Biochemical recurrence after radical prostatectomy according to nadir prostate specific antigen value.

The hypersensitive prostate specific antigen (PSA) test can measure in 0.01 ng/mL units, and its efficacy for screening after radical prostatectomy (RP) has been reported. In this study, we assessed patients who underwent RP to evaluate whether the nadir value affects biochemical recurrence (BCR). From 1995 to 2014, patients classified as N0 who had negative resection margins and a nadir PSA of less than 0.2 ng/mL were evaluated. The characteristics, pathological outcomes, PSA after RP, and BCR were assessed. A total of 1483 patients were enrolled. Among them, 323 (21.78%) patients showed BCR after RP. The mean age of the BCR group was 63.86±7.31 years, and while that of the no-recurrence group was 64.06±6.82 years (P = 0.645). The mean preoperative PSA of the BCR group was 9.75±6.92 ng/mL and that of the no-recurrence group was 6.71±5.19 ng/mL (P < 0.001). The mean time to nadir (TTN) in the BCR group was 4.64±7.65 months, while that in the no-recurrence group was 7.43±12.46 months (P < 0.001). The mean PSA nadir value was 0.035±0.034 ng/mL in the BCR group and 0.014±0.009 ng/mL in the no-recurrence group (P < 0.001). In multivariable Cox regression analyses, Gleason score, positive biopsy core percentages, minimal invasive surgery, nadir PSA value, and TTN were independently associated with BCR. The mean BCR occurred at 48.23±2.01 months after RP, and there was a significant difference in BCR occurrence according to the nadir PSA value (P < 0.001). A high PSA nadir value and short TTN may predict the risk of BCR after successful RP, aiding the identification of candidates for adjuvant or salvage therapies after RP.

Increasing incidence of prostate cancer in Taiwan: A study of related factors using a nationwide health and welfare database.

Over the past decades, the incidence of prostate cancer in Taiwan kept rising. Many possible factors including the utility of prostate specific antigen tests, lifestyle remodeling, and patient's comorbidities may contribute to the increasing of incidence or prostate cancer. We aim to use the nationwide Health and Welfare Database (HWD) to investigate possible associated factors.We used HWD, a nationwide database of medical information, to assess the incidence of prostate cancer, utilization of prostate-specific antigen (PSA) test, and underlying diseases of patients and to evaluate whether there was a common trend among these factors.In total, 32,508 patients with newly diagnosed prostate cancer from 2006 to 2013 were identified. The incidence rate of prostate cancer per 100,000 men increased from 35.47 in 2006 to 52.87 in 2012. The number of patients with prostate cancer and underlying diseases related to metabolic syndrome increased every year. The number of total PSA tests and patients undergoing PSA testing, as well as average times of PSA testing per person in the whole population, increased every year. The average PSA test times of patients with newly diagnosed prostate cancer within 3 years before the diagnosis of prostate cancer also increased every year. There was a high correlation between the average PSA test times and the number of patients with newly diagnosed prostate cancer (r = 0.9734).The trends of incidence of prostate cancer, utilization of PSA testing, and underlying diseases related to metabolic syndrome at the diagnoses of cancer were similar, increasing every year in the study period. The results suggested that increasing use of PSA tests may increase the diagnosis of prostate cancers. Underlying diseases related to metabolic syndrome might also affect the incidence of prostate cancer.

Establishment of age-related prostate-specific antigen (PSA) reference limits in the Algerian population: A comparison of four indirect methods.

