Nadir prostate-specific antigen best predicts the progression to androgen-independent prostate cancer

Development and validation of a novel risk model in newly diagnosed de novo bone metastatic prostate cancer (M1b): a retrospective study

Background

Previous studies suggested that bone metastasis has a significant effect on the time of progression to metastatic castration-resistant prostate cancer (CRPC) for newly diagnosed de novo bone metastatic hormone-sensitive prostate cancer (mHSPC). Nevertheless, the effect of different bone metastasis sites was not fully evaluated. This study aimed to develop and validate a novel bone metastatic risk model.

Methods

We enrolled 122 patients who were newly diagnosed with de novo bone metastatic prostate cancer following primary androgen deprivation based therapy at our institution from January 2008 to June 2021. The metastatic bone sites were classified into six sites: skull; cervical, thoracic, and lumbar vertebrae; chest (ribs and sternum); pelvis; upper limbs; and lower limbs. We calculated the bone metastatic score (BMS) for each site: 0 points were assigned for non-metastasis and 1 point was assigned for metastasis. The X-tile was adopted to acquire optimal cutoff points of BMS. We defined high-risk group (HRG) as BMS ≥ 3 and low-risk group (LRG) as BMS < 3. The new bone risk stratification was validated by calculating the area under the receiver operating characteristic curve (AUC). Subsequently, the relevant clinical prognostic variables were added to construct a predictive nomogram for predicting CRPC.

Results

The median patient age was 73 years. Most patients had Gleason score ≤8 (93 cases, 76.2%). The median follow-up duration was 11.5 months (range: 2-92 months). Eighty-six patients progressed to CRPC during the follow-up. The most common bone metastatic site was the pelvis (90.2%). The median BMS was 4. Seventy-six patients had HRG, while forty-six had LRG. The 1-, 2-, and 3-year AUCs for H/LRG were 0.620, 0.754, and 0.793, respectively. The HRG was associated with earlier time to CRPC. A nomogram based on four parameters (Gleason score, H/LRG, prostate-specific antigen [PSA] nadir, and time to PSA nadir) was developed to predict CRPC. Internal validation using bootstrapping demonstrated good accuracy for predicting the CRPC (C-index: 0.727). The calibration analysis demonstrated that the model performed well.

Conclusion

We established a novel H/LRG risk model for newly diagnosed de novo bone metastatic prostate cancer, which provided evidence to support clinical decision-making.

Nomogram Incorporating Contrast-Enhanced Ultrasonography Predicting Time to the Development of Castration-Resistant Prostate Cancer

Background

It is valuable to predict the time to the development of castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer (PCa). This study aimed to build and validate a nomogram incorporating the clinicopathologic characteristics and the parameters of contrast-enhanced ultrasonography (CEUS) to predict the time to CRPC after androgen deprivation therapy (ADT).

Methods

Patients with PCa were divided into the training (n = 183) and validation cohorts (n = 37) for nomogram construction and validation. The clinicopathologic characteristics and CEUS parameters were analyzed to determine the independent prognosis factors and serve as the basis of the nomogram to estimate the risk of 1-, 2-, and 3-year progress to CRPC.

Results

T stage, distant metastasis, Gleason score, area under the curve (AUC), prostate-specific antigen (PSA) nadir, and time to PSA nadir were the independent predictors of CRPC (all P < 0.05). Three nomograms were built to predict the time to CRPC. Owing to the inclusion of CEUS parameter, the discrimination of the established nomogram (C-index: 0.825 and 0.797 for training and validation datasets) was improved compared with the traditional prediction model (C-index: 0.825 and 0.797), and when it excluded posttreatment PSA, it still obtained an acceptable discrimination (C-index: 0.825 and 0.797).

Conclusions

The established nomogram including regular prognostic indicators and CEUS obtained an improved accuracy for the prediction of the time to CRPC. It was also applicable for early prediction of CRPC when it excluded posttreatment PSA, which might be helpful for individualized diagnosis and treatment.

Androgen deprivation therapy in patients with localized disease: Comparison with curative intent treatments and time to castration resistance. Results of the Spanish Prostate Cancer Registry

BACKGROUND

The effect of primary androgen deprivation therapy (ADT) in patients with localized prostate cancer (PCa) has not been well documented. The objective of the present study was to analyze the outcome of tumors treated with ADT as primary therapy in the Spanish Prostate Cancer Registry (19.4% of the series).

PATIENTS AND METHODS

Patients were classified in three groups: 1) with low/intermediate risk clinically localized tumors; 2) with high risk and locally advanced (T3-4) tumors; 3) with metastatic tumors. Time to castration resistance and overall cancer-specific survival were analyzed. In non-metastatic tumors, survivals in patients treated with ADT were compared with data from patients who underwent local treatments from the Spanish Prostate Cancer Registry.

RESULTS

703 cases were analyzed. There were significant differences in the time to castration resistance, which was lower in the group of metastatic tumors. During follow-up, there were 179 deaths (25.5%) of which 89 (12.6%) were due to PCa. After 3 years of ADT, only 14.6% of patients in group 1 had died (1% due to PCa), 20.5% in group 2 and 46.8% in group 3 (9.2% and 31.3% due to PCa, respectively). Cancer-specific survival was significantly worse in group 1 using ADT than radical prostatectomy or radiotherapy. In high-risk and locally advanced tumors, ADT also had a lower cancer-specific survival than local treatments.

CONCLUSION

A longer time until the castration resistance was observed in patients with well- and intermediate-risk localized tumors treated with ADT. Patients with metastatic tumors showed the shortest time to castration resistance.

Factors related to early castration resistance in metastatic prostate cancer. Results from the National Prostate Cancer Registry in Spain

INTRODUCTION

The objective of the study was to determine the factors independently related with the development of castration resistance (CR) in prostate cancer (PC) in the medium term.

