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Nanoparticle-based bio-barcode assay redefines "undetectable" PSA and biochemical recurrence after radical prostatectomy.

ABSTRACT: We report the development of a previously undescribed gold nanoparticle bio-barcode assay probe for the detection of prostate specific antigen (PSA) at 330 fg/mL, automation of the assay, and the results of a clinical pilot study designed to assess the ability of the assay to detect PSA in the serum of 18 men who have undergone radical prostatectomy for prostate cancer. Due to a lack of sensitivity, available PSA immunoassays are often not capable of detecting PSA in the serum of men after radical prostatectomy. This new bio-barcode PSA assay is approximately 300 times more sensitive than commercial immunoassays. Significantly, with the barcode assay, every patient in this cohort had a measurable serum PSA level after radical prostatectomy. Patients were separated into categories based on PSA levels as a function of time. One group of patients showed low levels of PSA with no significant increase with time and did not recur. Others showed, at some point postprostatectomy, rising PSA levels. The majority recurred. Therefore, this new ultrasensitive assay points to significant possible outcomes: (i) The ability to tell patients, who have undetectable PSA levels with conventional assays, but detectable and nonrising levels with the barcode assay, that their cancer will not recur. (ii) The ability to assign recurrence earlier because of the ability to measure increasing levels of PSA before conventional tools can make such assignments. (iii) The ability to use PSA levels that are not detectable with conventional assays to follow the response of patients to adjuvant or salvage therapies.

SUBMITTER: Thaxton CS

PROVIDER: S-EPMC2773980 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

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Nanoparticle-based bio-barcode assay redefines "undetectable" PSA and biochemical recurrence after radical prostatectomy.

Thaxton C Shad CS Elghanian Robert R Thomas Audrey D AD Stoeva Savka I SI Lee Jae-Seung JS Smith Norm D ND Schaeffer Anthony J AJ Klocker Helmut H Horninger Wolfgang W Bartsch Georg G Mirkin Chad A CA

Proceedings of the National Academy of Sciences of the United States of America 20091019 44

We report the development of a previously undescribed gold nanoparticle bio-barcode assay probe for the detection of prostate specific antigen (PSA) at 330 fg/mL, automation of the assay, and the results of a clinical pilot study designed to assess the ability of the assay to detect PSA in the serum of 18 men who have undergone radical prostatectomy for prostate cancer. Due to a lack of sensitivity, available PSA immunoassays are often not capable of detecting PSA in the serum of men after radic ...[more]

PMID: 19841273

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Project description:The objective of this study was to utilize a microarray platform to determine the microRNA (miRNA) expression profile in prostate cancer tissue from patients who underwent radical prostatectomy and were followed for an average of 47 months. The GeneChip® miRNA Array (Affymetrix) contains more than 46,000 probes, and more than 1,100 mature human miRNAs and transcripts. An expression level higher or lower than 1.1 with a p<0.05 were considered to be differentially expressed. When tumors with a GS<7 were compared with those with a GS≥7, five miRNAs were down-regulated and nine were up-regulated. In comparing tumors from patients with PSA <10 ng/mL vs. those with PSA ≥10 ng/mL, 21 miRNAs were down-regulated and 29 were overexpressed. There was decreased expression of 21 miRNAs and increased expression of 22 miRNAs when pT2 and pT3 tumors were compared. The comparison of the expression profiles of men with vs. without recurrent disease (PSA>0.2 ng/mL) revealed that 14 miRNAs were down-regulated and 17 were up-regulated. Considering the three prognostic factors and biochemical recurrence, miR-335 was overexpressed in pT3 tumors in patients with PSA>10 ng/mL, miR-1202 was overexpressed in recurrent tumors in which PSA >10 ng/mL, and miR-885 and miR-1226 were overexpressed in recurrent pT3 tumors. Six miRNAs (miR- 361, 378, 548, 574, 652 and 892) had decreased expression in pT3 tumors in patients with PSA >10 ng/mL. miR-16 was down-regulated in recurrent pT3 tumors. miR-92 and miR-450 exhibited decreased expression in recurrent tumors in patients with PSA > 10 ng/mL. miR-28 was down-regulated in pT3 adenocarcinomas with a GS ≥ 7. The differentially expressed miRNAs in recurrent tumors were validated using qRT-PCR in 74 additional specimens. miR-21 was overexpressed in recurrent tumors, and in the Cox model, expression levels higher than 0.64 were indicative of biochemical recurrence with a risk of 2.4. These results, which were based on clinical specimens from patients treated in a standardized way and followed for an average of 47 months, provide an initial understanding of the role of miRNAs in prostatecancer progression; the foremost representative is miR-21, which has been implicated in the progression of various human cancers.

