Prostate specific antigen doubling time calculation: not as easy as 1, 2, 4

Non-metastatic castration-resistant prostate cancer: management recommendations

INTRODUCTION AND OBJECTIVE

Survival and quality of life (QoL) of patients with non-metastatic castration-resistant prostate cancer (nmCRPC) deteriorate significantly when they develop metastases. New generation antiandrogens (apalutamide, enzalutamide and darolutamide) can prolong metastasis-free survival (MFS) and overall survival (OS) in these patients, maintaining their QoL.

MATERIAL AND METHODS

After the performance of a systematic review of the literature, a scientific committee reached a consensus on simple and practical recommendations to consolidate and improve the management of patients with nmCRPC in urology consultations.

RESULTS

Recommendations are made on the frequency of PSA determination and imaging tests in patients with nmCRPC. The importance of co-morbidities in patients with nmCRPC is also highlighted, and recommendations are also made on functional and QoL assessment that can be carried out during urology consultations. The efficacy, safety, and effects on QoL of new generation antiandrogens are reviewed.

CONCLUSIONS

To evaluate treatment of patients with nmCRPC, it is necessary to consider co-morbidities and QoL, in addition to age. New generation antiandrogens are a safe and effective treatment option for patients with nmCRPC. The recommendations of this review can be helpful in optimizing the management of nmCRPC patients in urology consultations.

The role of thyroglobulin doubling time in differentiated thyroid cancer: a meta-analysis

OBJECTIVE

In patients with differentiated thyroid cancer (DTC), recurrences may occur in up to 20% and may have a fatal outcome in 10% of cases. Thyroglobulin doubling time (Tg-DT) values may contribute to predict response to treatment and disease recurrence in DTC patients. This study aimed to address the following questions: (1) Are Tg-DT values indicative of response to treatments in patients with DTC (i.e. 'treatment monitoring')?; (2) Is Tg-DT predictive of 2-[18F]fluoro-2-deoxy-d-glucose (2-[18F]FDG) PET/CT in patients with DTC?; (3) Are Tg-DT values predictive of DTC prognosis (i.e. 'prediction')?

DESIGN

Systematic review and meta-analysis.

METHODS

Methodology was registered in the PROSPERO database (CRD42021257947). A systematic search was carried out in PubMed, Web Of Science, and Scopus from June to August 2021 without time and language restrictions.

RESULTS

Eleven studies were included for a total of 1421 patients. Positive association between Tg-DT < 1 year and recurrence or disease progression was observed. Tg-DT was found to be related with (2-[18F]FDG) PET/CT results in patients with DTC. The area under the curve was 0.86 (95% CI: 0.83-0.89), sensitivity was 0.84 (0.64;0.94), specificity was 0.71 (0.35; 0.92), DOR was 13.1 (3.1; 55.0), LR+ was 2.9 (1.0; 8.1), LR- was 0.22 (0.1; 0.5). For patients with Tg-DT < 1 year (n = 247), the survival risk ratio was 2.09 (95% CI: 1.49; 2.94).

CONCLUSIONS

Tg-DT values are valuable in predicting response to treatment and disease recurrence in patients with DTC, as well as their overall survival. In addition, Tg-DT significantly increases the detection rate of 2-[18F]-FDG PET/CT.

The Calculus of Serum PSA

OBJECTIVES

To review the mathematics of kinetic changes in serum prostate-specific antigen (PSA) and to use a compartmental model to derive a new kinetic measure, alpha.

METHODS

The calculus of kinetic measures of PSA changes with time is presented, and a compartmental model is then used to derive alpha of serum PSA. Alpha is then tested for prognostic importance in 119 men who underwent prostatectomy.

RESULTS

The percentage of tumor in the prostate is closely related to alpha and to tumor length in diagnostic needle biopsies, but not to tumor grade. The presence of adverse pathology in the prostatectomy specimens (positive margins or T3 stage) is significantly associated with alpha, but not to tumor length or grade.

CONCLUSIONS

The derived kinetic parameter, alpha, shows promise as a preoperative prognostic parameter, and may help sort patients into those with low vs high probability for adverse pathology features in the prostatectomy specimens.

Prostate-specific antigen patterns in US and European populations: comparison of six diverse cohorts

OBJECTIVE

To determine whether there are differences in prostate-specific antigen (PSA) levels at diagnosis or changes in PSA levels between US and European populations of men with and without prostate cancer (PCa).

