The change of PSA doubling time and its association with disease progression in patients with biochemically relapsed prostate cancer treated with intermittent androgen deprivation

Towards improved diagnosis: radiomics and quantitative biomarkers in 18F-PSMA-1007 and 18F-fluorocholine PET/CT for prostate cancer recurrence

OBJECTIVE

This study compared the radiomic features and quantitative biomarkers of 18F-PSMA-1007 [prostate-specific membrane antigen (PSMA)] and 18F-fluorocholine (FCH) PET/computed tomography (CT) in prostate cancer patients with biochemical recurrence (BCR) enrolled in the phase 3, prospective, multicenter BIO-CT-001 trial.

METHODS

A total of 106 patients with BCR, who had undergone primary definitive treatment for prostate cancer, were recruited to this prospective study. All patients underwent one PSMA and one FCH PET/CT examination in randomized order within 10 days. They were followed up for a minimum of 6 months. Pathology, prostate-specific antigen (PSA), PSA doubling time, PSA velocity, and previous or ongoing treatment were analyzed. Using LifeX software, standardized uptake value (SUV) maximum, SUVmean, PSMA and choline total volume (PSMA-TV/FCH-TV), and total lesion PSMA and choline (TL-PSMA/TL-FCH) of all identified metastatic lesions in both tracers were calculated.

RESULTS

Of the 286 lesions identified, the majority 140 (49%) were lymph node metastases, 118 (41.2%) were bone metastases and 28 lesions (9.8%) were locoregional recurrences of prostate cancer. The median SUVmax value was significantly higher for 18F-PSMA compared with FCH for all 286 lesions (8.26 vs. 4.99, respectively, P < 0.001). There were statistically significant differences in median SUVmean, TL-PSMA/FCH, and PSMA/FCH-TV as per table 2 between the two radiotracers (4.29 vs. 2.92, 1.97 vs. 1.53, and 7.31 vs. 4.37, respectively, P < 0.001). The correlation between SUVmean/SUVmax and PSA level was moderate, both for 18F-PSMA (r = 0.44, P < 0.001; r = 0.44, P < 0.001) and FCH (r = 0.35, P < 0.001; r = 0.41, P < 0.001). TL-PSMA/FCH demonstrated statistically significant positive correlations with both PSA level and PSA velocity for both 18F-PSMA (r = 0.56, P < 0.001; r = 0.57, P < 0.001) and FCH (r = 0.49, P < 0.001; r = 0.51, P < 0.001). While patients who received hormone therapy showed higher median SUVmax values for both radiotracers compared with those who did not, the difference was statistically significant only for 18F-PSMA (P < 0.05).

CONCLUSION

Our analysis using both radiomic features and quantitative biomarkers demonstrated the improved performance of 18F-PSMA-1007 compared with FCH in identifying metastatic lesions in prostate cancer patients with BCR.

Association of PSA kinetics after testosterone recovery with subsequent recurrence: secondary analysis of a phase III randomized controlled trial

PURPOSE

After cessation of androgen deprivation therapy (ADT), testosterone gradually recovers to supracastrate levels (> 50 ng/dL). After this, rises in prostate-specific antigen (PSA) are often seen. However, it remains unknown whether early PSA kinetics after testosterone recovery are associated with subsequent biochemical recurrence (BCR).

METHODS

We performed a secondary analysis of a phase III randomized controlled trial in which newly diagnosed localized prostate cancer patients were randomly allocated to ADT for 6 months starting 4 months prior to or simultaneously with prostate RT. We calculated the PSA doubling time (PSADT) based on PSA values up to 18 months after supracastrate testosterone recovery. Competing risk regression was used to evaluate the association of PSADT with relative incidence of BCR, considering deaths as competing events.

RESULTS

Overall, 313 patients were eligible. Median PSADT was 8 months. Cumulative incidence of BCR at 10 years from supracastrate testosterone recovery was 19% and 11% in patients with PSADT < 8 months and ≥ 8 months (p = 0.03). Compared to patients with PSADT of < 4 months, patients with higher PSADT (sHR for PSADT 4 to < 8 months: 0.36 [95% CI 0.16-0.82]; 8 to < 12 months: 0.26 [0.08-0.91]; ≥ 12 months: 0.20 [0.07-0.56]) had lower risk of relative incidence of BCR.