Project description:The objective of this study was to utilize a microarray platform to determine the microRNA (miRNA) expression profile in prostate cancer tissue from patients who underwent radical prostatectomy and were followed for an average of 47 months. The GeneChipM-BM-. miRNA Array (Affymetrix) contains more than 46,000 probes, and more than 1,100 mature human miRNAs and transcripts. An expression level higher or lower than 1.1 with a p<0.05 were considered to be differentially expressed. When tumors with a GS<7 were compared with those with a GSM-bM-^IM-%7, five miRNAs were down-regulated and nine were up-regulated. In comparing tumors from patients with PSA <10 ng/mL vs. those with PSA M-bM-^IM-%10 ng/mL, 21 miRNAs were down-regulated and 29 were overexpressed. There was decreased expression of 21 miRNAs and increased expression of 22 miRNAs when pT2 and pT3 tumors were compared. The comparison of the expression profiles of men with vs. without recurrent disease (PSA>0.2 ng/mL) revealed that 14 miRNAs were down-regulated and 17 were up-regulated. Considering the three prognostic factors and biochemical recurrence, miR-335 was overexpressed in pT3 tumors in patients with PSA>10 ng/mL, miR-1202 was overexpressed in recurrent tumors in which PSA >10 ng/mL, and miR-885 and miR-1226 were overexpressed in recurrent pT3 tumors. Six miRNAs (miR- 361, 378, 548, 574, 652 and 892) had decreased expression in pT3 tumors in patients with PSA >10 ng/mL. miR-16 was down-regulated in recurrent pT3 tumors. miR-92 and miR-450 exhibited decreased expression in recurrent tumors in patients with PSA > 10 ng/mL. miR-28 was down-regulated in pT3 adenocarcinomas with a GS M-bM-^IM-% 7. The differentially expressed miRNAs in recurrent tumors were validated using qRT-PCR in 74 additional specimens. miR-21 was overexpressed in recurrent tumors, and in the Cox model, expression levels higher than 0.64 were indicative of biochemical recurrence with a risk of 2.4. These results, which were based on clinical specimens from patients treated in a standardized way and followed for an average of 47 months, provide an initial understanding of the role of miRNAs in prostatecancer progression; the foremost representative is miR-21, which has been implicated in the progression of various human cancers. Fifty-three patients underwent a radical prostatectomy performed by the same surgeon (MS) to treat localized PC between August 2000 and June 2002. The mean age was 65 years (SD: 7.5, range: 49 - 77). The mean Gleason score was 7 (SD: 1.1, range: 5 - 10); 15 tumors had a score of 5 or 6, and 38 had a score between 7 and 10. Twenty-four (45.3%) of the patients had pT2 tumors, and 29 (54.7%) had pT3 tumors. The control group consisted of three patients with lower urinary tract symptoms, a mean age of 55.3 years and a diagnosis of benign prostatic hyperplasia (BPH) who consented to open surgery.