SUBJECTS AND METHODS

We analysed repeated measures of PSA from six clinically and geographically diverse cohorts of men: two cohorts with PSA-detected PCa, two cohorts with clinically detected PCa and two cohorts without PCa. Using multilevel models, average PSA at diagnosis and PSA change over time were compared among study populations.

RESULTS

The annual percentage PSA change of 4-5% was similar between men without cancer and men with PSA-detected cancer. PSA at diagnosis was 1.7 ng/mL lower in a US cohort of men with PSA-detected PCa (95% confidence interval 1.3-2.0 ng/mL), compared with a UK cohort of men with PSA-detected PCa, but there was no evidence of a different rate of PSA change between these populations.

CONCLUSION

We found that PSA changes over time are similar in UK and US men diagnosed through PSA testing and even in men without PCa. Further development of PSA models to monitor men on active surveillance should be undertaken in order to take advantage of these similarities. We found no evidence that guidelines for using PSA to monitor men cannot be passed between US and European studies.

Serum Thyroglobulin Doubling Time in Progressive Thyroid Cancer

BACKGROUND

Tumor marker doubling time (DT) has been proposed as a prognostic marker for various types of cancer. The present study analyzed the DT of the thyroid-specific tumor marker thyroglobulin (Tg), focusing on patients with progressive differentiated thyroid cancer (DTC).

METHODS

A total of 144 Tg courses of 99 patients with progressive or recurrent DTC were included (median observation period 19 months, 3-11 Tg measurements per course) in this retrospective study. The distribution of Tg-DT was determined for both a highly sensitive assay (functional working range 0.03-3 ng/mL) and a routine assay. Tg-DT and other prognostic markers were used to perform uni- and multivariate statistical analyses for survival predictors.

RESULTS

The median Tg-DT was 212 days (95% percentile: 49-961 days). No significant differences were observed between DT derived from Tg values in the very low range using a highly sensitive assay and DT calculated from Tg values measured by a conventional Tg assay. Multivariate analysis yielded no simple correlation between Tg-DT and survival rate, but the mortality risk of patients with a Tg-DT <5 months was more than twice as high as compared with a Tg-DT of >14 months. Highly significant differences on survival rates were only observed in patients with a high tumor load (Tg >100 ng/mL).

CONCLUSIONS

Tg-DT alone is not an independent survival predictor in all patients with progressive DTC; however, analyzing only patients with a high tumor load, we found highly significant differences in survival rates.

Development, validation and evaluation of an instrument for active monitoring of men with clinically localised prostate cancer: systematic review, cohort studies and qualitative study

Background

Active surveillance [(AS), sometimes called active monitoring (AM)],is a National Institute for Health and Care Excellence-recommended management option for men with clinically localised prostate cancer (PCa). It aims to target radical treatment only to those who would benefit most. Little consensus exists nationally or internationally about safe and effective protocols for AM/AS or triggers that indicate if or when men should move to radical treatment.

Objective

The aims of this project were to review how prostate-specific antigen (PSA) has been used in AM/AS programmes; to develop and test the validity of a new model for predicting future PSA levels; to develop an instrument, based on PSA, that would be acceptable and effective for men and clinicians to use in clinical practice; and to design a robust study to evaluate the cost-effectiveness of the instrument.

Methods

A systematic review was conducted to investigate how PSA is currently used to monitor men in worldwide AM/AS studies. A model for PSA change with age was developed using Prostate testing for cancer and Treatment (ProtecT) data and validated using data from two PSA-era cohorts and two pre-PSA-era cohorts. The model was used to derive 95% PSA reference ranges (PSARRs) across ages. These reference ranges were used to predict the onset of metastases or death from PCa in one of the pre-PSA-era cohorts. PSARRs were incorporated into an active monitoring system (AMS) and demonstrated to 18 clinicians and 20 men with PCa from four NHS trusts. Qualitative interviews investigated patients’ and clinicians’ views about current AM/AS protocols and the acceptability of the AMS within current practice.