CONCLUSIONS

Early PSA kinetics, within 18 months of recovery of testosterone to a supracastrate level, can predict for subsequent BCR. Taking account of early changes in PSA after testosterone recovery may allow for recognition of potential failures earlier in the disease course and thereby permit superior personalization of treatment.

Prediction of disease progression indicators in prostate cancer patients receiving HDR-brachytherapy using Raman spectroscopy and semi-supervised learning: a pilot study

This work combines Raman spectroscopy (RS) with supervised learning methods-group and basis restricted non-negative matrix factorisation (GBR-NMF) and linear discriminant analysis (LDA)-to aid in the prediction of clinical indicators of disease progression in a cohort of 9 patients receiving high dose rate brachytherapy (HDR-BT) as the primary treatment for intermediate risk (D'Amico) prostate adenocarcinoma. The combination of Raman spectroscopy and GBR-NMF-sparseLDA modelling allowed for the prediction of the following clinical information; Gleason score, cancer of the prostate risk assessment (CAPRA) score of pre-treatment biopsies and a Ki67 score of < 3.5% or > 3.5% in post treatment biopsies. The three clinical indicators of disease progression investigated in this study were predicted using a single set of Raman spectral data acquired from each individual biopsy, obtained pre HDR-BT treatment. This work highlights the potential of RS, combined with supervised learning, as a tool for the prediction of multiple types of clinically relevant information to be acquired simultaneously using pre-treatment biopsies, therefore opening up the potential for avoiding the need for multiple immunohistochemistry (IHC) staining procedures (H&E, Ki67) and blood sample analysis (PSA) to aid in CAPRA scoring.

The presence of polymorphisms in genes controlling neurotransmitter metabolism and disease prognosis in patients with prostate cancer: a possible link with schizophrenia

Polymorphisms of neurotransmitter metabolism genes were studied in patients with prostate cancer (PC) characterized by either reduced or extended serum prostate-specific antigen doubling time (PSADT) corresponding to unfavorable and favorable disease prognosis respectively. The ‘unfavorable prognosis’ group (40 cases) was defined by PSADT ≤ 2 months, whereas patients in the ‘favorable prognosis’ group (67 cases) had PSADT ≥ 30 months. The following gene polymorphisms known to be associated with neuropsychiatric disorders were investigated: a) the STin2 VNTR in the serotonin transporter SLC6A4 gene; b) the 30-bp VNTR in the monoamine oxidase A MAOA gene; c) the Val158Met polymorphism in the catechol-ortho-methyltransferase COMT gene; d) the promoter region C-521T polymorphism and the 48 VNTR in the third exon of the dopamine receptor DRD4 gene.

The STin2 12R/10R variant of the SLC6A4 gene (OR = 2.278; 95% CI = 0.953–5.444) and the -521T/T homozygosity of the DRD4 gene (OR = 1.579; 95% CI = 0.663–3.761) tended to be overrepresented in PC patients with unfavorable disease prognosis. These gene variants are regarded as protective against schizophrenia, and the observed trend may be directly related to a reduced PC risk described for schizophrenia patients. These results warrant further investigation of the potential role of neurotransmitter metabolism gene polymorphisms in PC pathogenesis.

Optimal PSA Threshold for Androgen-Deprivation Therapy in Patients with Prostate Cancer following Radical Prostatectomy and Adjuvant Radiation Therapy

PURPOSE

The benefits of early administration of androgen-deprivation therapy (ADT) in patients with prostate-specific antigen (PSA)-only recurrent prostate cancer (PCa) following radical prostatectomy (RP) are controversial. We investigated the impact of early versus delayed ADT on survival outcomes in patients with non-metastatic, localized or locally advanced PCa who received radiation therapy (RT) following RP and later developed distant metastasis.

MATERIALS AND METHODS

A retrospective analysis was performed on 69 patients with non-metastatic, localized or locally advanced PCa who received RT following RP and later developed distant metastasis between January 2006 and December 2012. Patients were stratified according to the level of PSA at which ADT was administered (<2 ng/mL vs. ≥2 ng/mL). Study endpoints were progression to castration-resistant prostate cancer (CRPC)-free survival and cancer-specific survival (CSS).