MATERIAL AND METHODS

155 patients diagnosed with metastatic PC with a follow-up of up to 39 months. Data taken from the National PC Registry. The evaluated variables were age, PSA, nadir PSA, Gleason, perineural invasion, TNM stages, and ADT type (intermittent/continuous).

RESULTS

Mean follow-up 26,2±13,4 months. 47.1% developed early CR, with mean time until onset of 12,2±8,7 months. Univariate analysis the mean PSA was correlated with CR (290±905,1 ng/mL in non CR, 519,1±1437,2 ng/mL in CR, P<.001), mean age (73,3±8,3 years in non CR, 69,1±9,3 in CR P=.01), mean PSA nadir (15,5±57,3ng/mL in non CR, 15,9±23,7 ng/mL in CR, p<0,001), Gleason (in ≥8, HR:2,11. 95% CI: 1.22-3.65, p=0.006), and T stage (in T3-T4, HR: 2.85. 95% CI: 1.57-5.19, P<.001). Multivariate analysis the independent variables associated to CR are age (HR: 0.96. 95% CI: 0.94-0.99, P=.01), PSA nadir (HR: 1.65. 95% CI: 1,43-1,91, P<.001), and T3-T4 stage (HR: 2.11. 95% CI: 1.10-4.04, P=.02).

CONCLUSIONS

PSA nadir and T3-T4 tumor stage at diagnosis are associated to an increased risk of developing CR. In addition, age at diagnosis is shown as a variable that decreases risk. Therefore, an older age would be associated with lower risk probability of CR in the medium term.

Predictors of poor response to first-generation anti-androgens as criteria for alternate treatments for patients with non-metastatic castration-resistant prostate cancer

PURPOSE

There are no criteria for administering first- or second-generation anti-androgens (FGA and SGA, respectively) to patients with non-metastatic castration-resistant prostate cancer (nmCRPC). This study aimed to assess the efficacy of alternative FGA therapy in nmCRPC patients and the prognosis of these patients and to identify factors for predicting patients potentially responsive to FGA.

METHODS

Data from 63 men with nmCRPC who underwent alternative FGA therapy (bicalutamide, flutamide, or chlormadinone acetate) as first-line therapy after failure of primary androgen-deprivation therapy (PADT) between 2004 and 2017 at Hiroshima University Hospital and affiliated hospitals were retrospectively investigated. The associations of clinicopathological parameters with overall survival (OS) and prostate-specific antigen (PSA) progression-free survival (PFS) of alternative FGA-treated patients were analyzed.

RESULTS

Time to CRPC [p = 0.007, hazard ratio (HR) = 4.77], regional lymph node involvement at the diagnosis of CRPC (p = 0.022, HR = 2.42), and PSA-PFS of alternative FGA therapy ≤ 6 months (p = 0.020, HR = 2.39) were identified as prognostic factors using a multivariate analysis. Additionally, Cox proportional hazard models revealed that PSA nadir value > 1 ng/mL during PADT (p = 0.034, HR = 2.40) and time from starting PADT to PSA nadir ≤ 1 year (p = 0.047, HR = 1.85) were predictive factors for worse PSA-PFS in alternative FGA therapy.

CONCLUSIONS

Shorter time to CRPC, regional lymph node involvement, PSA nadir during PADT > 1 ng/mL, and time from starting PADT to PSA nadir ≤ 1 year might suggest the potential benefit of immediate commencement of SGA, compared to FGA administration after nmCRPC diagnosis.

The Importance of Time to Prostate-Specific Antigen (PSA) Nadir after Primary Androgen Deprivation Therapy in Hormone-Naïve Prostate Cancer Patients

Prostate-specific antigen (PSA) is currently the most useful biomarker for detection of prostate cancer (PCa). The ability to measure serum PSA levels has affected all aspects of PCa management over the past two decades. The standard initial systemic therapy for advanced PCa is androgen-deprivation therapy (ADT). Although PCa patients with metastatic disease initially respond well to ADT, they often progress to castration-resistant prostate cancer (CRPC), which has a high mortality rate. We have demonstrated that time to PSA nadir (TTN) after primary ADT is an important early predictor of overall survival and progression-free survival for advanced PCa patients. In in vivo experiments, we demonstrated that the presence of fibroblasts in the PCa tumor microenvironment can prolong the period for serum PSA decline after ADT, and enhance the efficacy of ADT. Clarification of the mechanisms that affect TTN after ADT could be useful to guide selection of optimal PCa treatment strategies. In this review, we discuss recent in vitro and in vivo findings concerning the involvement of stromal–epithelial interactions in the biological mechanism of TTN after ADT to support the novel concept of “tumor regulating fibroblasts”.

Usefulness of Prostate-Specific Antigen Nadir as Predictor of Androgen-Independent Progression of Metastatic Prostate Cancer

The objective of this study was to analyze the value of the nadir level of prostate-specific antigen (PSA) to predict androgen-independent progression (AIP) in metastatic prostate cancer patients after androgen deprivation therapy. In a group of 185 metastatic prostate cancer patients who received androgen deprivation therapy serum PSA was determined every three months until AIP occurred. Multiple regression analysis was performed to define independent clinical and PSA-related predictors of AIP. AIP was assumed to be present after two consecutive increases in serum PSA after the PSA nadir. Independent predictors of the duration of AIP-free survival (less than 12 months versus more than 12 months) were the extent of bone involvement (six or fewer hot spots versus more than six) with an odds ratio (O.R.) of 3.95, Gleason score (7 or less versus more than 7) with an O.R. of 3.47, and PSA nadir (2 μg/L or less versus more than 2 μg/L) with an O.R. of 14.63. AIP was independently predicted by the extent of bone involvement with an O.R. of 1.72, Gleason score with an O.R. of 1.74, PSA nadir with an O.R. of 3.22, and time to reach the PSA nadir (9 months or less versus more than 9 months) with an O.R. of 2.84. When patients were stratified according to these predictors, those with three good prognostic factors had a median AIP-free survival of 58 months while those with two, one or no good prognostic factors had a median AIP-free survival of 19 months, 12 months and 7 months, respectively. We conclude that the PSA nadir seems to be a good predictor of AIP in patients with metastatic prostate cancer after androgen deprivation therapy. Time to PSA nadir, extent of bone involvement and Gleason score are also independent predictors. The combination of these prognostic factors allows to stratify metastatic prostate cancer patients for the prediction of AIP.