Results

The systematic review found that the most commonly used triggers for clinical review of PCa were PSA doubling time (PSADT) < 3 years or PSA velocity (PSAv) > 1 ng/ml/year. The model for PSA change (developed using ProtecT study data) predicted PSA values in AM/AS cohorts within 2 ng/ml of observed PSA in up to 79% of men. Comparing the three PSA markers, there was no clear optimal approach to alerting men to worsening cancer. The PSARR and PSADT markers improved the modelc-statistic for predicting death from PCa by 0.11 (21%) and 0.13 (25%), respectively, compared with using diagnostic information alone [PSA, age, tumour stage (T-stage)]. Interviews revealed variation in clinical practice regarding eligibility and follow-up protocols. Patients and clinicians perceive current AM/AS practice to be framed by uncertainty, ranging from uncertainty about selection of eligible AM/AS candidates to uncertainty about optimum follow-up protocols and thresholds for clinical review/radical treatment. Patients and clinicians generally responded positively to the AMS. The impact of the AMS on clinicians’ decision-making was limited by a lack of data linking AMS values to long-term outcomes and by current clinical practice, which viewed PSA measures as one of several tools guiding clinical decisions in AM/AS. Patients reported that they would look to clinicians, rather than to a tool, to direct decision-making.

Limitations

The quantitative findings were severely hampered by a lack of clinical outcomes or events (such as metastases). The qualitative findings were limited through reliance on participants’ reports of practices and recollections of events rather than observations of actual interactions.

Conclusions

Patients and clinicians found that the instrument provided additional, potentially helpful, information but were uncertain about the current usefulness of the risk model we developed for routine management. Comparison of the model with other monitoring strategies will require clinical outcomes from ongoing AM/AS studies.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Exponential rise in prostate-specific antigen (PSA) during anti-androgen withdrawal predicts PSA flare after docetaxel chemotherapy in patients with castration-resistant prostate cancer

PURPOSE

To investigate the relationship between rising patterns of prostate-specific antigen (PSA) before chemotherapy and PSA flare during the early phase of chemotherapy in patients with castration-resistant prostate cancer (CRPC).

MATERIALS AND METHODS

This study included 55 patients with CRPC who received chemotherapy and in whom pre-treatment or post-treatment PSA levels could be serially obtained. The baseline parameters included age, performance, Gleason score, PSA level, and disease extent. PSA doubling time was calculated using the different intervals: the conventional interval from the second hormone manipulation following the nadir until anti-androgen withdrawal (PSADT1), the interval from the initial rise after anti-androgen withdrawal to the start of chemotherapy (PSADT2), and the interval from the nadir until the start of chemotherapy (PSADT3). The PSA growth patterns were analyzed using the ratio of PSADT2 to PSADT1.

RESULTS

There were two growth patterns of PSA doubling time: 22 patients (40.0%) had a steady pattern with a more prolonged PSADT2 than PSADT1, while 33 (60.0%) had an accelerating pattern with a shorter PSADT2 than PSADT1. During three cycles of chemotherapy, PSA flare occurred in 11 patients (20.0%); of these patients, 3 were among 33 (9.1%) patients with an accelerating PSA growth pattern and 8 were among 22 patients (36.4%) with a steady PSA growth pattern (p=0.019). Multivariate analysis showed that only PSA growth pattern was an independent predictor of PSA flare (p=0.034).

CONCLUSION

An exponential rise in PSA during anti-androgen withdrawal is a significant predictor for PSA flare during chemotherapy in CRPC patients.

Curated microRNAs in urine and blood fail to validate as predictive biomarkers for high-risk prostate cancer

Purpose

The purpose of this study was to determine if microRNA profiling of urine and plasma at radical prostatectomy can distinguish potentially lethal from indolent prostate cancer.

Materials and Methods

A panel of microRNAs was profiled in the plasma of 70 patients and the urine of 33 patients collected prior to radical prostatectomy. Expression of microRNAs was correlated to the clinical endpoints at a follow-up time of 3.9 years to identify microRNAs that may predict clinical response after radical prostatectomy. A machine learning approach was applied to test the predictive ability of all microRNAs profiled in urine, plasma, and a combination of both, and global performance assessed using the area under the receiver operator characteristic curve (AUC). Validation of urinary expression of miRNAs was performed on a further independent cohort of 36 patients.

Results

The best predictor in plasma using eight miRs yielded only moderate predictive performance (AUC = 0.62). The best predictor of high-risk disease was achieved using miR-16, miR-21 and miR-222 measured in urine (AUC = 0.75). This combination of three microRNAs in urine was a better predictor of high-risk disease than any individual microRNA. Using a different methodology we found that this set of miRNAs was unable to predict high-volume, high-grade disease.