RESULTS

Patients were stratified according to the criteria of 2 ng/mL of PSA at which ADT was administered, based on the Youden sensitivity analysis. Delayed ADT at PSA ≥2 ng/mL was an independent prognosticator of cancer-specific mortality (p=0.047), and a marginally significant prognosticator of progression to CRPC (p=0.051). During the median follow-up of 81.0 (interquartile range 54.2-115.7) months, patients who received early ADT at PSA <2 ng/mL had significantly higher CSS rates compared to patients who received delayed ADT at PSA ≥2 ng/mL (p=0.002). Progression to CRPC-free survival was comparable between the two groups (p=0.331).

CONCLUSION

Early ADT at the PSA level of less than 2 ng/mL confers CSS benefits in patients with localized or locally advanced PCa who were previously treated with RP.

Measuring testosterone and testosterone replacement therapy in men receiving androgen deprivation therapy for prostate cancer: A survey of UK uro-oncologists' opinions and practice

AIM

To explore the practice and attitudes of uro-oncologists in the UK regarding monitoring testosterone levels and the use of testosterone replacement therapy (TRT) in their prostate cancer patients treated with androgen deprivation therapy (ADT).

METHODS

An expert-devised online questionnaire was completed by the members of the British Uro-oncology Group (BUG).

RESULTS

Of 160 uro-oncologists invited, 84 completed the questionnaire. Before initiating ADT in patients with non-metastatic prostate cancer, only 45% of respondents measured testosterone levels and 61% did not measure testosterone at all during ADT in the adjuvant or neoadjuvant setting. However, in men with metastatic prostate cancer, 71% of the uro-oncologists measured testosterone before starting ADT and the majority continued testing during treatment. Approximately two-thirds of respondents did not prescribe TRT for their patients who were in remission following neo(adjuvant) ADT and who had castration levels of testosterone.

DISCUSSION

Among UK uro-oncologists, the measurement of testosterone levels before and during ADT was not typically part of routine practice in the management of patients with prostate cancer. However, testosterone levels were checked more frequently for patients with metastatic disease than disease at an earlier stage. Testing could be conducted in parallel with PSA measurement as testosterone levels are linked to biochemical failure. The majority of specialists participating in the survey did not prescribe TRT for their patients in remission following ADT.

CONCLUSION

Uro-oncologists in the UK do not generally measure testosterone as part of their patient management and they remain cautious about the possible benefits of TRT in men with prostate cancer.

Undetectable prostate-specific antigen after short-course androgen deprivation therapy for biochemically recurrent patients correlates with metastasis-free survival and prostate cancer-specific survival

BACKGROUND

Optimal utilization of novel therapies for advanced prostate cancer is challenging without a validated surrogate efficacy endpoint. Ongoing trials are using durable undetectable prostate-specific antigen (PSA) levels as a marker of efficacy. The clinical relevance of prolonged undetectable PSA after a short course of androgen deprivation therapy (ADT) is uncertain.

METHODS

The University of Washington Caisis database was queried for radical prostatectomy patients who received 6-12 months of ADT after biochemical recurrence (BCR), defined as PSA ≥0.2 ng/mL and no radiographically detectable metastasis. Proportions of men with undetectable PSA 12 and 24 months after ending ADT were compared to a hypothesized 5% rate using exact binomial tests. Associations with patient and tumor characteristics were examined using logistic regression, and associations with risk of subsequent metastasis and death were evaluated by log-rank tests.

RESULTS

After ineligibility exclusions, 23/93 (25%; 95%CI 16-35%; P < 0.001) and 14/93 (15%; 95%CI 9-24%; P < 0.001) had undetectable PSA 12 and 24 months after ending ADT, respectively. Detectable PSA at 12 months was associated with increased risk of metastasis (P = 0.006), prostate cancer-specific death (P = 0.028), and death from any cause (P = 0.065). Being 1 year older at diagnosis was associated with a 14% (95%CI 5-24%; P = 0.006) decrease in the odds of having a detectable PSA after controlling for PSA at diagnosis, PSA doubling time, grade group, and time from initial therapy to BCR.

