Effect of digital rectal examination on serum complexed and free prostate-specific antigen and percentage of free prostate-specific antigen

Differentially expressed glycoproteins in pre- and post-digital rectal examination urine samples for detecting aggressive prostate cancer

Urinary glycoproteins associated with aggressive prostate cancer (AG-PCa) were previously reported using post-digital rectal examination (DRE) urine specimens. To explore the potential of using pre-DRE urine specimens for detecting AG-PCa, we compared glycoproteins between pre- and post-DRE urine specimens, verified the previously identified post-DRE AG-PCa-associated urinary glycoproteins in pre-DRE urine specimens, and explored potential new glycoproteins for AG-PCa detection in pre-DRE urine specimens. Quantitative glycoproteomic data were acquired for 154 pre-DRE urine specimens from 41 patients with no cancer at biopsy, 48 patients with non-AG-PCa (Gleason score = 6), and 65 patients with AG-PCa (Gleason score 7 or above). Compared to glycopeptides from the post-DRE urine data, humoral immunity-related proteins were enriched in pre-DRE urine samples, whereas cell mediated immune response proteins were enriched in post-DRE urine samples. Analyses of AG-PCa-associated glycoproteins from pre-DRE urine revealed that the three urinary glycoproteins, prostate-specific antigen (PSA), prostatic acid phosphatase (ACPP), and CD97 antigen (CD97) that were previously identified in post-DRE urine samples, were also observed as AG-PCa associated glycoproteins in pre-DRE urine. In addition, we identified three new glycoproteins, fibrillin 1 (FBN1), vitronectin (VTN), and hemicentin 2 (HMCN2), to be potentially associated with AG-PCa in pre-DRE urine specimens. In summary, glycoprotein profiles differ between pre- and post-DRE urine specimens. The identified AG-PCa-associated glycoproteins may be further evaluated in large cohort of pre-DRE urine specimens for detecting clinically significant PCa.

Digital rectal examination impact on PSA derivatives and prostate biopsy triggers: a contemporary study

OBJECTIVE

To evaluate the impact of the digital rectal exam (DRE) on PSA measurements and clinical decision-making.

METHODS

Healthy male volunteers between 50 and 70 years old were recruited during a 30-day public screening program. PSA levels were measured using two different methods (standard enhanced chemiluminescence immunoassay-ECLIA, and novel immunochromatography assay-ICA/rapid PSA) in the same blood sample. Two blood samples were drawn; first before DRE and the second 30-40 min after DRE. The effect of DRE on PSA levels and its impact on clinical decision-making for individual patients were evaluated based on different biopsy trigger cutoffs.

RESULTS

ECLIA-PSA was measured in 74 participants both pre- and 37 ± 5 min post-DRE, mean age 57.2 ± 8.3 years, and mean prostate volume 33.6 (20-80) cm³. Both total and free ECLIA-PSA increased significantly after DRE (mean increase of 0.47 and 0.26 ng/ml, respectively, both p < 0.001). Different internationally accepted biopsy triggers were reached after DRE only: 5 total PSA > 3 ng/ml, 13 increase > 0.75 ng/ml, 3 PSA density > 0.15, and 1 free/total PSA < 0.18. On two occasions, patients were pushed away from biopsy trigger after DRE due to free/total PSA > 0.18. ICA-PSA was detectable (> 2.0 ng/ml) in 5 of 45 measured samples (11%) before DRE and 13/45 (29%) after DRE, p = 0.0316. Four among five detectable ICA-PSA tests increased after DRE.

CONCLUSION

Performing DRE immediately before PSA measurement might change the clinical decision-making on a significant number of occasions (roughly 1 in 3); even though the mean increase (0.47 ng/ml) looks deceivingly small. Further studies are required that include gold standard tests (biopsy, or imaging).

Contributions of Social Factors to Disparities in Prostate Cancer Risk Profiles among Black Men and Non-Hispanic White Men with Prostate Cancer in California

BACKGROUND

Black men are more likely than Non-Hispanic White (NHW) men to be diagnosed with high-risk prostate cancer. We examined the extent to which social factors were associated with differences in prostate cancer risk profiles between Black men and NHW men [using a modification to the original D'Amico risk groups based on prostate specific antigen (PSA), Gleason score (GS), and TNM stage (stage)], based on individual and combined clinicopathologic characteristics.