Conclusions

Our initial findings suggested that plasma and urinary profiling of microRNAs at radical prostatectomy may allow prognostication of prostate cancer behaviour. However we found that the microRNA expression signature failed to validate in an independent cohort of patients using a different platform for PCR. This highlights the need for independent validation patient cohorts and suggests that urinary microRNA signatures at radical prostatectomy may not be a robust way to predict the course of clinical disease after definitive treatment for prostate cancer.

Clinical characteristics and prostate-specific antigen kinetics of prostate cancer detected in repeat annual population screening in Japan

OBJECTIVES

To clarify the present status regarding repeat examination in the annual population screening system in Japan, and to analyze the clinical characteristics and prostate-specific antigen kinetics of prostate cancer detected in this setting.

METHODS

We summarized the annual individual data of prostate-specific antigen-based population screening in Kanazawa, Japan, and analyzed the prostate cancer detection rates at first and repeat screening. The clinical characteristics were compared between patients detected at first and repeat screening. The patients were classified according to favorable or unfavorable clinical characteristics of cancer, and prostate-specific antigen kinetics were compared between the two groups.

RESULTS

From 2000 to 2011, 19 620 men participated in this screening program, and a total of 59 019 screenings were carried out. The total annual numbers of examinees increased, and the annual rates of first examinees gradually decreased. The annual detection rates of cancer at total screening decreased in the second year. The annual detection rate at first screening was not different from that in the first year. The rate of patients with favorable cancer features was significantly higher among patients detected at repeat screening than at first screening. The rates of patients with high prostate-specific antigen velocity and low prostate-specific antigen doubling time were significantly higher in unfavorable than favorable cancer patients in repeat screening.

CONCLUSIONS

Repeat population screening could contribute to early detection of prostate cancer, and it seems that prostate-specific antigen kinetics might predict the cancer characteristics in repeat screening.

An examination of the dynamic changes in prostate-specific antigen occurring in a population-based cohort of men over time

OBJECTIVE

• To determine whether prostate-specific antigen velocity (PSA-V), PSA doubling time (PSA-DT), or PSA percentage change (PSA-PC) add incremental information to PSA alone for community-based men undergoing prostate cancer (PCa) screening.

PARTICIPANTS AND METHODS

• A population-based cohort of 11 872 men from Olmsted County, MN undergoing PSA screening for PCa from 1993 to 2005 was analysed for PSA, PSA-DT, PSA-PC and PSA-V and subsequent PCa. • Receiver-operating characteristics curves and logistic regression were used to calculate the area under the curve (AUC) and Aikaike's information criterion. • Reclassification analysis was performed and the net reclassification improvement and integrated discrimination improvement were measured. • The method of Begg and Greenes was used to adjust for verification bias.

RESULTS

• The single best predictor of future PCa was PSA (AUC = 0.773) with PSA-V (AUC = 0.729) and PSA-DT/PSA-PC (AUC = 0.689) performing worse. • After age adjustment, combining PSA with PSA-V (AUC = 0.773) or PSA-DT/PSA-PC (AUC = 0.773) resulted in no better predictions than PSA alone. • Reclassification analysis showed that adding PSA-V or PSA-DT/PSA-PC to PSA did not result in a meaningful amount of reclassification.

CONCLUSIONS

• PSA is a better predictor of future PCa than PSA-V, PSA-DT, or PSA-PC. • Adding PSA-V, PSA-DT, or PSA-PC to PSA does not result in clinically relevant improvements in the ability to predict future PCa.

Active surveillance in prostate cancer: patient selection and triggers for intervention

PURPOSE OF REVIEW

The long-term safety and effectiveness of active surveillance depends on our ability to select appropriate patients and trigger delayed treatment in those who need it, whereas avoiding intervention in those who do not. In this review, we will consider how recent advances have influenced patient selection for active surveillance and review the range of different intervention triggers that have been proposed.

RECENT FINDINGS

Several large surveillance cohort studies have been reported recently showing excellent medium-term outcomes in well selected patients, with approximately a third of patients going on to have deferred treatment. Debate continues on the most appropriate eligibility criteria for active surveillance and what triggers for intervention should be used. There is growing interest in the role of transperineal template biopsies and multiparametric MRI, both for patient selection and in identifying triggers for intervention.

SUMMARY

Active surveillance is a well tolerated treatment option in well selected groups of patients. There is no 'one size fits all' set of criteria for patient selection or triggers for intervention but decisions can be guided by information from histology, prostate-specific antigen kinetics and imaging.