Prostate-specific antigen decline pattern in advanced prostate cancer receiving androgen deprivation therapy and relationship with prostate-specific antigen progression

INTRODUCTION

The aim of this study is to evaluate prostate-specific antigen decline pattern including prostate-specific antigen kinetics following androgen deprivation therapy on prostate-specific antigen progression in the patients with advanced prostate cancer.

MATERIALS AND METHODS

Ninety-seven advanced prostate cancer patients receiving maximum androgen deprivation therapy were enrolled in case-control study. Baseline prostate-specific antigen, Gleason Score, bone metastase, nadir prostate-specific antigen, time to nadir prostate-specific antigen, declining slope to nadir prostate-specific antigen, estimated baseline prostate-specific antigen half-time, current prostate-specific antigen, post-nadir prostate-specific antigen time, estimated prostate-specific antigen, estimated decline of baseline prostate-specific antigen as quantitative, and ratio were recorded and calculated.

RESULTS

The ratio of prostate-specific antigen progression was significantly lower at the patients who had slower declining slope to prostate-specific antigen, longer time to nadir prostate-specific antigen, and lower estimated decline ratio of baseline prostate-specific antigen (p: .016, p: .020, and p: .026, respectively).

CONCLUSIONS

The shorter time to nadir prostate-specific antigen following androgen deprivation therapy, faster declining slope to nadir prostate-specific antigen and higher estimated decline ratio of baseline prostate-specific antigen are associated with higher risk of disease progression in patients with hormone-sensitive prostate cancer.

Discovery of prostate specific antigen pattern to predict castration resistant prostate cancer of androgen deprivation therapy

BACKGROUND

Prostate specific antigen (PSA) is an important biomarker to monitor the response to the treatment, but has not been fully utilized as a whole sequence. We used a longitudinal biomarker PSA to discover a new prognostic pattern that predicts castration-resistant prostate cancer (CRPC) after androgen deprivation therapy.

METHODS

We transformed the longitudinal PSA into a discrete sequence, used frequent sequential pattern mining to find candidate patterns from the sequences, and selected the most predictive and informative pattern among the candidates.

RESULTS

Patients were less likely to be CRPC if, after PSA values reach nadir, the PSA decreases more than 0.048 ng/ml during a month, and the decrease occurs again. This pattern significantly increased the accuracy of predicting CRPC by supplementing information provided by existing PSA patterns such as pretreatment PSA.

CONCLUSIONS

This result can help clinicians to stratify men by the risk of CRPC and to determine the patient that needs intensive follow-up.

Clinical outcomes and nadir prostate-specific antigen (PSA) according to initial PSA levels in primary androgen deprivation therapy for metastatic prostate cancer

PURPOSE

To investigate the clinical outcomes of metastatic prostate cancer patients and the relationship between nadir prostate-specific antigen (PSA) levels and different types of primary androgen deprivation therapy (PADT). This study utilized data from the Japan Study Group of Prostate Cancer registry, which is a large, multicenter, population-based database.

METHODS

A total of 2982 patients treated with PADT were enrolled. Kaplan-Meier analysis was used to compare progression-free survival (PFS) and overall survival (OS) in patients treated using combined androgen blockade (CAB) and non-CAB therapies. The relationships between nadir PSA levels and PADT type according to initial serum PSA levels were also investigated.

RESULTS

Among the 2982 enrolled patients, 2101 (70.5 %) were treated with CAB. Although CAB-treated patients had worse clinical characteristics, their probability of PFS and OS was higher compared with those treated with a non-CAB therapy. These results were due to a survival benefit with CAB in patients with an initial PSA level of 500-1000 ng/mL. Nadir PSA levels were significantly lower in CAB patients than in non-CAB patients with comparable initial serum PSA levels.

CONCLUSIONS

A small survival benefit for CAB in metastatic prostate cancer was demonstrated in a Japanese large-scale prospective cohort study. The clinical significance of nadir PSA levels following PADT was evident, but the predictive impact of PSA nadir on OS was different between CAB and non-CAB therapy.

Prostate-specific antigen kinetic profiles during androgen deprivation therapy as prognostic factors in castration-resistant prostate cancer

OBJECTIVE

To identify pretreatment prognostic factors for patients with castration-resistant prostate cancer (CRPC) undergoing docetaxel (DCT) chemotherapy.

MATERIALS AND METHODS

We retrospectively analyzed 102 patients with CRPC who underwent DCT chemotherapy (dosage: 60-75 mg/m(2)) from December 2001 to August 2013. The parameters evaluated as prognostic factors were as follows: age, body mass index, Gleason score, clinical TNM stage, prior radical prostatectomy, prior radiation therapy, performance status, presence of pain, laboratory results at the start of DCT, and prostate-specific antigen (PSA) kinetics during prior androgen deprivation therapy (ADT), including PSA level at the start of ADT (PSA-ADT), PSA half-time (PSAT1/2), time to nadir, PSA level at nadir (PSA-Nadir), duration of nadir, PSA doubling time (PSADT), and PSA level at the start of DCT (PSA-DCT). Univariate and multivariate analyses were performed to identify independent prognostic factors.