METHODS

We conducted a cross-sectional population-based study of 23,555 Black men and 146,889 NHW men diagnosed with prostate cancer in the California Cancer Registry from 2004 to 2017. We conducted multivariable logistic regression to examine the association of year of diagnosis, block group-level neighborhood socioeconomic status (nSES), marital status, and insurance type on differences in prostate cancer risk profiles between Black and NHW men.

RESULTS

High PSA (>20 ng/mL), GS, stage, individually and combined prostate cancer risk profiles were more common among Black men versus NHW men. In fully adjusted models, relative to NHW men, we observed a persistent 67% increased odds of high PSA among Black men. nSES was the factor most strongly associated with racial disparity in high PSA, accounting for 25% of the difference. Marital status was the factor that was second most associated with a racial disparity.

CONCLUSIONS

nSES was the factor most strongly associated with racial disparities in high PSA prostate cancer.

IMPACT

The influence of nSES on racial disparities in PSA, GS, stage, and prostate cancer risk profiles warrants further consideration.

Lifestyle factors and prostate-specific antigen

Background:

Increasing prostate cancer awareness has meant that more men are seeking out prostate-specific antigen (PSA) testing than ever before. Prostate cancer is now the most common malignancy in men, affecting one in eight. This article addresses lifestyle factors that may elevate PSA readings.

Methods:

A systematic review of the literature was performed using Medline for studies examining the association of PSA and lifestyle factors, including exercise, diet, sexual function as well as medication use. Further resources were identified from the reference list of retrieved articles.

Results:

Minimal level 1 evidence on the association of PSA with lifestyle factors was identified. Weak and generally inconsistent evidence was found on the effect of cycling and sexual activity. Diabetes and obesity did have inversely proportional effects on PSA values in large cohort studies. There was no evidence for an independent effect of different types of food to PSA. With regard to medications, the greatest impact is from 5-alpha reductase inhibitors, and these are used as a hair-loss treatment. Statins, non-steroidal anti-inflammatory drugs and thiazide diuretics can also have a clinically significant impact on PSA levels but unlikely to alter management.

Discussion:

For a small group of patients, cautious counselling on the factors summarised here before they have their blood tests may prevent undue stress and anxiety, particularly in those with borderline PSA results. Due to the inconsistency of results and lack of level 1a evidence, if there is reasonable suspicion for prostate cancer, a patient should still always be referred to a specialist.

Level of evidence:

Level 4.

Tobacco and marijuana use and their association with serum prostate-specific antigen levels among African American men in Chicago

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AA men are under-represented in PSA research, a biomarker of prostate cancer aggresiveness.

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Cigarette smoking was associated with an increase in PSA among older AA men.

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Tobacco use was associated with an increase in PSA among older AA men.

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Marijuana use was associated with a decrease in PSA among older AA men.

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Future behavioral risk factor studies linked to biopsy outcomes are warranted.

African American (AA) men experience more than twice the prostate cancer mortality as White men yet are under-represented in academic research involving prostate-specific antigen (PSA), a biomarker of prostate cancer aggressiveness. We examined the impact of self-reported tobacco (cigarette pack-years and current tobacco use including e-cigarettes) and current regular marijuana use on serum PSA level based on clinical laboratory testing among 928 AA men interviewed 2013–2018 in Chicago. We defined outcome of elevated PSA ≥ 4.0 ng/mL for logistic regression models and continuous PSA increases for general linear models. All models were adjusted for age, sociodemographic characteristics, healthcare utilization, body mass index, and self-reported health. Among 431 AA men age ≥ 55 years, we observed ∼ 5 times the odds of elevated PSA among those with > 1 pack-years of cigarette smoking vs. never-smokers (odds ratio [OR] = 5.09; 95% confidence interval [CI] = 1.57–16.6) and a quarter the odds of elevated PSA among current marijuana users vs. non-users (OR = 0.27; 95% CI = 0.08–0.96). PSA increased on average 1.20 ng/mL among other current tobacco users vs. non-users. Among older AA men, cigarette smoking history and current tobacco use were positively associated with an increase in PSA levels and current marijuana use were inversely associated with PSA levels. Future work with studies of diverse patient populations with cancer outcomes are needed to assess whether these behavioral characteristics contribute to racial/ ethnic disparities in prostate cancer outcomes. Our study provides novel evidence regarding potential differences in PSA levels among older AA men according to behavioral characteristics.

