinical variables were included in the analysis: age, clinical tumor, node, metastasis stage, Gleason score, risk groups of prostate cancer, prostate-specific antigen (PSA) at the initiation of ADT, PSA nadir after ADT, velocity of PSA decline, and the time to PSA nadir. Cox proportional-hazards regression models were calculated to estimate effects of these variables on the time of progression to CRPC.On univariate and multivariate analyses, the presence of distant metastasis before ADT (hazard ratio [HR] 6.030, 95% confidence interval (CI) 3.229-11.263, P = .001), higher PSA nadir (HR 1.185, 95% CI 1.080-1.301, P = .001), a velocity of PSA decline >11 ng/mL per month (HR 2.124, 95% CI 1.195-3.750, P = .001), and a time to PSA nadir ≤9 months (HR 0.276, 95% CI 0.162-0.469, P = .004) were significantly associated with an increased risk of progression to CRPC.Patients with a rapidly decreasing PSA level in the initial phase of ADT are more likely to progress to CRPC. Our findings provide a practical approach to screen patients during ADT for early identification of those likely to progress to CRPC, allowing treatment to be modified to improve outcomes.
PMID: 28885333 DOI: 10.1097/MD.0000000000007823