RESULTS

Median cancer-specific survival (CSS) duration following CRPC diagnosis was 28.0 months. In univariate analyses, performance status, serum albumin, serum creatinine, PSAT1/2, time to nadir, PSA-Nadir, duration of nadir, PSADT, and PSA-DCT showed a potential association with prognosis (P<0.001-0.077). Multivariate analyses of these parameters showed that performance status (hazard ratio [HR] = 0.046; P = 0.046), serum creatinine (HR = 3.028; P = 0.036), PSAT1/2 (HR = 0.172; P = 0.007), PSA-Nadir (HR = 4.884; P = 0.033), PSADT (HR = 0.148; P<0.001), and PSA-DCT (HR = 5.222; P = 0.004) remained independent predictors of CSS in CRPC.

CONCLUSIONS

PSA kinetic parameters measured during prior ADT are significant surrogate markers predicting CSS in patients undergoing DCT chemotherapy for CRPC.

Constitutively active AR-V7 plays an essential role in the development and progression of castration-resistant prostate cancer

This study aimed to investigate the role of AR-V7 in development of castration-resistant prostate cancer (CRPC) and to determine whether the AR-V7 expression in CRPC tissues can predict cancer-specific survival. We enrolled 100 localized prostate cancer (PCa) (cohort 1), 104 newly diagnosed metastatic PCa (cohort 2), and 46 CRPC (cohort 3) patients treated at our institution. The expression of AR-V7 in PCa was assessed by immunohistochemistry. Cox regression models were used to evaluate the predictive role of all covariates for the development of CRPC in cohort 2 and for cancer-specific survival in cohort 3. Time to CRPC and cancer-specific survival curves were estimated using the Kaplan-Meier method. AR-V7 expression rate in cohort 3 was significantly elevated compared with other two cohorts (p < 0.001). Multivariate analysis revealed that AR-V7 was an independent predictive factor for CRPC development (HR = 2.627, p = 0.001) and for cancer specific survival (HR = 2.247, p = 0.033). Furthermore, the AR-V7 expression was associated with shorter survival in CRPC patients. Our results demonstrated protein AR-V7 levels in primary tumors can be used as a predictive marker for the development of CRPC and as a prognostic factor in CRPC patients. Therapy targeting AR-V7 may help prevent PCa progression and improve the prognosis of CRPC patients.

Survival outcomes of Chinese metastatic prostate cancer patients following primary androgen deprivation therapy in relation to prostate-specific antigen nadir level

AIM

To evaluate the progression-free survival (PFS), cancer-specific survival (CSS) and overall survival (OS) of Chinese metastatic prostate cancer patients following primary androgen deprivation therapy (ADT) in relation to prostate-specific antigen (PSA) nadir level.

METHODS

All Chinese prostate cancer patients with bone metastases who were treated with primary ADT from 2000 to 2009 were included. Patients' and disease characteristics were recorded. Patients were categorized into two PSA nadir groups (≤1.0 and >1.0 ng/mL). Associations of PSA nadir with PFS, CSS and OS were analyzed with Kaplan-Meier and Cox regression analyses. The survival outcomes of the two PSA nadir groups were presented.

RESULTS

Four hundred nineteen patients were included in the study. PSA nadir appeared to be a good predictor for PFS (hazard ratio [HR] 1.86, 95% confidence interval [CI] 1.35-2.56, P < 0.001), CSS (HR 1.60, 95% CI 0.98-2.64, P = 0.063) and OS (HR 1.77, 95% CI 1.20-2.41, P < 0.001) upon multivariate Cox regression analyses. In the PSA nadir groups of ≤1.0 and >1.0 ng/mL, the median PFS were 15 and 10 months, and the 1-year PFS rates were 64% and 40%, respectively; the median CSS were 42 and 27 months, and the 5-year OS rates were 53% and 28%, respectively; and the median OS were 41 and 24 months, and the 5-year OS rates were 45% and 19%, respectively.

CONCLUSIONS

Higher PSA nadir was associated with shorter PFS, CSS and OS in Chinese metastatic prostate cancer patients following primary ADT. The survival outcomes may serve as references in deciding the best treatment strategy in Chinese prostate cancer patients.

A critical review of the analytical approaches for circulating tumor biomarker kinetics during treatment

Changes in serum tumor biomarkers may indicate treatment efficacy. Traditional tumor markers may soon be replaced by novel serum biomarkers, such as circulating tumor cells (CTCs) or circulating tumor nucleic acids. Given their promising predictive values, studies of their kinetics are warranted. Many methodologies meant to assess kinetics of traditional marker kinetics during anticancer treatment have been reported. Here, we review the methodologies, the advantages and the limitations of the analytical approaches reported in the literature. Strategies based on a single time point were first used (baseline value, normalization, nadir, threshold at a time t), followed by approaches based on two or more time points [half-life (HL), percentage decrease, time-to-events…]. Heterogeneities in methodologies and lack of consideration of inter- and intra-individual variability may account for the inconsistencies and the poor utility in routine. More recently, strategies based on a population kinetics approach and mathematical modeling have been reported. The identification of equations describing individual kinetic profiles of biomarkers may be an alternative strategy despite its complexity and higher number of necessary measurements. Validation studies are required. Efforts should be made to standardize biomarker kinetic analysis methodologies to ensure the optimized development of novel serum biomarkers and avoid the pitfalls of traditional markers.

Nadir PSA level and time to nadir PSA are prognostic factors in patients with metastatic prostate cancer

Background

Primary androgen deprivation therapy (PADT) is the most effective systemic therapy for patients with metastatic prostate cancer. Nevertheless, once PSA progression develops, the prognosis is serious and mortal. We sought to identify factors that predicted the prognosis in a series of patients with metastatic prostate cancer.

Methods

Two-hundred eighty-six metastatic prostate cancer patients who received PADT from 1998 to 2005 in Nara Uro-Oncology Research Group were enrolled. The log-rank test and Cox’s proportional hazards model were used to determine the predictive factors for prognosis; rate of castration-resistant prostate cancer (CRPC) and overall survival.