CONCLUSIONS

This single-institution retrospective analysis shows that it is not uncommon to have undetectable PSA 12 or 24 months after a short course of ADT. No baseline prognostic characteristic other than age was associated with a durable (12 month) undetectable PSA. Because a durable undetectable PSA was associated with lower risks of metastasis and prostate cancer-specific death, it may be a reasonable clinical trial endpoint.

Prostate specific antigen (PSA) kinetic as a prognostic factor in metastatic prostate cancer receiving androgen deprivation therapy: systematic review and meta-analysis

Aim: Metastatic prostate cancer (mPCa) has a poor outcome with median survival of two to five years. The use of androgen deprivation therapy (ADT) is a gold standard in management of this stage.  Aim of this study is to analyze the prognostic value of PSA kinetics of patient treated with hormonal therapy related to survival from several published studies Method: Systematic review and meta-analysis was performed using literature searching in the electronic databases of MEDLINE, Science Direct, and Cochrane Library. Inclusion criteria were mPCa receiving ADT, a study analyzing Progression Free Survival (PFS), Overall Survival (OS), or Cancer Specific Survival (CSS) and prognostic factor of survival related to PSA kinetics (initial PSA, PSA nadir, and time to achieve nadir (TTN)). The exclusion criteria were metastatic castration resistant of prostate cancer (mCRPC) and non-metastatic disease. Generic inverse variance method was used to combine hazard ratio (HR) within the studies. Meta-analysis was performed using Review Manager 5.2 and a p-value <0.05 was considered statistically significant. Results: We found 873 citations throughout database searching with 17 studies were consistent with inclusion criteria. However, just 10 studies were analyzed in the quantitative analysis. Most of the studies had a good methodological quality based on Ottawa Scale. No significant association between initial PSA and PFS. In addition, there was no association between initial PSA and CSS/ OS. We found association of reduced PFS (HR 2.22; 95% CI 1.82 to 2.70) and OS/ CSS (HR 3.31; 95% CI 2.01-5.43) of patient with high PSA nadir. Shorter TTN was correlated with poor result of survival either PFS (HR 2.41; 95% CI 1.19 - 4.86) or CSS/ OS (HR 1.80; 95%CI  1.42 - 2.30) Conclusion: Initial PSA before starting ADT do not associated with survival in mPCa.  There is association of PSA nadir and TTN with survival.

Management Options for Biochemically Recurrent Prostate Cancer

Prostate cancer is the most common solid tumor malignancy in men worldwide. Treatment with surgery and radiation can be curative in organ-confined disease. Unfortunately, about one third of men develop biochemically recurrent disease based only on rising prostate-specific antigen (PSA) in the absence of visible disease on conventional imaging. For these patients with biochemical recurrent prostate cancer, there is no uniform guideline for subsequent management. Based on available data, it seems prudent that biochemical recurrent prostate cancer should initially be evaluated for salvage radiation or prostatectomy, with curative intent. In selected cases, high-intensity focused ultrasound and cryotherapy may be considered in patients that meet very narrow criteria as defined by non-randomized trials. If salvage options are not practical or unsuccessful, androgen deprivation therapy (ADT) is a standard option for disease control. While some patients prefer ADT to manage the disease immediately, others defer treatment because of the associated toxicity. In the absence of definitive randomized data, patients may be followed using PSA doubling time as a trigger to initiate ADT. Based on retrospective data, a PSA doubling time of less than 3-6 months has been associated with near-term development of metastasis and thus could be used signal to initiate ADT. Once treatment is begun, patients and their providers can choose between an intermittent and continuous ADT strategy. The intermittent approach may limit side effects but in patients with metastatic disease studies could not exclude a 20% greater risk of death. In men with biochemical recurrence, large studies have shown that intermittent therapy is non-inferior to continuous therapy, thus making this a reasonable option. Since biochemically recurrent prostate cancer is defined by technological limitations of radiographic detection, as new imaging (i.e., PSMA) strategies are developed, it may alter how the disease is monitored and perhaps managed. Furthermore, patients have no symptoms related to their disease and thus many prefer options that minimize toxicity. For this reason, herbal agents and immunotherapy are under investigation as potential alternatives to ADT and its accompanying side effects. New therapeutic options combined with improved imaging to evaluate the disease may markedly change how biochemically recurrent prostate cancer is managed in the future.