Project description:Accurate estimation of recurrence risk is needed for optimal treatment of clinically localized prostate cancer (PCa) patients. We combined classical clinicopathological predictors of biochemical recurrence (BCR) and molecular markers into a new risk score for predicting BCR after radical prostatectomy (RP). A retrospective study which included 122 PCa patients who attended our department between 2000 and 2007 was conducted. Total RNA was isolated from formalin-fixed paraffin embedded PCa tissue. Gene expression patterns were analyzed in 21 selected samples from 7 localized, 6 locally advanced, and 8 metastatic PCa patients using Illumina microarrays. Expression levels of 41 genes were validated by quantitative PCR in an independent retrospective series of 101 patients with ≥ 10 years follow-up who underwent RP for clinically localized PCa. Univariate and multivariate logistic regression analysis were used to identify individual predictors of BCR. A risk score (RS) for predicting BCR including clinicopathological and gene expression data was developed and Kaplan-Meier curves were generated. Interaction networks between the genes of the model were built by GeneMANIA Cytoscape plugin. In a median follow-up of 120 months (range 3-190), 37 patients developed BCR (36.6%). Expression levels of 7,930 transcripts differed between clinically localized and locally advanced-metastatic PCa groups (FDR<0.1). A set of 41 genes were validated by quantitative PCR. Regression analysis showed that expression of ASF1B and MCL1 as well as Gleason score, extracapsular extension, seminal vesicle invasion and positive margins were independent prognostic factors of BCR. A RS generated using these gene expression and clinicopathological variables was able to discriminate between two groups of patients with a significantly different probability of BCR (HR 6.24; CI 3.23-12.4, p<0.01), improving the individual discriminative performance of each of these variables on their own. Direct interactions between the two genes of the model were not found. In conclusion, identification of new gene expression patterns associated with a high probability of BCR in clinically localized PCa patients treated with RP, and their combination with clinicopathological variables in a robust, easy-to-use and reliable classifier may contribute to improve PCa risk stratification and, consequently, to tailor treatment and surveillance strategies in these patients.

Project description:ObjectiveAlthough surveillance after radical prostatectomy routinely includes repeated prostate specific antigen (PSA)-testing for many years, biochemical recurrence often occurs without further clinical progression. We therefore hypothesised that follow-up can be shortened for many patients without increasing the risk of prostate cancer death. We investigated the long-term probabilities of PSA recurrence, metastases and prostate cancer death in patients without biochemical recurrence five and 10 years after radical prostatectomy.DesignProspective cohort study. Stratification by Gleason score (≤3+4=7 or ≥4+3=7), pathological tumour stage (pT2 or ≥pT3) and negative or positive surgical margins.SettingBetween 1989 and 1998, 14 urological centres in Scandinavia randomised patients to the Scandinavian Prostate Cancer Group study number 4 (SPCG-4) trial.ParticipationAll 306 patients from the SPCG-4 trial who underwent radical prostatectomy within 1 year from inclusion were eligible. Four patients were excluded due to surgery-related death (n=1) or salvage radiotherapy or hormonal treatment within 6 weeks from surgery (n=3).Primary outcome measuresCumulative incidences and absolute differences in metastatic disease and prostate cancer death.ResultsWe analysed 302 patients with complete follow-up during a median of 24 years. Median preoperative PSA was 9.8 ng/mL and median age was 65 years. For patients without biochemical recurrence 5 years after radical prostatectomy the 20-year probability of biochemical recurrence was 25% among men with Gleason score ≤3+4=7 and 57% among men with Gleason score ≥4+3=7; the probabilities for metastases were 0.8% and 17%; and for prostate cancer death 0.8% and 12%, respectively. The long-term probabilities were higher for pT ≥3 versus pT2 and for positive versus negative surgical margins. Limitations include small size of the cohort.ConclusionMany patients with favourable histopathology without biochemical recurrence 5 years after radical prostatectomy could stop follow-up earlier than 10 years after radical prostatectomy.