BACKGROUND AND AIMS: Age and ethnic related reference limits (Rls) for prostate-specific antigen (PSA), improve its diagnostic accuracy as a screening tool for prostate cancer (PCa). But, their establishment by clinical laboratories is seldom achieved due to the expense of the gold standard procedure. We used an alternative approach to produce our specific RIs. MATERIALS AND METHODS: Laboratory results over a 4-year period (1491 results of total PSA and 989 results of free PSA) were retrieved from our laboratory information system. An inclusion/exclusion process was applied. To estimate age-related 95th percentiles, Hoffmann, Bhattacharya and maximum likelihood methods followed by a linear regression model were applied based on mixed dataset and a quantile regression with restrictive cubic splines model were applied based on truncated dataset. To verify these age related RIs, an agreement analysis were used with respect to the percentage of free PSA (%fPSA) 26.4% positives as a surrogate for PCa. RESULTS: The PSA 95th percentiles using Hoffmann, Bhattacharya, maximum likelihood and quantile regression methods respectively were 3.0, 2.6, 2.3 and 2.8 ng/mL for men 40 to 49 years old; 4.1, 3.3, 2.8 and 3.2 ng/mL for men 50 to 59 years old; 5.6, 4.2, 3.4 and 3.5 ng/mL for men 60-69 years old; 7.5, 5.4, 4.1 and 3.9 ng/mL for men 70-79 years old. The Bhattacharya, maximum likelihood and quantile regression age-related Rls reflected better % fPSA positives. CONCLUSION: Our findings suggest that age related total PSA reference limits may be derived by retrospective analysis of intra-laboratory data using the quantile regression model or the Bhattacharya and maximum likelihood method, followed by a linear regression model.

A predictive model for prostate cancer incorporating PSA molecular forms and age.

The diagnostic specificity of prostate specific antigen (PSA) is limited. We aimed to characterize eight anti-PSA monoclonal antibodies (mAbs) to assess the prostate cancer (PCa) diagnostic utility of different PSA molecular forms, total (t) and free (f) PSA and PSA complexed to α1-antichymotrypsin (complexed PSA). MAbs were obtained by immunization with PSA and characterized by competition studies, ELISAs and immunoblotting. With them, we developed sensitive and specific ELISAs for these PSA molecular forms and measured them in 301 PCa patients and 764 patients with benign prostate hyperplasia, and analyzed their effectiveness to discriminate both groups using ROC curves. The free-to-total (FPR) and the complexed-to-total PSA (CPR) ratios significantly increased the diagnostic yield of tPSA. Moreover, based on model selection, we constructed a multivariable logistic regression model to predictive PCa that includes tPSA, fPSA, and age as predictors, which reached an optimism-corrected area under the ROC curve (AUC) of 0.86. Our model outperforms the predictive ability of tPSA (AUC 0.71), used in clinical practice. In conclusion, The FPR and CPR showed better diagnostic yield than tPSA. In addition, the PCa predictive model including age, fPSA and complexed PSA, outperformed tPSA detection efficacy. Our model may avoid unnecessary biopsies, preventing harmful side effects and reducing health expenses.

Dual-Mode Electrochemical Assay of Prostate-Specific Antigen Based on Antifouling Peptides Functionalized with Electrochemical Probes and Internal References.

Sensitive and selective detection of target analytes in complex biological samples is currently a major challenge. Herein we constructed a dual-mode antifouling electrochemical sensing platform for the detection of prostate-specific antigen (PSA) based on two kinds of antifouling peptides functionalized with a graphene oxide-Fe3O4-thionine (GO-Fe3O4-Thi) probe and internal reference ferrocene (Fc), respectively. The longer peptide (Pep1) modified with the GO-Fe3O4-Thi probe was designed to contain a peptide sequence (HSSKLQK) capable of being recognized and cut by PSA. The GO-Fe3O4-Thi probe functions not only as a peroxidase mimick (GO-Fe3O4) but also works as an electrochemical probe due to the presence of thionine (Thi). The concentration of PSA can be measured through both the increase of differential pulse voltammetry (DPV) signal change of Thi and the decrease of chronoamperometry (CA) signal of the reduction of H2O2 electrocatalyzed by GO-Fe3O4. The shorter peptide (Pep2) was tagged with Fc, whose DPV signal remained constant and was independent of the presence of PSA, and it was used as an internal reference to ensure the reliability and accuracy of the measurement. The dual-mode PSA sensor exhibits a wide linear range from 5 pg/mL to 10 ng/mL, with low detection limits of 0.76 and 0.42 pg/mL through DPV and CA modes, respectively. More importantly, owing to the antifouling capability of the designed peptides, the biosensor performances remained operable even in human serum, indicating feasibility of the electrochemical biosensor for practical PSA quantification in complex samples.

Continued provision of WHO International Standards for total and free PSA: Content and commutability of replacement preparations.