Therapeutic use of pulsed electromagnetic field therapy reduces prostate volume and lower urinary tract symptoms in benign prostatic hyperplasia

Background

Benign prostatic hyperplasia (BPH) etiology remains poorly understood, but chronic low‐grade inflammation plays a role. Pulsed electromagnetic field therapy (PEMF) (1‐50 Hz) is effective in reducing tissue inflammation.

Objectives

We designed a pilot study to evaluate the effects of PEMF on prostate volume (PV) in BPH.

Materials and Methods

This is a prospective interventional trial on 27 naive patients with BPH and lower urinary tract symptoms (LUTS). At baseline (V₀), all patients had blood tests, transrectal ultrasound, and questionnaires (IPSS, IIEF‐15) and received a perineal PEMF device (Magcell^®Microcirc, Physiomed Elektromedizin). PEMF was delivered on perineal area 5 minutes twice daily for 28 days, then (V₁) all baseline evaluations were repeated. Afterward, nine patients continued therapy for 3 more months (PT group) and 15 discontinued (FU group). A 4‐month evaluation (V₂) was performed in both groups.

Results

A reduction was observed both at V₁ and at V₂ in PV: PV_V0 44.5 mL (38.0;61.6) vs PV_V1 42.1 mL (33.7;61.5, P = .039) vs PV_V2 41.7mL (32.7;62.8, P = .045). IPSS was reduced both at V₁ and at V₂: IPSS_V0 11 (5.7;23.2) vs IPSS_V1 10 (6;16, P = .045) vs IPSS_V2 9 (6;14, P = .015). Baseline IPSS was related to IPSS reduction both at V₁ (r_s = 0.313;P = .003) and at V₂ (r_s = 0.664;P < .001). PV reduction in patients without metabolic syndrome (ΔPV_V1nMetS −4.7 mL, 95%CI −7.3;‐2.0) was greater than in affected patients (ΔPV_V1MetS 1.7 mL, 95%CI −2.69;6.1)(P = .017, Relative Risk_MetS = 6). No changes were found in gonadal hormones or sexual function.

Discussion

PEMF was able to reduce PV after 28 days of therapy. Symptoms improved in a short time, with high compliance and no effects on hormonal and sexual function or any side effects. Patients with moderate‐severe LUTS and without MetS seem to benefit more from this treatment.

Conclusion

PEMF reduces PV and improves LUTS in a relative short time, in BPH patients. These benefits seem greater in those patients with moderate‐severe LUTS but without MetS.

The effect of digital rectal exam on the 4Kscore for aggressive prostate cancer

BACKGROUND

The 4Kscore is a new commercially available blood-based diagnostic test which predicts risk for aggressive, clinically significant prostate cancer on prostate biopsy. The 4Kscore is currently restricted to patients who have not had a digital rectal exam (DRE) in the previous 96 h, owing to prior mixed data suggesting that prostate specific antigen (PSA) isoforms may increase by a statistically significant-if not necessarily clinically significant-amount shortly after DRE. Our primary objective was to determine if 4Kscore test results are affected by a preceding DRE.

METHODS

Participants at a Prostate Cancer Awareness Week screening event sponsored by the Prostate Conditions Education Council filled out clinical history questionnaires and had blood samples for 4Kscore testing drawn prior to DRE, then 15-45 min following DRE. Patients with prior cancer diagnosis, 5-alpha reductase inhibitor medication use, or lower urinary tract procedures in the prior 6 months were excluded, resulting in a population of 162 participants for analysis. Values were then compared to determine if there was a significant difference in 4Kscore following DRE.