Results

The median age, follow-up period and PSA level at diagnosis were 73 years, 47 months and 174 ng/mL, respectively. The 5-year overall survival rate was 63.0%. The multivariable analysis showed that Gleason score (Hazard ratio [HR]:1.362; 95% confidence interval [C.I.], 1.023-1.813), nadir PSA (HR:6.332; 95% C.I., 4.006-9.861) and time from PADT to nadir (HR:4.408; 95% C.I., 3.099-6.271) were independent prognostic factors of the incidence of CRPC. The independent parameters in the multivariate analysis that predicted overall survival were nadir PSA (HR:5.221; 95% C.I., 2.757-9.889) and time from PADT to nadir (HR:4.008; 95% C.I., 2.137-7.517).

Conclusions

Nadir PSA and time from PADT to nadir were factors that affect both CRPC and overall survival in a cohort of patients with metastatic prostate cancer. Lower nadir PSA level and longer time from PADT to nadir were good for survival and progression.

Nadir prostate-specific antigen (PSA) level and time to PSA nadir following primary androgen deprivation therapy as independent prognostic factors in a Japanese large-scale prospective cohort study (J-CaP)

PURPOSE

The aim of this study was to investigate whether nadir prostate-specific antigen (PSA) level and time to PSA nadir (TTN) are independent prognostic factors equivalent to the pretreatment factors in the data of the Japan Study Group of Prostate Cancer registry, which is a large, multicenter, population-based database of patients undergoing primary androgen deprivation therapy (PADT).

METHODS

A total of 10,958 patients treated with PADT were enrolled into the present study. Univariate and multivariate Cox proportional hazards regression analysis and Kaplan-Meier analysis were used to evaluate the associations of PSA nadir level and TTN with progression-free survival (PFS) and overall survival (OS), adjusting for the pretreatment factors adopted in the Japan Cancer of the Prostate Risk Assessment (J-CAPRA) score.

RESULTS

Of the 10,958 patients, 3,451 (31.5%) had lymph node and/or distant metastases. The median PSA level was 27.0 ng/ml before treatment, and the nadir PSA level in 6,983 patients (63.7%) reached below 0.2 ng/ml. Disease progression occurred in 4,736 cases, and 2,163 patients died during a mean follow-up period of 3.86 years. Nadir PSA level and TTN were independent prognostic factors, similar to the pretreatment factors adopted in the J-CAPRA score. The probabilities of PFS and OS showed significant differences among the groups categorized by the combination of nadir PSA level and TTN in all J-CAPRA risk stratifications.

CONCLUSIONS

The present study demonstrated that nadir PSA level and TTN are strong predictors in patients undergoing PADT in a large-scale prospective cohort study.

The utility of prostate-specific antigen in the management of advanced prostate cancer

To review current prostate-specific antigen (PSA) metrics used in monitoring treatment of advanced prostate cancer, with a specific focus on castration-resistant prostate cancer (CRPC) therapies. Explore what is known about the correlation between PSA and androgen levels as well as underlying reasons for persistent PSA expression and serum elevation in CRPC, and outline suggestions for use of PSA in managing patients with advanced prostate cancer. A comprehensive search of the PubMed database for English language articles through April 2012 was performed using the following Medical Subject Headings (MeSH) keywords or terms, alone or in combination: 'prostate cancer'; 'prostate cancer treatment'; 'prostate cancer outcomes'; 'prostate-specific antigen'; 'androgen receptor'; 'advanced prostate cancer'; 'castration-resistant prostate cancer'; 'biomarkers'. Bibliographies of relevant articles were searched for additional references. Relevant medical society and regulatory agency web sites from the USA and Europe were accessed for issued guidance on PSA use. PSA doubling time (PSADT) is a useful metric for determining which patients should be considered for androgen-deprivation therapy (ADT) after failing local treatment or for second-line therapies after failing ADT. However, it is not a validated surrogate for survival and no therapy has received regulatory approval based upon PSADT characteristics. PSA nadir and time-to-nadir have been identified as possible prognostic markers for patients receiving ADT. There is no universally accepted definition for PSA progression, nor is PSA progression a regulatory-approved surrogate for clinical progression in drug approval trials. PSA responses to second-line therapies can vary and are not considered by regulatory agencies as valid surrogates for clinical endpoints, so they must be assessed in the context of each individual therapy and trial design. PSA expression in CRPC is often a reflection of persistent androgen receptor activity. While we can provide guidance for use of PSA monitoring in managing patients with advanced prostate cancer based on the data at hand, there is an urgent need for prospective analyses of refined PSA metrics in conjunction with newer prostate cancer biomarkers in clinical trials to provide stronger evidence for their roles as surrogate endpoints.

Cutoff value of time to prostate-specific antigen nadir is inversely correlated with disease progression in advanced prostate cancer

To identify the early predictor of progression to castration-resistant prostate cancer (CRPC) for different stage of advanced PC patients, we focused on time to prostate-specific antigen (PSA) nadir following primary androgen deprivation therapy (PADT). We reviewed 184 advanced (locally advanced and metastatic) PC patients (101 patients with bone metastasis (BM) and 83 patients without BM at presentation) who had received PADT at our institution. We evaluated laboratory data, pathological results, and the influence of PSA kinetics impact on disease progression. The progression rates were analyzed with reference to the nadir PSA level and time to PSA nadir (TTN) following PADT by Kaplan-Meier method. In all, 103 patients (56%) progressed to CRPC. Nadir PSA lower than 0.2 ng/ml (nadir ≤0.2) during PADT was observed in 114 patients (62%). Median TTN was 8.5 months in patients with BM and 11.5 months in patients without BM. Multivariate analysis revealed that nadir ≤0.2 following PADT (P<0.001), longer TTN (>8 months) (P<0.001), extent of disease on bone scan grade (P=0.02), and T stage (P=0.04) in BM group and nadir ≤0.2 following PADT (P<0.001), longer TTN (>11 months) (P<0.001), and T stage (P=0.03) in without BM group were independent prognostic factors for progression. In both groups, longer TTN identified patients with prolonged progression-free survival in both nadir ≤0.2 and >0.2 nadir levels. Longer TTN is strongly associated with a low risk of disease progression, and the cutoff value of TTN could be inversely correlated with disease progression.