Impact of neoadjuvant prostate-specific antigen kinetics on biochemical failure and prostate cancer mortality: results from a prospective patient database

PURPOSE

To confirm findings from an earlier report showing that neoadjuvant (NA) prostate-specific antigen (PSA) halving time (PSAHT) impacts biochemical failure (BF) rates, and to examine its association with prostate cancer-specific survival (PCSS), in a large prospective cohort of patients.

METHODS AND MATERIALS

A total of 502 patients were selected from a prospective database, who had localized prostate adenocarcinoma treated with 2-12 months of neoadjuvant androgen deprivation therapy (N-ADT) followed by external beam radiation therapy (EBRT) between 1994 and 2000, and had at least 2 NA PSA values. Seventy-four percent of patients had high-risk prostate cancer. Median initial PSA value, N-ADT duration, total ADT duration, and radiation therapy dose were 14 ng/mL, 6.9 months, 10.8 months, and 68 Gy, respectively.

RESULTS

At a median follow-up of 9.9 years, 210 patients have had a BF. Median PSAHT was 18 days. On univariate analysis, PSAHT was not shown to predict for BF (P=.69) or PCSS (P=.28). However, NA nadir PSA (nanPSA) and post-therapy nadir PSA (ptnPSA), when analyzed as continuous or categoric variables, predicted for BF (P<.001) and PCSS (P<.001). On multivariate analysis, nanPSA (P=.037) and ptnPSA (P<.001) continued to be significantly associated with BF. However, N-ADT duration lost significance (P=.67), and PSAHT remained a nonsignificant predictor (P=.97). For PCSS, multivariate analysis showed nanPSA (P=.049) and ptnPSA (P<.001) to be significant. Again PSAHT (P=.49) remained nonsignificant.

CONCLUSIONS

In this large, prospective cohort of patients, NA PSA kinetics, expressed as PSAHT, did not predict BF or PCSS. However, nadir PSAs, in both the NA and post-therapy settings, were significant predictors of BF and PCSS. Optimization of therapy could potentially be based on early PSA response, with shorter durations of ADT for those predicted to do favorably, and intensification of therapy for those likely to have poorer outcomes.

Impact of pathological tumor stage for salvage radiotherapy after radical prostatectomy in patients with prostate-specific antigen < 1.0 ng/ml

BACKGROUND

To evaluate prognostic factors in salvage radiotherapy (RT) for patients with pre-RT prostate-specific antigen (PSA) < 1.0 ng/ml.

METHODS

Between January 2000 and December 2009, 102 patients underwent salvage RT for biochemical failure after radical prostatectomy (RP). Re-failure of PSA after salvage RT was defined as a serum PSA value of 0.2 ng/ml or more above the postradiotherapy nadir followed by another higher value, a continued rise in serum PSA despite salvage RT, or initiation of systemic therapy after completion of salvage RT. Biochemical relapse-free survival (bRFS) was estimated using the Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards regression model.

RESULTS

The median follow-up period was 44 months (range, 11-103 months). Forty-three patients experienced PSA re-failure after salvage RT. The 4-year bRFS was 50.9% (95% confidence interval [95% CI]: 39.4-62.5%). In the log-rank test, pT3-4 (p < 0.001) and preoperative PSA (p = 0.037) were selected as significant factors. In multivariate analysis, only pT3-4 was a prognostic factor (hazard ratio: 3.512 [95% CI: 1.535-8.037], p = 0.001). The 4-year bRFS rates for pT1-2 and pT3-4 were 79.2% (95% CI: 66.0-92.3%) and 31.7% (95% CI: 17.0-46.4%), respectively.

CONCLUSIONS

In patients who have received salvage RT after RP with PSA < 1.0 ng/ml, pT stage and preoperative PSA were prognostic factors of bRFS. In particular, pT3-4 had a high risk for biochemical recurrence after salvage RT.