OBJECTIVES: Replacements are required for the WHO International Standards (IS) for free PSA, coded 96/668 and total PSA (90:10), coded 96/670, which were established in 1999 to support efforts to harmonise PSA assays and address non-equimolarity. An important consideration is that the introduction of the replacements should have minimal impact on PSA measurements. DESIGN AND METHODS: We report the development of a replacement strategy, informed by field assessment of preparations through an external quality assessment scheme and the subsequent evaluation of the candidate ISs in worldwide collaborative studies. RESULTS: By immunoassay, data from participants confirmed the value assigned to the current standards. Robust geometric mean estimates of the free PSA content of the candidate replacement for 96/668 coded 17/102 was 0.533 µg/ampoule (n = 21). The ratio of the content estimates of 17/102:96/668 was 0.516 (GCV 12.5%, n = 21). Robust geometric mean estimates of the total PSA content of the candidate replacement for 96/670, coded 17/100, was 0.505 µg/ampoule (n = 22). The ratio of the content estimates of 17/100:96/670 was 0.490 (GCV 5.3%, n = 22). Through concomitant measurement of a panel of 15 representative patient samples, the candidate ISs were shown to exhibit commutability with patient samples that was comparable with that of the current ISs. CONCLUSION: On the basis of these results, the preparations coded 17/102 and 17/100 were established by the WHO Expert Committee on Biological Standardization as the 2nd ISs for free and total PSA (PSA-ACT+free PSA) respectively, with assigned contents of 0.53 µg/ampoule and 0.50 µg/ampoule.

Impact of Metabolic Diseases, Drugs, and Dietary Factors on Prostate Cancer Risk, Recurrence, and Survival: A Systematic Review by the European Association of Urology Section of Oncological Urology.

CONTEXT: To date, established risk factors for prostate cancer (PCa) are limited to age, race, family history, and certain genetic polymorphisms. Despite great research efforts, available evidence on potentially modifiable risk factors is conflicting. Moreover, most studies on PCa risk factors did not consider the impact of prostate-specific antigen (PSA) testing on PCa diagnosis. OBJECTIVE: To provide a detailed overview of the latest evidence on the role of metabolic diseases, drugs, and dietary factors for risk of PCa incidence, recurrence, and survival in men exposed to PSA testing. EVIDENCE ACQUISITION: A systematic review of the English-language literature was performed using the MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations. Randomized, case-control, or cohort studies published during the periods 2008-2017 (on drugs and metabolic diseases) and 2003-2017 (on dietary factors), with extensive follow-up (≥8-10yr for studies on PCa risk; ≥2-5yr for studies on PCa recurrence, progression, and survival, depending on the review subtopic) and adjusting of the analyses, beyond established risk factors, for either rate of PSA testing (for risk analyses) or PCa stage and primary treatment (for survival analyses), were eligible for inclusion. EVIDENCE SYNTHESIS: Overall, 39 reports from 22 observational studies were included. Studies were heterogeneous regarding definitions of exposure or outcomes, length of follow-up, risk of bias, and confounding. For some risk factors, evidence was insufficient to assess potential effects, while for others there was no evidence of an effect. For selected risk factors, namely metformin, aspirin and statin use, diabetes, obesity, and specific dietary intakes, there was low-quality evidence of modest effects on PCa risk. CONCLUSIONS: Current evidence from long-term observational studies evaluating the effect of drugs, metabolic diseases, and dietary factors for PCa risk considering the impact of PSA testing is still not conclusive. Future research is needed to confirm the associations suggested by our review, exploring their potential biological explanations and selecting those risk factors most likely to trigger effective public health interventions. PATIENT SUMMARY: We reviewed the available studies published in the recent literature on the potential role of drugs, metabolic diseases, and food and dietary factors for the risk of prostate cancer, considering the impact of prostate-specific antigen testing on prostate cancer diagnosis. We found that for some factors data are currently insufficient to make definitive conclusions, while for others available studies seem to indicate an effect on the risk of prostate cancer.

Impact of Prostatic-specific Antigen Threshold and Screening Interval in Prostate Cancer Screening Outcomes: Comparing the Swedish and Finnish European Randomised Study of Screening for Prostate Cancer Centres.