First off-time treatment prostate-specific antigen kinetics predicts survival in intermittent androgen deprivation for prostate cancer

BACKGROUND

Prostate-specific antigen (PSA) doubling time is relying on an exponential kinetic pattern. This pattern has never been validated in the setting of intermittent androgen deprivation (IAD). Objective is to analyze the prognostic significance for PCa of recurrent patterns in PSA kinetics in patients undergoing IAD.

METHODS

A retrospective study was conducted on 377 patients treated with IAD. On-treatment period (ONTP) consisted of gonadotropin-releasing hormone agonist injections combined with oral androgen receptor antagonist. Off-treatment period (OFTP) began when PSA was lower than 4 ng/ml. ONTP resumed when PSA was higher than 20 ng/ml. PSA values of each OFTP were fitted with three basic patterns: exponential (PSA(t) = λ.e(αt)), linear (PSA(t) = a.t), and power law (PSA(t) = a.t(c)). Univariate and multivariate Cox regression model analyzed predictive factors for oncologic outcomes.

RESULTS

Only 45% of the analyzed OFTPs were exponential. Linear and power law PSA kinetics represented 7.5% and 7.7%, respectively. Remaining fraction of analyzed OFTPs (40%) exhibited complex kinetics. Exponential PSA kinetics during the first OFTP was significantly associated with worse oncologic outcome. The estimated 10-year cancer-specific survival (CSS) was 46% for exponential versus 80% for nonexponential PSA kinetics patterns. The corresponding 10-year probability of castration-resistant prostate cancer (CRPC) was 69% and 31% for the two patterns, respectively. Limitations include retrospective design and mixed indications for IAD.

CONCLUSION

PSA kinetic fitted with exponential pattern in approximately half of the OFTPs. First OFTP exponential PSA kinetic was associated with a shorter time to CRPC and worse CSS.

Role of Hormonal Treatment in Prostate Cancer Patients with Nonmetastatic Disease Recurrence After Local Curative Treatment: A Systematic Review

CONTEXT

The relative benefits and harms of hormonal treatment (HT) versus no or deferred HT in patients with nonmetastatic prostate cancer (PCa) relapse after primary curative therapy are controversial.

OBJECTIVE

To assess the effectiveness of HT for nonmetastatic PCa relapse, prognostic factors for treatment outcome, timing of treatment, and the most effective treatment strategy to provide guidance for clinical practice.

EVIDENCE ACQUISITION

A systematic literature search was undertaken incorporating Medline, Embase, and the Cochrane Library (search ended March 2015). Studies were critically appraised for risk of bias. The outcomes included overall and cancer-specific survival, metastasis-free survival, symptom-free survival, progression to castrate resistance, adverse events, and quality of life.

EVIDENCE SYNTHESIS

Of 9687 articles identified, 27 studies were eligible for inclusion (2 RCTs, 8 nonrandomised comparative studies, and 17 case series). The results suggest that only a subgroup of patients, especially those with high-risk disease, may benefit from early HT. The main predictors for unfavourable outcomes were shorter PSA doubling time (<6-12 mo) and higher Gleason score (>7). Early HT may be warranted for patients with high-risk disease. An intermittent HT strategy appears feasible. Most studies had a moderate to high risks of bias.

CONCLUSIONS

HT for PCa relapse after primary therapy with curative intent should be reserved for patients at highest risk of progression and with a long life expectancy. The potential benefits of starting HT should be judiciously balanced against the associated harms.

PATIENT SUMMARY

This article summarises the evidence on the benefits and harms of hormonal treatment in prostate cancer (PCa) patients in whom the disease has recurred following earlier curative treatment. We found that only a select group of patients with aggressive PCa and a fast rising prostate-specific antigen may benefit from early hormonal treatment (HT), whereas in others HT may be more harmful than beneficial.

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.

Is intermittent androgen-deprivation therapy beneficial for patients with advanced prostate cancer?