Prostate-specific antigen nadir and time to prostate-specific antigen nadir following maximal androgen blockade independently predict prognosis in patients with metastatic prostate cancer

Purpose

To evaluate the influence of prostate-specific antigen (PSA) kinetics following maximal androgen blockade (MAB) on disease progression and cancer-specific survival in patients with metastatic, hormone-sensitive prostate cancer.

Materials and Methods

One hundred thirty-one patients with metastatic, hormone-sensitive prostate cancer treated with MAB at our institution were included in this study. Patients' characteristics, PSA at MAB initiation, PSA nadir, time to PSA nadir (TTN), and PSA decline were analyzed by using univariate and multivariate analysis.

Results

At a median follow-up of 30 months, 97 patients (74.0%) showed disease progression and 65 patients (49.6%) died. Fifty-nine patients (45.0%) died from prostate cancer. In the univariate analysis, PSA at MAB initiation, PSA nadir, TTN, and PSA decline were significant predictors of progression-free survival. Also, PSA nadir, TTN, and PSA decline were significant predictors of cancer-specific survival. In the multivariate analysis, higher PSA nadir (≥0.2 ng/ml) and shorter TTN (<8 months) were independent predictors of shorter progression-free and cancer-specific survival. In the combined analysis of PSA nadir and TTN, patients with higher PSA nadir and shorter TTN had the worst progression-free survival (hazard ratio [HR], 14.098; p<0.001) and cancer-specific survival (HR, 14.050; p<0.001) compared with those with lower PSA nadir and longer TTN.

Conclusions

Our results suggest that higher PSA nadir level and shorter TTN following MAB are associated with higher risk of disease progression and poorer survival in patients with metastatic, hormone-sensitive prostate cancer. Furthermore, these two variables have a synergistic effect on the outcome.

Peripheral blood reverse transcription PCR assay for prostate stem cell antigen correlates with androgen-independent progression in advanced prostate cancer

Recent studies show that prostate stem cell antigen (PSCA) mRNA positivity in peripheral blood correlates with disease progression in prostate cancer (PCa). Our study is to evaluate the association between peripheral blood PSCA status and androgen-independent progression (AIP) in a cohort of patients with advanced PCa under androgen deprivation therapy (ADT). PSCA mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR) assay in peripheral blood samples from 116 patients with locally advanced or metastatic PCa who were treated with primary ADT and from 40 healthy controls. The Kaplan-Meier and the Cox proportional hazards methods were used to assess potential predictors of AIP. Pretreatment RT-PCR-PSCA was positive in 37 (31.9%) of 116 patients. All healthy volunteers were negative for PSCA mRNA. Although seven (14.9%) of 47 patients with Gleason score ≤7 were PSCA positive, 30 (43.5%) of 69 patients with Gleason score >7 were PSCA positive (p = 0.016). PSCA mRNA was detected in 28 (58.3%) of 48 patients with metastatic PCa, compared to nine (13.2%) of 68 patients with locally advanced disease (p = 0.012). AIP developed in 59 (50.9%) patients during a median follow-up period of 35.4 months (range: 4-78 months). Patients with PSCA negativity experienced significantly longer remissions compared to those with PSCA positivity (log-rank test: p < 0.001). Multivariate Cox regression analysis further demonstrated that PSCA positivity had a significantly increased risk of AIP (HR = 4.303, 95% CI: 3.761-7.482, p < 0.001). Pretreatment RT-PCR PSCA positivity in peripheral blood independently signals the presence of AIP in patients with advanced PCa treated with ADT.

Serum early prostate cancer antigen (EPCA) level and its association with disease progression in prostate cancer in a Chinese population

BACKGROUND

Early prostate cancer antigen (EPCA) has been shown a prostate cancer (PCa)-associated nuclear matrix protein, however, its serum status and prognostic power in PCa are unknown. The goals of this study are to measure serum EPCA levels in a cohort of patients with PCa prior to the treatment, and to evaluate the clinical value of serum EPCA.

METHODS

Pretreatment serum EPCA levels were determined with an ELISA in 77 patients with clinically localized PCa who underwent radical prostatectomy and 51 patients with locally advanced or metastatic disease who received primary androgen deprivation therapy, and were correlated with clinicopathological variables and disease progression. Serum EPCA levels were also examined in 40 healthy controls.

RESULTS

Pretreatment mean serum EPCA levels were significantly higher in PCa patients than in controls (16.84 ± 7.60 ng/ml vs. 4.12 ± 2.05 ng/ml, P<0.001). Patients with locally advanced and metastatic PCa had significantly higher serum EPCA level than those with clinically localized PCa (22.93 ± 5.28 ng/ml and 29.41 ± 8.47 ng/ml vs. 15.17 ± 6.03 ng/ml, P = 0.014 and P<0.001, respectively). Significantly elevated EPCA level was also found in metastatic PCa compared with locally advanced disease (P < 0.001). Increased serum EPCA levels were significantly and positively correlated with Gleason score and clinical stage, but not with PSA levels and age. On multivariate analysis, pretreatment serum EPCA level held the most significantly predictive value for the biochemical recurrence and androgen-independent progression among pretreatment variables (HR = 4.860, P<0.001 and HR = 5.418, P<0.001, respectively).

CONCLUSIONS

Serum EPCA level is markedly elevated in PCa. Pretreatment serum EPCA level correlates significantly with the poor prognosis, showing prediction potential for PCa progression.