BACKGROUND: The European Randomised Study of Screening for Prostate Cancer trial has shown a 21% reduction in prostate cancer (PC) mortality with prostate-specific antigen (PSA)-based screening. Sweden used a 2-yr screening interval and showed a larger mortality reduction than Finland with a 4-yr interval and higher PSA cut-off. OBJECTIVE: To evaluate the impact of screening interval and PSA cut-off on PC detection and mortality. DESIGN, SETTING, AND PARTICIPANTS: We analysed the core age groups (55-69 yr at entry) of the Finnish (N=31 866) and Swedish (N=5901) screening arms at 13 yr and 16 yr of follow-up. Sweden used a screening interval of 2 yr and a PSA cut-off of 3.0ng/ml, while in Finland the screening interval was 4 yr and the PSA cut-off 4.0ng/ml (or PSA 3.0-3.9ng/ml with free PSA<16%). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We compared PC detection rate and PC mortality between the Finnish and Swedish centres and estimated the impact of different screening protocols. RESULTS AND LIMITATIONS: If the Swedish screening protocol had been followed in Finland, 122 additional PC cases would have been diagnosed at screening, 84% of which would have been low-risk cancers, and four leading to PC death. In contrast, if a lower PSA threshold had been applied in Finland, at least 127 additional PC would have been found, with 19 PC deaths. CONCLUSIONS: The small number of deaths among cases that would have been potentially detectable in Finland with the Swedish protocol (or those that would have been missed in Sweden with the Finnish approach) is unlikely to explain the differences in mortality in this long of a follow-up. PATIENT SUMMARY: A prostate-specific antigen threshold of 3ng/ml versus 4ng/ml or a screening interval of 2 yr instead of 4 yr is unlikely to explain the larger mortality reduction achieved in Sweden compared with Finland.

Changing Incidence of Metastatic Prostate Cancer by Race and Age, 1988-2015.

BACKGROUND: Screening for prostate cancer (PCa) has dramatically declined in the United States (US) since the United States Preventive Services Task Force recommended against routine prostate-specific antigen (PSA)-based PCa screening in all men in 2012. This led to dramatic reductions in the diagnosis of localized disease across all clinical risk groups. OBJECTIVE: In light of decreased PSA screening for men in the US, we sought to study trends in newly diagnosed metastatic PCa incidence and how this may vary by race and age. DESIGN, SETTING, AND PARTICIPANTS: We analyzed new PCa incidence by stage at diagnosis between 1988 and 2015 within the Cancer Registry of Greater California. We further stratified the patients by age and four major race/ethnicity groups (Hispanic, non-Hispanic white [NHW], non-Hispanic black [NHB], and non-Hispanic Asian/Pacific Islander [API]). Incidence rates were calculated and compared per 100000 and age-adjusted to the 2000 US standard population. OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS: The primary outcome was incidence of metastatic PCa at the time of cancer diagnosis. Joinpoint regression program was used to detect changes in incidence and to calculate the average percent change (APC) over time. All data were analyzed using SEER*Stat version 8.1.15 and Joinpoint Regression Program version 4.1.0, and a two-sided p value of <0.05 was considered statistically significant. RESULTS AND LIMITATIONS: Adjusted rates of metastatic PCa incidence for NHW men significantly increased by 4.3% since 2010, while remaining down (NHB, Hispanic) or level (API) for other racial groups. Stratified by age, incidence of metastatic disease for all races has increased significantly for men aged 64-75 yr since 2008 with an APC of 2.8% while remaining level for other age groups. The limitations of our study include retrospective design and no data on extent of PSA screening in the study cohort. CONCLUSIONS: Incidence rates of newly diagnosed metastatic PCa have significantly increased for NHW men and men aged 65-74 yr. PATIENT SUMMARY: Prostate-specific antigen screening has declined in the Unites States with a subsequent sharp drop in the incidence of screen-detected localized prostate cancer. The incidence of men presenting with metastatic disease seems to be rising recently, and men should continue to discuss the benefits of PSA screening with their primary care doctor.

Current guidelines for prostate cancer screening: A systematic review and minimal core proposal.