Evaluation of prediagnostic prostate-specific antigen dynamics as predictors of death from prostate cancer in patients treated conservatively

Prostate-specific antigen (PSA) dynamics have been proposed to predict outcome in men with prostate cancer. We assessed the value of PSA velocity (PSAV) and PSA doubling time (PSADT) for predicting prostate cancer-specific mortality (PCSM) in men with clinically localized prostate cancer undergoing conservative management or early hormonal therapy. From 1990 to 1996, 2,333 patients were identified, of whom 594 had two or more PSA values before diagnosis. We examined 12 definitions for PSADT and 10 for PSAV. Because each definition required PSA measurements at particular intervals, the number of patients eligible for each definition varied from 40 to 594 and number of events from 10 to 119. Four PSAV definitions, but no PSADT, were significantly associated with PCSM after adjustment for PSA in multivariable Cox proportional hazards regression. All four could be calculated only for a proportion of events, and the enhancements in predictive accuracy associated with PSAV had very wide confidence intervals. There was no clear benefit of PSAV in men with low PSA and Gleason grade 6 or less. Although evidence that certain PSAV definitions help to predict PCSM in the cohort exist, the value of incorporating PSAV in predictive models to assist in determining eligibility for conservative management is, at best, uncertain.

Predicting biopsy-proven prostate cancer recurrence following cryosurgery

OBJECTIVES

Prostate cancer (CaP) cryosurgery utilizes PSA nadir level and radiotherapy criteria as surrogates for success. We attempted to correlate PSA doubling time (PSAdt) and time of undetectable PSA (TUPSA) with biopsy-proven cancer recurrence (BPR) in men treated with primary third-generation cryotherapy for clinically localized CaP.

MATERIALS AND METHODS

Demographic, clinical, and pathologic data was retrieved including age, race, use of preoperative hormones or 5-α reductase inhibitors (5-ARIs), initial biopsy PSA, biopsy Gleason score, cT stage, prostate volume, presence/absence median lobe, and follow-up. Post-cryotherapy biopsy was considered for PSA levels ≥ 0.5 ng/ml. PSAdt was determined by the log-slope method. TUPSA was defined as time from surgery to a PSA value ≥ 0.2 ng/ml or most recent follow-up if undetectable.

RESULTS

Ninety-seven patients were identified. Preoperative hormonal manipulation was used in 25 (26%); 5 (5%) were using a 5-ARI. Twenty-seven (29%) underwent post-cryotherapy biopsy, 12 (12%) had a BPR. In 41 (42%), PSAdt was calculated (median 11.9 months, IQR 6.6-34.8); no significant difference between patients with BPR and without CaP was found (P = 0.46). TUPSA was a median of 4.9 months (IQR 3.2-9.9) vs. 15.6 months (IQR 6.1-30.3) for BPR or no CaP, respectively (P = 0.005). On proportional hazards regression, TUPSA was the only independent predictor of BPR (P = 0.03, OR 0.91).

CONCLUSIONS

Post-cryosurgery PSAdt does not appear to be associated with BPR risk, whereas TUPSA reduces the risk of BPR by 9% per month. This may help guide management if local failure is suspected.

Open-label, phase I dose-escalation study of sodium selenate, a novel activator of PP2A, in patients with castration-resistant prostate cancer

Background:

Angiogenesis is fundamental to the progression of many solid tumours including prostate cancer. Sodium selenate is a small, water-soluble, orally bioavailable activator of PP2A phosphatase with anti-angiogenic properties.

Methods:

This was a dose-escalation phase I study in men with asymptomatic, chemotherapy-naïve, castration-resistant prostate cancer. The primary objective was to determine the maximum tolerated dose (MTD). Secondary objectives included establishing the safety, tolerability and pharmacokinetic profile.

Results:

A total of 19 patients were enrolled. The MTD was 60 mg per day. Dose-limiting toxicity (fatigue and diarrhoea) was observed at 90 mg per day. The most frequently reported treatment-related adverse events across all treatment cohorts were nausea, diarrhoea, fatigue, muscle spasms, alopecia and nail disorders. No grade 4 toxicities were observed and there were no deaths on study. Linear pharmacokinetics was observed. One patient had a PSA response >50%. Median time to PSA progression (for non-responders) was 14.2 weeks. Mean PSA doubling time increased during the main treatment phase from 2.18 months before trial to 3.85 months.

Conclusion:

Sodium selenate is well tolerated at a dose of 60 mg per day with modest single-agent efficacy similar to other anti-angiogenic agents. Further trials in combination with conventional cytotoxic regimens are warranted.