RESULTS

A statistically significant increase was seen in levels of 3 kallikreins measured (total PSA, free PSA, and intact PSA; median <0.03 ng/mL for all). This resulted in a small but statistically significant decrease in post-DRE 4Kscore (median absolute score decrease 0.43%). Using a 4Kscore cutoff of 7.5% resulted in reclassification of 10 patients (6.2%), nine of whom were "downgraded" from above the cutoff to below.

CONCLUSIONS

If the blood draw for the 4 K score is performed after a screening DRE, there is a statistically significant difference in the 4 K score results, but in the vast majority of cases it would not affect clinical decision making.

Expressed prostatic secretion biomarkers improve stratification of NCCN active surveillance candidates: performance of secretion capacity and TMPRSS2:ERG models

PURPOSE

Active surveillance is a viable patient option for prostate cancer provided that a clinical determination of low risk and presumably organ confined disease can be made. To standardize risk stratification schemes the NCCN (National Comprehensive Cancer Network®) provides guidelines for the active surveillance option. We determined the effectiveness of expressed prostatic secretion biomarkers for detecting occult risk factors in NCCN active surveillance candidates.

MATERIALS AND METHODS

Expressed prostatic secretion specimens were obtained before robot-assisted radical prostatectomy. Secretion capacity biomarkers, including total RNA and expressed prostatic secretion specimen volume, were measured by standard techniques. RNA expression biomarkers, including TXNRD1 mRNA, prostate specific antigen mRNA, TMPRSS2:ERG fusion mRNA and PCA3 mRNA, were measured by quantitative reverse-transcription polymerase chain reaction.

RESULTS

Of the 528 patients from whom expressed prostatic secretions were collected 216 were eligible for active surveillance under NCCN guidelines. Variable selection on logistic regression identified 2 models, including one featuring types III and VI TMPRSS2:ERG variants, and one featuring 2 secretion capacity biomarkers. Of the 2 high performing models the secretion capacity model was most effective for detecting cases in this group that were up-staged or up-staged plus upgraded. It decreased the risk of up-staging in patients with a negative test almost eightfold and decreased the risk of up-staging plus upgrading about fivefold while doubling the prevalence of up-staging in the positive test group.

CONCLUSIONS

Noninvasive expressed prostatic secretion testing may improve patient acceptance of active surveillance by dramatically reducing the presence of occult risk factors among those eligible for active surveillance under NCCN guidelines.

Long distance bicycle riding causes prostate-specific antigen to increase in men aged 50 years and over

Objectives

To investigate whether bicycle riding alters total prostate-specific antigen (tPSA) serum concentrations in healthy older men.

Methods

129 male participants, ranging in age from 50 to 71 years (mean 55 years), rode in a recreational group bicycle ride of between 55 and 160 kilometers. Blood samples for tPSA analysis were drawn within 60 minutes before starting, and within 5 minutes after completing the ride. The pre-cycling and post-cycling tPSA values were log transformed for normality and compared using paired t-tests. Linear regression was used to assess the relationship between changes in tPSA with age and distance cycled.

Results

Bicycle riding caused tPSA to increase by an average of 9.5% (95% CI = 6.1–12.9; p<0.001) or 0.23 ng/ml. The number of participants with an elevated tPSA (using the standard PSA normal range cut-off of 4.0 ng/ml) increased from two pre-cycle to six post-cycle (or from five to eight when using age-based normal ranges). Univariate linear regression analysis revealed that the change in tPSA was positively correlated with age and the distance cycled.

Conclusions

Cycling causes an average 9.5% increase in tPSA, in healthy male cyclists ≥50 years old, when measured within 5 minutes post cycling. We considered the increase clinically significant as the number of participants with an elevated PSA, according to established cut-offs, increased post-ride. Based on the research published to date, the authors suggest a 24–48 hour period of abstinence from cycling and ejaculation before a PSA test, to avoid spurious results.

[Influencing of the PSA concentration in serum by physical exercise (especially bicycle riding)]

BACKGROUND

Sports and in particular cycling are assumed to influence PSA in serum. Controversial scientific results were the motivation to examine the influence of a standardized test on a cycling ergometer and a treadmill on PSA concentrations in elderly men with elevated PSA levels and a benign prostate hyperplasia.