Clinical efficacy of primary combined androgen blockade for Japanese men with clinically localized prostate cancer unsuitable for local definitive treatment: a single institution experience

BACKGROUND

Primary hormonal therapy has been mostly used for patients with advanced prostate cancer, as international guidelines do not recommend its use for patients at earlier disease stages. However, there seems to be a discrepancy between the guideline recommendations and clinical practice on the use of primary androgen deprivation therapy for localized prostate cancer in Japan. Therefore, we retrospectively analyzed a single-institution experience in primary combined androgen blockade (CAB) for localized prostate cancer.

PATIENTS AND METHODS

The study included 187 patients with T1c-T3a prostate cancer unsuitable for local definitive treatment and treated with primary CAB. Clinical outcomes, predictive factors of PSA relapse and adverse events were investigated.

RESULTS

The progression-free, disease-specific, and overall survival rates of all patients at 5 years were 63.0, 99.4 and 95.9%, respectively. Of the several parameters isolated as predictors of prostate-specific antigen (PSA) progression, nadir PSA level and the percentage of positive biopsy cores (%PBC) remained as independent prognostic factors on multivariate analysis. Toxicities were mild to moderate and well tolerated.

CONCLUSIONS

Primary CAB treatment brought initial disease control without relapse in the majority of our selected cases. The %PBC may help predict time to relapse in the pretreatment setting. The results implicate that CAB can be an option as a primary treatment for clinically localized prostate cancer unsuitable for local definitive treatment. To confirm the exact efficacy of primary CAB, these findings should be reviewed in a large cohort of patients with long-term follow-up from various viewpoints, including disease control, toxicities, quality-of-life and medical cost.

[Prostate specific antigen: utilization modalities and interpretation]

The prostate specific antigen test has become one of the most popular blood test. However, its result should be analyzed with caution due to physiologic variability. The PSA test is performed for prostate cancer (PC) screening or for post-treatment PC surveillance. According to the applied treatment (surgery or radiation therapy with or without hormonal therapy), PSA analysis can confirm biochemical control or relapse. New PSA data regarding the evolution of this biomarker during the surveillance (PSA doubling time and PSA velocity) are now important to consider in case of biochemical relapse.

Prostate-specific antigen and prostate cancer: prediction, detection and monitoring

Testing for prostate-specific antigen (PSA) has profoundly affected the diagnosis and treatment of prostate cancer. PSA testing has enabled physicians to detect prostate tumours while they are still small, low-grade and localized. This very ability has, however, created controversy over whether we are now diagnosing and treating insignificant cancers. PSA testing has also transformed the monitoring of treatment response and detection of disease recurrence. Much current research is directed at establishing the most appropriate uses of PSA testing and at developing methods to improve on the conventional PSA test.

Tumor volume changes on 1.5 tesla endorectal MRI during neoadjuvant androgen suppression therapy for higher-risk prostate cancer and recurrence in men treated using radiation therapy results of the phase II CALGB 9682 study

PURPOSE

We prospectively determined whether the change in tumor volume (TV) during 2 months of neoadjuvant androgen suppression therapy (nAST) measured using conventional 1.5 Tesla endorectal magnetic resonance imaging (eMRI) was associated with the risk of recurrence after radiation (RT) and 6 months of AST.

PATIENTS AND METHODS

Between 1997 and 2001, 180 men with clinical stage T1c-T3cN0M0 adenocarcinoma of the prostate were registered. Fifteen were found to be ineligible and the institutional MR radiologist could not assess the TV in 32, leaving 133 for analysis. Multivariable Cox regression analysis was used to assess whether a significant association existed between eMRI-defined TV progression during nAST and time to recurrence adjusting for prostate-specific antigen (PSA) level, Gleason score (8 to 10 or 7 vs. 6 or less) and stage (T3 vs. T1-2).

RESULTS

After a median follow up of 6.7 years and adjusting for known prognostic factors, there was a significant increase in the risk of PSA failure (HR, 2.3 [95% CI, 1.1-4.5; p = 0.025) in men with eMRI-defined TV progression during nAST. Specifically, adjusted estimates of PSA failure were significantly higher (p = 0.032) in men with, compared with men without, eMRI-defined TV progression reaching 38% vs. 19%, respectively, by 5 years.

CONCLUSION

Eradicating intraprostatic hormone refractory prostate cancer (HRPC) by maximizing local control and randomized trials assessing whether survival is improved when agents active against HRPC are combined with maximal local therapy are needed in men who progress based on eMRI during nAST.

Primary hormone therapy for locally advanced prostate cancer

Locally advanced prostate cancer is a treatment dilemma. As with prostate cancer in general, there is no clear evidence that aggressive intervention (ie, surgery or radiation) is superior to noninvasive interventions (eg, delayed treatment or androgen ablation). Because patients with locally advanced prostate cancer have a high risk of local and systemic recurrence, there is some argument to proceed with androgen ablation as the sole modality of treatment. The data using this approach are limited, but an understanding of the degree and duration of response is helpful in selecting patients for primary androgen ablation.

Predictors of mortality after androgen-deprivation therapy in patients with rapidly rising prostate-specific antigen levels after local therapy for prostate cancer

BACKGROUND

The authors identified biochemical and pathologic factors that were associated significantly with prostate cancer-specific mortality (PCSM) after androgen deprivation therapy (ADT) in men who had rapidly rising prostate-specific antigen (PSA) levels after they received local treatment.

METHODS

The study population consisted of 67 patients who had a PSA doubling time (DT) < or =6 months after radical prostatectomy (n = 50 patients) or external beam radiation therapy (n = 17 patients) for localized prostate cancer. Multivariate Cox proportional hazards regression analysis was used to evaluate whether the interval to PSA failure, pre-ADT PSA DT, PSA level at the time of ADT initiation, time to PSA nadir, PSA nadir after 8 months on ADT, and Gleason score were associated significantly with the time to PCSM 8 months after the initiation of ADT.