Use of intermittent androgen-deprivation therapy (IADT) in patients with prostate cancer has been evaluated in several studies, in an attempt to delay the development of castration resistance and reduce side-effects associated with ADT. However it is still not clear whether survival is adversely affected in patients treated with IADT. In this review, we explore the available data in an attempt to identify the most suitable candidate patients for IADT, and discuss factors that may inform appropriate patient stratification. ADT is first-line treatment for advanced/metastatic prostate cancer and is also recommended for use with definitive radiotherapy for high-risk localised prostate cancer. The changes in hormone levels induced by ADT can lead to short- and long-term side-effects which, although treatable in most cases, can significantly reduce the tolerability of ADT treatment. IADT has been investigated in several phase II and phase III studies in patients with locally advanced or metastatic prostate cancer, in an attempt to delay time to tumour progression and reduce the side-effect burden of ADT. In selected patient groups IADT is no less effective than continuous ADT, ameliorating the impact of ADT-related side-effects, and, to a degree, their impact on patient health-related quality of life (HRQL). Further comparative study is required, particularly in relation to HRQL and long-term complications associated with ADT.

Management of patients with biochemical recurrence after local therapy for prostate cancer

Nearly three-quarters of a million American men who have been treated with prostatectomy and/or radiation therapy experience an increasing prostate-specific antigen level known as biochemical recurrence. Although androgen-deprivation therapy remains a reasonable option for some men with biochemical recurrence, deferring androgen ablation or offering nonhormonal therapies may be appropriate in patients in whom the risk of clinical or metastatic progression and prostate cancer-specific death is low. A risk-stratified approach informed by the patient's prostate-specific antigen kinetics, comorbidities, and personal preferences is recommended to determine the best management approach.

Androgen deprivation and high-dose radiotherapy for oligometastatic prostate cancer patients with less than five regional and/or distant metastases

BACKGROUND

Substantial survival may be observed with oligometastatic prostate cancer. Combining androgen deprivation (AD) and high-dose external beam radiotherapy (RT) to isolated regional or distant lesions may be proposed for these patients and the outcome of this strategy is the purpose of the present report.

MATERIAL AND METHODS

From 2003 to 2010, 50 prostate cancer patients were diagnosed with synchronous (n = 7) or metachronous (n = 43) oligometastases (OM). Among the relapsing patients, the recurrence occurred after radical prostatectomy in 33 patients and curative RT (± AD) in 10 patients. The median age at diagnosis was 63 years (range, 48-82). All patients underwent a bone scan and 18F-choline or 11C-acetate PET-CT at the time of diagnosis or relapse, showing regional and/or distant nodal and bone and/or visceral metastases in 33 and 17 patients, respectively. The median delivered effective dose was 64 Gy. All but one patient received neo-adjuvant and concomitant AD.

RESULTS

After a median follow-up of 31 months (range, 9-89) the three-year biochemical relapse-free survival (bRFS), clinical failure-free survival, and overall survival rates were 54.5%, 58.6% and 92%, respectively. No grade 3 toxicity was observed. Improved bRFS was found to be significantly associated with the number of OM. The three-year bRFS was 66.5% versus 36.4% for patients with 1 and > 1 OMs (p = 0.031). A normalised total dose (NTD in 2 Gy/fraction, alpha/beta = 2 Gy) above 64 Gy was also correlated with a better three-year bRFS compared to lower doses: 65% vs. 41.8%, respectively (p = 0.005). On multivariate analysis, only the NTD > 64 Gy retained statistical significance (HR: 0.37, 95% CI 0.15-0.93).

CONCLUSION

Oligometastatic patients may be successfully treated with short AD and high-dose irradiation to the metastatic lesions. High dose improves bRFS. Such a treatment strategy may hypothetically succeed to prolong the failure-free interval between two consecutive AD courses.

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.

Intermittent androgen-deprivation therapy in prostate cancer: a critical review focused on phase 3 trials

CONTEXT

Intermittent androgen deprivation (IAD) in prostate cancer (PCa) patients has been proposed to delay development of castration resistance and to reduce the side effects and costs of androgen deprivation therapy (ADT).

OBJECTIVE

This review analyzes (1) the oncologic and quality of life (QoL) results from randomized phase 3 trials comparing IAD and continuous ADT and (2) the prognostic parameters for IAD.

EVIDENCE ACQUISITION

We searched the Medline and Cochrane Library databases (primary fields: prostate neoplasm and intermittent androgen deprivation; secondary fields: randomized trials, survival, quality of life, predictors) without language restriction.