OBJECTIVE: Considering the importance of screening for prostate cancer, the possibility of damage resulting from indiscriminate screening and the difficulty of disclosure and adherence to the main guidelines on the subject, we aimed to identify current guidelines, look for common approaches and establish a core of conducts. METHOD: Systematic review of the literature on screening practice guidelines for prostate cancer searching the databases PubMed, Lilacs and Google Scholar and active search in the sites of several national health entities. RESULTS: Twelve (12) guidelines were selected, whose analysis resulted in the identification of six common points of conduct, with the following minimum core of recommendations: (1) screening indication or not: must be individualized, and preceded by an informed decision; (2) tests used: PSA with or without rectal digital examination; (3) age at which initiate testing in men in general risk: 50-55 years; (4) age at which to initiate testing in men at increased risk: 40-45 years; (5) the interval between screening: annual or biennial; and (6) age at which to discontinue testing: 70 years-old or life expectancy less than 10 years. CONCLUSION: Although there are differences between them, it was possible to establish a minimum core of conducts that may be useful in the daily practice of the physician.

Current guidelines for prostate cancer screening: A systematic review and minimal core proposal / Guias de conduta vigentes para o rastreamento do câncer de próstata: uma revisão sistemática e proposta de núcleo mínimo

Summary Objective: Considering the importance of screening for prostate cancer, the possibility of damage resulting from indiscriminate screening and the difficulty of disclosure and adherence to the main guidelines on the subject, we aimed to identify current guidelines, look for common approaches and establish a core of conducts. Method: Systematic review of the literature on screening practice guidelines for prostate cancer searching the databases PubMed, Lilacs and Google Scholar and active search in the sites of several national health entities. Results: Twelve (12) guidelines were selected, whose analysis resulted in the identification of six common points of conduct, with the following minimum core of recommendations: (1) screening indication or not: must be individualized, and preceded by an informed decision; (2) tests used: PSA with or without rectal digital examination; (3) age at which initiate testing in men in general risk: 50-55 years; (4) age at which to initiate testing in men at increased risk: 40-45 years; (5) the interval between screening: annual or biennial; and (6) age at which to discontinue testing: 70 years-old or life expectancy less than 10 years. Conclusion: Although there are differences between them, it was possible to establish a minimum core of conducts that may be useful in the daily practice of the physician.

Resumo Objetivo: Considerando a importância do rastreamento de câncer de próstata, a possibilidade de dano decorrente do rastreamento indiscriminado, a dificuldade de divulgação e adesão às diretrizes sobre o assunto, objetivamos identificar as principais diretrizes vigentes, procurar pontos de abordagem comuns e estabelecer um núcleo mínimo de condutas. Método: Revisão sistemática da literatura sobre guias de prática de rastreamento para câncer de próstata nas bases Pubmed, Lilacs e Google Scholar, além de busca ativa nos sítios de diversas entidades de saúde nacionais. Resultados: Foram selecionadas 12 diretrizes, cuja análise resultou na identificação de seis pontos comuns de conduta, com o seguinte núcleo mínimo de recomendações: (1) a indicação ou não de rastreamento: deve ser individualizada e precedida de uma decisão informada; (2) os exames utilizados: PSA com ou sem exame digital retal; (3) a idade de início geral: 50-55 anos; (4) a idade de início em homens com risco aumentado: 40 anos; (5) o intervalo entre os rastreamentos: anual ou bienal; e (6) a idade de suspensão do rastreamento: 70 anos ou expectativa de vida menor que 10 anos. Conclusão: Embora existam divergências entre elas, foi possível estabelecer um núcleo mínimo de condutas que podem ser úteis na prática diária do médico.

Papel actual del antígeno prostático específico (PSA) y sus derivados en el diagnóstico del cáncer de próstata / Current role of protatic specific antigen (PSA) and its by-products in the diagnosis of prostate cancer