A phase II trial of a soy beverage for subjects without clinical disease with rising prostate-specific antigen after radical radiation for prostate cancer

Our objective was to evaluate the tolerability and effect of a daily soy beverage in prostate cancer patients with biochemical failure after radiotherapy. Patients with rising prostate-specific antigen (PSA) after radical radiation for prostate cancer were instructed to consume 500 ml of soy beverage daily for 6 mo. Tolerability of the soy beverage and compliance were assessed. PSA doubling times before and after the consumption of soy were compared. Thirty-four subjects were enrolled; 5 withdrew before 1 mo of soy for reasons unrelated to soy consumption. All remaining 29 subjects were included in the analysis. Mean consumption of the assigned soy beverage was 93%. Mild gastrointestinal upset (38%) not affecting soy consumption was the commonest side effect. PSA showed a declining trend in 4 patients (13.8%), and there was a > 100% prolongation of PSA doubling time in 8 patients (27.6%). However, PSA doubling time also showed a 50% or more shortening in 5 patients (17.2%). In our cohort of North American subjects, 6 mo of a daily soy beverage was well tolerated and was associated with a declining trend or more than 2 times prolongation of PSA doubling time in 41% of subjects. Confirmatory studies are warranted.

Open-label, clinical phase I studies of tasquinimod in patients with castration-resistant prostate cancer

Background:

Tasquinimod is a quinoline-3-carboxamide derivative with anti-angiogenic activity. Two open-label phase I clinical trials in patients were conducted to evaluate the safety and tolerability of tasquinimod, with additional pharmacokinetic and efficacy assessments.

Methods:

Patients with castration-resistant prostate cancer with no previous chemotherapy were enrolled in this study. The patients received tasquinimod up to 1 year either at fixed doses of 0.5 or 1.0 mg per day or at an initial dose of 0.25 mg per day that escalated to 1.0 mg per day.

Results:

A total of 32 patients were enrolled; 21 patients were maintained for ⩾4 months. The maximum tolerated dose was determined to be 0.5 mg per day; but when using stepwise intra-patient dose escalation, a dose of 1.0 mg per day was well tolerated. The dose-limiting toxicity was sinus tachycardia and asymptomatic elevation in amylase. Common treatment-emergent adverse events included transient laboratory abnormalities, anaemia, nausea, fatigue, myalgia and pain. A serum prostate-specific antigen (PSA) decline of ⩾50% was noted in two patients. The median time to PSA progression (>25%) was 19 weeks. Only 3 out of 15 patients (median time on study: 34 weeks) developed new bone lesions.

Conclusion:

Long-term continuous oral administration of tasquinimod seems to be safe, and the overall efficacy results indicate that tasquinimod might delay disease progression.

Pretreatment prostate-specific antigen (PSA) velocity and doubling time are associated with outcome but neither improves prediction of outcome beyond pretreatment PSA alone in patients treated with radical prostatectomy

PURPOSE

Controversy exists as to whether current pretreatment prostate-specific antigen (PSA) dynamics enhance outcome prediction in patients undergoing treatment for prostate cancer. We assessed whether pretreatment PSA velocity (PSAV) or doubling time (PSADT) predicted outcome in men undergoing radical prostatectomy and whether any definition enhanced accuracy of an outcome prediction model.

PATIENTS AND METHODS

The cohort included 2,938 patients with two or more PSA values before radical prostatectomy. Biochemical recurrence (BCR) occurred in 384 patients, and metastases occurred in 63 patients. Median follow-up for patients without BCR was 2.1 years. We used univariate Cox proportional hazards regression to evaluate associations between published definitions of PSADT and PSAV with BCR and metastasis. Predictive accuracy was assessed using the concordance index.

RESULTS

On univariate analysis, two of 12 PSADT and four of 10 PSAV definitions were univariately associated with both BCR and metastasis (P < .05). One PSADT and one PSAV definition had a higher predictive accuracy for BCR over PSA alone, and four PSAV definitions improved prediction of metastasis. However, the improvements in predictive accuracy were small, associated with wide CIs, and markedly reduced if additional predictors of stage and grade were included alongside PSA. Modeling with random variables suggests that similar results would be expected by chance. CONCLUSION We found no clear evidence that any definition of PSA dynamics substantially enhances the predictive accuracy of a single pretreatment PSA alone.

Diet and dietary supplement intervention trials for the prevention of prostate cancer recurrence: a review of the randomized controlled trial evidence

PURPOSE

We review the effect of diet and dietary supplement interventions on prostate cancer progression, recurrence and survival.

MATERIALS AND METHODS

A literature search was conducted in MEDLINE, EMBASE and CINAHL to identify diet and dietary supplement intervention studies in men with prostate cancer using prostate specific antigen or prostate specific antigen doubling time as a surrogate serum biomarker of prostate cancer recurrence and/or survival.