EVIDENCE SYNTHESIS

We found seven extensively described phase 3 trials randomizing 4675 patients to IAD versus continuous ADT. Other randomized trials investigating IAD have been performed, but available data are limited and have been published only in preliminary fashion. In all seven trials, patients spent most of their time on, rather than off, ADT. The induction periods ranged from 3 mo to 8 mo; in all but one trial, the PSA level designated for ADT discontinuation was <4 ng/ml. Mean follow-up ranged from 40-108 mo. Collectively, these trials support the concept that, mainly in metastatic cases, IAD can produce oncologic results similar to continuous ADT. In terms of overall survival, the hazard ratios for IAD and continuous ADT were very similar (range: 0.98-1.08). The QoL benefit of IAD appears to be modest at best. With IAD, QoL is likely influenced by the duration of the off-treatment periods and by the rate of testosterone recovery.

CONCLUSIONS

The evidence indicates that IAD is not inferior to continuous ADT. Data are insufficient to determine whether IAD is able to prevent the long-term complications of ADT. More comparative analysis focused on QoL is warranted.

Human prostate tumor antigen-specific CD8+ regulatory T cells are inhibited by CTLA-4 or IL-35 blockade

Regulatory T cells play important roles in cancer development and progression by limiting the generation of innate and adaptive anti-tumor immunity. We hypothesized that in addition to natural CD4(+)CD25(+) regulatory T cells (Tregs) and myeloid-derived suppressor cells, tumor Ag-specific Tregs interfere with the detection of anti-tumor immunity after immunotherapy. Using samples from prostate cancer patients immunized with a DNA vaccine encoding prostatic acid phosphatase (PAP) and a trans-vivo delayed-type hypersensitivity (tvDTH) assay, we found that the detection of PAP-specific effector responses after immunization was prevented by the activity of PAP-specific regulatory cells. These regulatory cells were CD8(+)CTLA-4(+), and their suppression was relieved by blockade of CTLA-4, but not IL-10 or TGF-β. Moreover, Ag-specific CD8(+) Tregs were detected prior to immunization in the absence of PAP-specific effector responses. These PAP-specific CD8(+)CTLA-4(+) suppressor T cells expressed IL-35, which was decreased after blockade of CTLA-4, and inhibition of either CTLA-4 or IL-35 reversed PAP-specific suppression of tvDTH response. PAP-specific CD8(+)CTLA-4(+) T cells also suppressed T cell proliferation in an IL-35-dependent, contact-independent fashion. Taken together, these findings suggest a novel population of CD8(+)CTLA-4(+) IL-35-secreting tumor Ag-specific Tregs arise spontaneously in some prostate cancer patients, persist during immunization, and can prevent the detection of Ag-specific effector responses by an IL-35-dependent mechanism.

The prognostic factors of effective ketoconazole treatment for metastatic castration-resistant prostate cancer: who can benefit from ketoconazole therapy?

We investigated the prognostic value of some variables of effective ketoconazole treatment for metastatic castration-resistant prostate cancer (mCRPC). In total, 163 patients with mCRPC were eligible, receiving ketoconazole 200-400 mg three times daily with replacement doses of prednisone. Progression-free survival (PFS) was calculated from the beginning of the ketoconazole therapy to the onset of disease progression. The prognostic value of different variables for PFS was assessed by Cox regression analysis. The median PFS was 2.6 months (0.5-8.6 months) for these patients. The serum testosterone level changed during therapy, which decreased when the prostate-specific antigen (PSA) declined; the serum testosterone level increased as the levels of PSA relapsed. The median PFS values for patients associated with different factors were the following: 1.4 and 3.5 months for a nadir PSA of ≥ 0.2 and <0.2 ng ml(-1), respectively (hazard rate (HR)=4.767, P<0.001); 3.1 and 1.6 months for a baseline testosterone of ≥ 0.1 and <0.1 ng ml(-1), respectively (HR=2.865, P=0.012); 2.8 and 1.9 months for a baseline haemoglobin of ≥ 120 and <120 g l(-1), respectively (HR=1.605, P<0.001); and 3.0 and 1.9 months for a PSA doubling time (PSADT) of ≥ 2.0 and <2.0 months, respectively (HR=1.454, P=0.017). A risk model was constructed according to the four factors that divided patients into three subgroups of low risk (0-1 factors), moderate risk (2 factors) and high risk (3-4 factors) with PFS values of 3.6, 3.0 and 1.4 months, respectively (HR=1.619, P<0.001). A nadir PSA of ≥ 0.2 ng ml(-1), a baseline testosterone of <0.1 ng ml(-1), a baseline haemoglobin of <120 g l(-1) and a PSADT of <2 months were associated with a poor PFS. This risk model could provide evidence to predict the survival benefit of ketoconazole therapy.