Project description:ImportanceStratifying patients with biochemical recurrence (BCR) after primary treatment for prostate cancer based on the risk of prostate cancer-specific mortality (PCSM) is essential for determining the need for further testing and treatments.ObjectiveTo evaluate the association of BCR after radical prostatectomy or radiotherapy and its current risk stratification with PCSM.Design, setting, and participantsThis population-based cohort study included a total of 16 311 male patients with 10 364 (64%) undergoing radical prostatectomy and 5947 (36%) undergoing radiotherapy with curative intent (cT1-3, cM0) and PSA follow-up in Stockholm, Sweden, between 2003 and 2019. Follow-up for all patients was until death, emigration, or end of the study (ie, December 31, 2018). Data were analyzed between September 2022 and March 2023.Main outcomes and measuresPrimary outcomes of the study were the cumulative incidence of BCR and PCSM. Patients with BCR were stratified in low- and high-risk according to European Association of Urology (EAU) criteria.ExposuresRadical prostatectomy or radiotherapy.ResultsA total of 16 311 patients were included. Median (IQR) age was 64 (59-68) years in the radical prostatectomy cohort (10 364 patients) and 69 (64-73) years in the radiotherapy cohort (5947 patients). Median (IQR) follow-up for survivors was 88 (55-138) months and 89 (53-134) months, respectively. Following radical prostatectomy, the 15-year cumulative incidences of BCR were 16% (95% CI, 15%-18%) for the 4024 patients in the low D'Amico risk group, 30% (95% CI, 27%-32%) for the 5239 patients in the intermediate D'Amico risk group, and 46% (95% CI, 42%-51%) for 1101 patients in the high D'Amico risk group. Following radiotherapy, the 15-year cumulative incidences of BCR were 18% (95% CI, 15%-21%) for the 1230 patients in the low-risk group, 24% (95% CI, 21%-26%) for the 2355 patients in the intermediate-risk group, and 36% (95% CI, 33%-39%) for the 2362 patients in the high-risk group. The 10-year cumulative incidences of PCSM after radical prostatectomy were 4% (95% CI, 2%-6%) for the 1101 patients who developed low-risk EAU-BCR and 9% (95% CI, 5%-13%) for 649 patients who developed high-risk EAU-BCR. After radiotherapy, the 10-year PCSM cumulative incidences were 24% (95% CI, 19%-29%) for the 591 patients in the low-risk EAU-BCR category and 46% (95% CI, 40%-51%) for the 600 patients in the high-risk EAU-BCR category.Conclusions and relevanceThese findings suggest the validity of EAU-BCR stratification system. However, while the risk of dying from prostate cancer in low-risk EAU-BCR after radical prostatectomy was very low, patients who developed low-risk EAU-BCR after radiotherapy had a nonnegligible risk of prostate cancer mortality. Improving risk stratification of patients with BCR is pivotal to guide salvage treatment decisions, reduce overtreatment, and limit the number of staging tests in the event of PSA elevations after primary treatment.

Project description:ObjectivesTo construct and externally calibrate a predictive model for early biochemical recurrence (BCR) after radical prostatectomy (RP) incorporating clinical and modern imaging characteristics of the primary tumour.Patients and methodsPatients who underwent RP following multiparametric magnetic resonance imaging, prostate biopsy and prostate-specific membrane antigen-positron emission tomography/computed tomography (PSMA-PET/CT), from two centres in Australia and the Netherlands. The primary outcome was biochemical recurrence-free survival (BRFS), where BCR was defined as a rising PSA level of ≥0.2 ng/mL or initiation of postoperative treatment per clinician discretion. Proportional hazards models to predict time to event were developed in the Australian sample using relevant pre- and post-surgical parameters and primary tumour maximum standardised uptake value (SUVmax) on diagnostic PSMA-PET/CT. Calibration was assessed in an external dataset from the Netherlands with the same inclusion criteria.ResultsData from 846 patients were used to develop the models. Tumour SUVmax was associated with worse predicted 3-year BRFS for both pre- and post-surgical models. SUVmax change from 4 to 16 lessened the predicted 3-year BRFS from 66% to 42% for a patient aged 65 years with typical pre-surgical parameters (PSA level 8 ng/mL, Prostate Imaging-Reporting and Data System score 4/5 and biopsy Gleason score ≥4 + 5). Considering post-surgical variables, a patient with the same age and PSA level but pathological stage pT3a, RP Gleason score ≥4 + 5 and negative margins, SUVmax change from 4 to 16 lessened the predicted 3-year BRFS from 76% to 61%. Calibration on an external sample (n = 464) showed reasonable performance; however, a tendency to overestimate survival in patients with good prognostic factors was observed.ConclusionTumour SUVmax on diagnostic PSMA-PET/CT has utility additional to commonly recognised variables for prediction of BRFS after RP.

Dataset Information

Nanoparticle-based bio-barcode assay redefines "undetectable" PSA and biochemical recurrence after radical prostatectomy.

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Nanoparticle-based bio-barcode assay redefines "undetectable" PSA and biochemical recurrence after radical prostatectomy.

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