La incorporación del antígeno prostático específico (PSA) a la clínica revolucionó el diagnóstico y modificó la epidemiología del cáncer de próstata (CaP). Aunque le faltan muchas de las características de un marcador tumoral ideal, es el marcador más usado para el diagnóstico y seguimiento de cualquier tipo cáncer. Representa la mejor herramienta clínica de las que disponemos en la actualidad para el cribado y estadificación del CaP. Por contra, la mayor limitación que presenta el PSA es su falta de especificidad tumoral. El empleo de los derivados y de las isoformas moleculares del PSA trata de solventar, al menos en parte, sus limitaciones. De hecho, la utilización del cociente del PSA libre (%fPSA) y de la densidad del PSA (PSAD) aumenta de forma significativa la especificidad del test en el diagnóstico y, el uso de los derivados que evalúan la cinética temporal del PSA (velocidad del PSA (PSAV) y tiempo de duplicación del PSA (PSADT)) representan herramientas de gran utilidad para estimar el pronóstico durante el tratamiento y seguimiento de la enfermedad. El mayor avance que se ha producido en los últimos años ha venido del análisis de la isoforma precursora (-2)pPSA y del índice phi. Ambos marcadores han demostrado mejorar los resultados de sensibilidad y especificidad obtenidos hasta ahora, ocasionando una disminución de biopsias innecesarias. Es probable que con el desarrollo de nuevos marcadores para el CaP que está habiendo, en pocos años se modifique el papel que el PSA tiene en el diagnóstico y en la estadificación de la enfermedad

Incorporation of prostatic specific antigen (PSA) to clinical practice was a revolution in the diagnosis and modified the epidemiology of prostate cancer (PCa). Although it lacks of many characteristics of an ideal tumor marker, it is the marker most used for diagnosis and follow up of any kind of cancer. It represents the best clinical tool we have available today for screening and staging of PCa. On the contrary, its greatest limitation is the lack of tumor specificity. The use of PSA by-products and molecular isoforms tries to solve, at least partially, its limitations. Indeed, the use of FreePSA ratio (%fPSA) ad PSA density (PSAD) increase significantly the specificity of the diagnostic test and, the use of derivatives that evaluate time kinetics of PSA (PSA velocity (PSAV) and PSA doubling time (PSADT)) represents a very useful tool for prognosis estimation during treatment and follow up of the disease. The greatest advance over the last years comes from the analysis of the predecessor isoform (-2) pPSA and the phi Index. Both markers have demonstrated to improve the sensitivity and specificity results obtained to date, resulting in a decrease of unnecessary biopsies. Probably, with the ongoing development of new markers for PCa , the role of PSA on disease diagnosis and staging would be modified in a few years

Guideline for referral of patients with suspected prostate cancer by family physicians and other primary care providers.

OBJECTIVE: The aim of this guideline is to assist FPs and other primary care providers with recognizing features that should raise their suspicion about the presence of prostate cancer in their patients. COMPOSITION OF THE COMMITTEE: Committee members were selected from among the regional primary care leads from the Cancer Care Ontario Provincial Primary Care and Cancer Network and from among the members of the Cancer Care Ontario Genitourinary Cancer Disease Site Group. METHODS: This guideline was developed through systematic review of the evidence base, synthesis of the evidence, and formal external review involving Canadian stakeholders to validate the relevance of recommendations. REPORT: Evidence-based guidelines were developed to improve the management of patients presenting with clinical features of prostate cancer within the Canadian context. CONCLUSION: These guidelines might lead to more timely and appropriate referrals and might also be of value for informing the development of prostate cancer diagnostic programs and for helping policy makers to ensure appropriate resources are in place.

Prostate-specific antigen and prostate-specific antigen velocity as threshold indicators in 11C-acetate PET/CTAC scanning for prostate cancer recurrence.

PURPOSE: The aim of this study was to identify which patient characteristics are associated with the highest likelihood of positive findings on 11C-acetate PET/computed tomography attenuation correction (CTAC) (PET/CTAC) scan when imaging for recurrent prostate cancer. METHODS: From 2007 to 2011, 250 11C-acetate PET/CTAC scans were performed at a single institution on patients with prostate cancer recurrence after surgery, brachytherapy, or external beam radiation. Of these patients, 120 met our inclusion criteria. Logistic regression analysis was used to examine the relationship between predictability of positive findings and patients' characteristics, such as prostate-specific antigen (PSA) level at the time of scan, PSA kinetics, Gleason score, staging, and type of treatment before scan. RESULTS: In total, 68.3% of the 120 11C-acetate PET/CTAC scans were positive. The percentage of positive scans and PSA at the time of scanning and PSA velocity (PSAV) had positive correlations. The putative sensitivity and specificity were 86.6% and 65.8%, respectively, when a PSA level greater than 1.24 ng/mL was used as the threshold for scanning. The putative sensitivity and specificity were 74% and 75%, respectively, when a PSAV level greater than 1.32 ng/mL/y was used as the threshold. No significant associations were found between scan positivity and age, PSA doubling time, Gleason score, staging, or type of treatment before scanning. CONCLUSIONS: This retrospective study suggests that threshold models of PSA greater than 1.24 ng/mL or PSAV greater than 1.32 ng/mL per year are independent predictors of positive findings in 11C-acetate PET/CTAC imaging of recurrent prostate cancer.