The FinnProstate Study VII: intermittent versus continuous androgen deprivation in patients with advanced prostate cancer

PURPOSE

We conducted a randomized trial to compare intermittent and continuous androgen deprivation in patients with advanced prostate cancer. We studied time to progression, overall and prostate cancer specific survival, and time to treatment failure.

MATERIALS AND METHODS

Between May 1997 and February 2003, 852 men with locally advanced or metastatic prostate cancer were enrolled to receive androgen deprivation therapy for 24 weeks. Patients in whom prostate specific antigen decreased to less than 10 ng/ml, or by 50% or more if less than 20 ng/ml at baseline, were randomized to intermittent or continuous androgen deprivation. In the intermittent therapy arm androgen deprivation therapy was withdrawn and resumed again for at least 24 weeks based mainly on prostate specific antigen decrease and increase.

RESULTS

There were 298 patients who did not meet the randomization criteria. The remaining 554 patients were randomized, with 274 (49.5%) to intermittent androgen deprivation and 280 (50.5%) to the continuous androgen deprivation arm. Median followup was 65.0 months. Of these patients 392 (71%) died, including 186 (68%) in the intermittent androgen deprivation arm and 206 (74%) in the continuous androgen deprivation arm (p=0.12). There were 248 prostate cancer deaths, comprised of 117 (43%) in the intermittent androgen deprivation and 131 (47%) in the continuous androgen deprivation arm (p=0.29). Median times from randomization to progression were 34.5 and 30.2 months in the intermittent androgen deprivation and continuous androgen deprivation arms, respectively. Median times to death (all cause) were 45.2 and 45.7 months, to prostate cancer death 45.2 and 44.3 months, and to treatment failure 29.9 and 30.5 months, respectively.

CONCLUSIONS

Intermittent androgen deprivation is a feasible, efficient and safe method to treat advanced prostate cancer compared with continuous androgen deprivation.

Changes in biomarkers of inflammation and angiogenesis during androgen deprivation therapy for prostate cancer

INTRODUCTION

Angiogenesis and inflammation are both important to the pathogenesis of malignancies. Androgen deprivation therapy (ADT) for prostate cancer causes drastic hormonal changes that alter both disease and host factors. We measured inflammatory and angiogenic biomarkers in ADT-treated and control groups of men with prostate cancer.

MATERIALS AND METHODS

Baseline and 12-week plasma samples were collected from 37 ADT-naïve men with locally advanced or recurrent prostate cancer. Of those, 23 initiated ADT with a gonadotropin-releasing hormone (GnRH) agonist and 14 served as nontreatment controls. Samples were tested for a panel of angiogenic and inflammatory biomarkers.

RESULTS

The treatment group had significantly higher concentrations of the inflammatory biomarkers interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, and stromal cell-derived factor (SDF)-1α. None of the angiogenic biomarkers were significantly different between the groups at baseline. Among patients with a short prostate-specific antigen (PSA) doubling time (<6 months), the proangiogenic factor basic fibroblast growth factor (bFGF) was lower at baseline. In the treatment group, plasma placental growth factor (PlGF) increased and IL-6 decreased after 12 weeks of ADT. Moreover, the treatment group continued to have significantly higher concentrations of the inflammatory biomarkers IL-1β, IL-8, and SDF-1α as well as bFGF than controls.

DISCUSSION

These men were characterized by elevations in several traditional markers of aggressive disease and also by higher levels of several inflammatory biomarkers. Although ADT decreased IL-6 levels, IL-1β, IL-8, and SDF-1α remained significantly higher than in controls. The role of these biomarkers should be further explored.