RESULTS

: A PSA nadir >0.2 ng/mL (adjusted hazard ratio [HR], 8.0; 95% confidence interval [95% CI], 1.7-38.7; P = 0.009) and a Gleason score > or =8 (adjusted HR, 5.2; 95% CI, 1.3-20.6; P = 0.02) were associated significantly with a short time to PCSM. The cumulative incidence estimates of 3-year PCSM were 5.8% versus 50.9% for patients with a PSA nadir < or =0.2 ng/mL versus >0.2 ng/mL, respectively, and 10.8% versus 35.8% for patients who had tumors with a Gleason score < or =7 versus > or =8, respectively.

CONCLUSIONS

: Among men with a PSA DT < or =6 months, both a PSA nadir >0.2 ng/mL after ADT and a Gleason score > or =8 cancer identified men who were at high risk for PCSM. These men would be ideal candidates for Phase III studies that evaluate the impact on survival of new systemic therapies for prostate cancer.

Relative importance of PSA in prostate cancer treatment

METHODS AND MATERIALS

A retrospective study was conducted to (1) determine the relationship between baseline prostate-specific antigen (PSA) levels and initial treatment decisions for prostate cancer (surgery, hormone therapy, radiation, or watchful waiting) and (2) estimate the impact of PSA progression (doubling or three consecutive rises) on subsequent treatment decisions. Patient records (n=1116) from three community urology practices and a large academic health system were reviewed. Multivariate models were fitted to assess the relationship between initial treatment and baseline PSA, Gleason score, race, number of comorbid conditions and age and between PSA progression and time to subsequent therapy (adjusted for other factors).

RESULTS

Baseline PSA was a significant predictor of initial treatment among men with localized disease with the likelihood of hormone therapy increasing with higher PSA levels and the likelihood of surgery decreasing steadily with higher PSA levels. PSA was the strongest predictor of hormone therapy as first choice followed by age. Age followed by PSA was the strongest predictor of surgery as first treatment as well as radiation therapy. Initial PSA levels did not predict the choice of watchful waiting. Patients with PSA progression were eight times (95% CI: 5.3-12.1) more likely to initiate a subsequent therapy than patients who did not have PSA progression when controlling for other predictors.

CONCLUSIONS

In clinical practice, PSA significantly impacts the urologist's primary therapy choice and determines when they introduce subsequent treatments.

LIMITATIONS IN THE USE OF SERUM PROSTATE SPECIFIC ANTIGEN LEVELS TO MONITOR PATIENTS AFTER TREATMENT FOR PROSTATE CANCER

PURPOSE

We reviewed the literature to help clarify the benefits and/or hazards associated with monitoring serum prostate specific antigen (PSA) after treatment with surgery or radiation therapy (RT) for nonmetastatic prostate cancer.

MATERIALS AND METHODS

A search was performed for 1990 to 2004 using the MEDLINE database, CancerLit database and reference lists of relevant studies to obtain articles addressing the use of serum PSA to follow patients after treatment for prostate cancer. Studies were reviewed to determine 1) if serial PSA monitoring provides an early and accurate surrogate assessment of cancer cure or treatment failure, 2) if any pattern in the PSA profile after treatment provides conclusive evidence of early local vs systemic failure, 3) the magnitude of the lead time to clinical failure that serial PSA monitoring may provide and 4) if the early identification of biochemical failure (BF) with earlier intervention improves outcome.

RESULTS

Although a lower PSA nadir after treatment with RT has been associated with cancer cure, 5% to 25% of patients ultimately have failure (beyond 5 years) even with the most optimal biochemical response. The most appropriate BF definitions to use after treatment for prostate cancer with RT remains controversial due to substantial differences in their accuracy, sensitivity, specificity and positive predictive value for clinical outcome. No pattern of PSA kinetics after treatment has conclusively been associated with a specific recurrence site. Biochemical failure definitions in patients treated with RT appear to provide a 6 to 18 month lead time to clinical failure but there are only limited published data to suggest that early intervention of any type (androgen deprivation, RT, surgery, etc) impacts survival.

CONCLUSIONS

The overall benefit of monitoring serum PSA after treatment for prostate cancer remains controversial. Considering the potential dangers associated with incorrectly assuming the efficacy of new forms of treatment, the toxicity of administering salvage therapies of uncertain efficacy after BF has been identified and the anxiety associated with tracking posttreatment serum PSA, additional studies must be done to determine the appropriate use of this marker in properly treating patients after therapy.

Androgen deprivation for minimal metastatic disease: Threshold for achieving undetectable prostate-specific antigen

OBJECTIVES

To develop objective measures to select systemic therapies for study in large-scale trials for patients with lesser tumor burdens, we explored prostate-specific antigen (PSA) changes after androgen ablation in patients with disease progression after treatment of localized disease. Long-term follow-up of trials incorporating androgen-deprivation with local therapy have shown improved survival relative to local therapy alone. This suggests that the benchmark for treatment of minimal metastatic disease can be cure.

METHODS

Patients with a rising PSA level with or without clinical metastases after local therapy who received androgen deprivation at Memorial Sloan-Kettering Cancer were identified from two institutional databases. The primary outcome was the proportion achieving an undetectable PSA level, and the pretreatment parameters associated with this endpoint were evaluated.

RESULTS

A total of 130 patients who received androgen ablation and were followed up at Memorial Sloan-Kettering Cancer Center were identified. Overall, 31 (57%) of 54 (95% confidence interval 44% to 71%) patients with a rising PSA level alone and 28 (37%) of 76 (95% confidence interval 26% to 47%) patients with a rising PSA level and clinical metastases achieved an undetectable PSA level after androgen ablation (P = 0.02). The PSA level at the start of androgen ablation and the presence of metastases were the most significant predictive factors.

CONCLUSIONS

The probability of achieving an undetectable PSA level varied inversely with the disease extent. Although achieving an undetectable PSA level does not mean that a patient has been cured, it does establish an endpoint that can be used to identify approaches worthy of study in the Phase III setting.