Have screening harms become newsworthy? News coverage of prostate and colorectal cancer screening since the 2008 USPSTF recommendation changes.

In 2008, the US Preventive Services Task Force updated its recommendations to discourage screening for prostate cancer in men over 75 and for colorectal cancer in adults over 85. We aimed to determine whether newspapers portrayed these screenings differently after these recommendation changes. A quantitative content analysis included articles on prostate-specific antigen (PSA) testing or colonoscopy in US newspapers from 2005 to 2012. Outcomes included the number of benefits and harms mentioned and the gist expert and lay readers might get from articles. Benefits in PSA articles (n = 222) and harms and benefits in colonoscopy articles (n = 65) did not change over time. Mentions of PSA harms increased after 2008 (p < .01). Expected expert gist of PSA articles became more negative after 2008 (p < .01). Expected lay gist was positive and did not change. News coverage of PSA testing harms increased without a decrease in the discussion of benefits. Consumers, especially lay consumers, are receiving unbalanced information on cancer screening.

Variability of assay methods for total and free PSA after WHO standardization.

The variability of total PSA (tPSA) and free PSA (fPSA) results among commercial assays has been suggested to be decreased by calibration to World Health Organization (WHO) reference materials. To characterize the current situation, it is necessary to know its impact in the critical cutoffs used in clinical practice. In the present study, we tested 167 samples with tPSA concentrations of 0 to 20 µg/L using seven PSA and six fPSA commercial assays, including Access, ARCHITECT i2000, ADVIA Centaur XP, IMMULITE 2000, Elecsys, and Lumipulse G1200, in which we only measured tPSA. tPSA and fPSA were measured in Access using the Hybritech and WHO calibrators. Passing-Bablok analysis was performed for PSA, and percentage of fPSA with the Hybritech-calibrated access comparison assay. For tPSA, relative differences were more than 10 % at 0.2 µg/L for ARCHITECT i2000, and at a critical concentration of 3, 4, and 10 µg/L, the relative difference was exceeded by ADVIA Centaur XP and WHO-calibrated Access. For percent fPSA, at a critical concentration of 10 %, the 10 % relative difference limit was exceeded by IMMULITE 2000 assay. At a critical concentration of 20 and 25 %, ADVIA Centaur XP, ARCHITECT i2000, and IMMULITE 2000 assays exceeded the 10 % relative difference limit. We have shown significant discordances between assays included in this study despite advances in standardization conducted in the last years. Further harmonization efforts are required in order to obtain a complete clinical concordance.

Suitability of quality control materials for prostate-specific antigen (PSA) measurement: inter-method variability of common tumor marker control materials.

BACKGROUND: Quality control materials with minimal inter-assay differences and clinically relevant proportions of different molecular forms of the analyte are needed to optimize intra- and inter-laboratory accuracy and precision. METHODS: We assessed if clinically relevant total prostate-specific antigen (tPSA) levels were present in seven commercially available Multi Constituent Tumor Marker Controls (MC-TMC). Further, we determined the concentration of free PSA (fPSA) and calculated the percentage of free PSA (%fPSA) in all materials. Finally, we determined variability of TMC materials across several commonly used PSA platforms. RESULTS: All MC-TMC materials contained at least one concentration of tPSA in normal and pathologic range. Control materials varied in the amount of fPSA and %fPSA, with most controls consisting of fPSA only and only one MC-TMC containing medically relevant levels of around 35% fPSA. Only a minority of MC-TMC materials showed minimal variability across four PSA methods while the majority of PSA controls showed wide inter-method differences. CONCLUSIONS: Use of many commercially available controls for PSA could lead to biased PSA measurements because they contain medically irrelevant proportions of fPSA and show significant variation among different PSA assay platforms.