RESULTS

Of the 32 studies identified 9 (28%) were randomized controlled trials and the focus of this review. In these studies men had confirmed prostate cancer and elevated or increasing prostate specific antigen. Only 1 trial included men with metastatic disease. When body mass index was reported, men were overweight or obese. A significant decrease in prostate specific antigen was observed in some studies using a low fat vegan diet, soy beverage or lycopene supplement. While not often reported as an end point, a significant increase in prostate specific antigen doubling time was observed in a study on lycopene supplementation. In only 1 randomized controlled trial in men undergoing orchiectomy was a survival end point of fewer deaths with lycopene supplementation reported.

CONCLUSIONS

A limited number of randomized controlled trials were identified in which diet and dietary supplement interventions appeared to slow disease progression in men with prostate cancer, although results vary. Studies were limited by reliance on the surrogate biomarker prostate specific antigen, sample size and study duration. Well designed trials are warranted to expand knowledge, replicate findings and further assess the impact of diet and dietary supplement interventions on recurrence and treatment associated morbidities.

Prostate-specific antigen (PSA) kinetics in untreated, localized prostate cancer: PSA velocity vs PSA doubling time

OBJECTIVES

To compare the accuracy of prostate-specific antigen (PSA) velocity (PSAV) vs PSA doubling time (DT) for predicting the repeat biopsy results in men with localized prostate cancer on active surveillance (AS), as the utility of PSAV vs PSADT in untreated prostate cancer has not been well studied.

PATIENTS AND METHODS

Eligible patients had favourable-risk localized prostate cancer (T1/2a, PSA level <or=15 ng/mL, Gleason score <or=3 + 4, and percentage positive biopsy cores <or=50%), and consented to AS between 2002 and 2005. Repeat biopsies were taken after 18-24 months, with adverse histology defined as any of: primary Gleason grade >or=4, >50% cores positive, or initial Gleason score 3 + 3 upgraded to >or=3 + 4. Using all PSA values for the 2 years preceding repeat biopsy, the PSAV and PSADT were calculated using linear regression and the log-slope method (DT = ln2/slope), respectively.

RESULTS

In all, 199 patients were assessable; the median PSAV and PSADT were 0.71 ng/mL/year and 5.29 years, respectively. Fifty-three patients (27%) had adverse histology on repeat biopsy. On univariate analyses, PSAV (P < 0.001) and PSADT (P = 0.019) were associated with adverse histology. The area under the receiver operating characteristic curve for predicting adverse histology was 0.70 and 0.63 for PSAV and PSADT, respectively. The mean difference was 0.07 (95% confidence interval 0.03-0.12; P < 0.001).

CONCLUSIONS

PSAV is more accurate than PSADT for predicting adverse histology on repeat biopsies. These data suggest that PSAV should be used in preference to PSADT to describe PSA kinetics in untreated, localized prostate cancer.

Progression after docetaxel-based chemotherapy in androgen-independent prostate cancer

OBJECTIVE

To assess the clinical pattern of progression and prostate-specific antigen doubling time (PSA-DT) after exposure to docetaxel-based chemotherapy in patients with androgen-independent prostate cancer (AIPC).

PATIENTS AND METHODS

Fifty-five patients received docetaxel-based chemotherapy; data were collected retrospectively from three different departments. Progression was known in 44 (79%) and the PSA-DT was available in 33 patients.

RESULTS

Of the 29 patients with soft-tissue and soft-tissue plus bone metastases, 22 (76%) developed soft-tissue progression. Among the 35 patients with bone and bone plus soft-tissue metastases, 27 (77%) had osseous progression. There was no difference between the PSA-DT at progression before and after docetaxel-based therapy (mean 3.1 vs 2.7 months, P = 0.592, Student's t-test.). However, the median (range) PSA-DT at progression after docetaxel-based therapy was 0.84 (0.3-4) months in patients with a PSA response, significantly shorter than the median of 3.1 (0.3-12) months of patients with no biochemical response (P = 0.002, Student's t-test). The PSA-DT dynamics at progression had no effect on survival (P = 0.63, log-rank test).

CONCLUSION

The pattern of progression after docetaxel-based chemotherapy is predominantly osseous in patient with bone metastases and mostly soft-tissue in those with soft-tissue disease. Progression after docetaxel-based chemotherapy in AIPC does not modify the PSA-DT before docetaxel. Evaluation of a larger population is needed to assess the clinical relevance of PSA dynamics after docetaxel therapy.