MATERIAL AND METHODS

A total of 21 male volunteers (aged 61 ± 5 years, tPSA 7.7 ± 3.0 ng/ml and benign prostate hyperplasia with a prostate volume of 54 ± 18 ml) performed a 1 h cycling test on a cycling ergometer. A subgroup of 15 volunteers also performed a 1 h test on a treadmill. Blood samples were drawn before and several times after the cycling stress test up to 7 days afterwards (up to 120 min after the test on the treadmill) to determine total PSA (tPSA), complexed PSA (cPSA) and free PSA (fPSA).

RESULTS

The average increase in tPSA of 1.9 ± 1.7 ng/ml (25%) after the cycling exercise test was significant. After the treadmill exercise the PSA increase was not as high, but with 1.0 ± 1.0 ng/ml (12%) was also significant. On average the levels of PSA returned to the basic level 48 h after the cycling test, but in individual cases it took longer. fPSA showed the most noticeable increase after cycling with 92% on average. There was no correlation between increase in PSA and prostate volume.

CONCLUSIONS

Men should abstain from physical exercise, especially from cycling for several days and at least for 24 h before PSA measurements are carried out. This applies to patients with elevated PSA levels (>4 ng/ml) when a PSA follow-up is being carried out.

Diagnosis of prostate cancer

The contemporary challenge of prostate cancer diagnosis has been changed in the past decade from the endeavor to increase detection to that of detecting only those tumors that are clinically significant. Better interpretation of the role of prostate-specific antigen (PSA) and its kinetics as a diagnostic tool, the adoption of extended prostate biopsy schemes, and perhaps implementation of new transrectal ultrasound (TRUS) technologies promote the achievement of this clinical mission. This chapter reviews these issues as well as the change in practice of patient preparation for TRUS-biopsy and analgesia during it, the role of repeat and saturation prostate biopsies, and the interpretation of an incidental prostate cancer finding. Currently, the lifetime risk of a diagnosis of prostate cancer for North American men is 16%, compared to the lifetime risk of death from prostate cancer, which is 3% (Carter 2004). The advent of prostate-specific antigen (PSA) screening and transrectal ultrasonography (TRUS) has significantly impacted the detection of prostate cancer over the last 20 years. The mean age at diagnosis has decreased (Hankey et al. 1999; Stamey et al. 2004) and the most common stage at diagnosis is now localized disease (Newcomer et al. 1997; Stamey et al. 2004). The goal of prostate cancer screening is to detect only those men at risk for death from the disease at an early curable phase. The ambiguous natural history of this most common malignancy in men, being latent with questionable life-threatening potential in a large number of cases on the one hand, with only a relatively small number (though not negligible) of highly malignant cases on the other, propels many doubts about whether this is possible. This was famously phrased more than 20 years ago by Whitmore who asked: "Is cure possible for those in whom it is necessary; and is it necessary for those in whom it is possible?" This is probably even more relevant nowadays. During the past decade two factors influenced significantly the increased detection rate of prostate cancer in general and that of clinically insignificant prostate cancers in particular: the widespread use of serum PSA as a screening tool to a large extent and to a lesser though significant extent the application of extended multiple core biopsy schemes (Master et al. 2005). In fact, 75% of men in the United States aged 50 years and older have been screened with the PSA test (Sirovich et al. 2003). Outside of the screening context, which is dealt with in depth in Chap. 5, clinical suspicion of prostate cancer is raised usually by abnormal digital rectal examination (DRE) and/or by abnormal levels of serum PSA. Final diagnosis is achieved only based on positive prostate biopsies.

Effect of prostatic massage on serum complexed prostate-specific antigen levels

OBJECTIVES

To evaluate the effects of prostatic massage on the serum complexed PSA (cPSA) concentration in various prostatic diseases.

METHODS

A total of 51 men who presented to our outpatient clinic for the first time with symptoms of lower urinary outflow obstruction were included in this study. Blood samples were obtained from each patient before and 30 minutes after prostatic massage. Total PSA (tPSA), free PSA (fPSA), and cPSA levels were measured using a chemiluminescent enzyme immunoassay.

RESULTS

After prostatic massage, the tPSA and fPSA levels and fPSA/tPSA ratio increased significantly (P < 0.0001), and the increase in cPSA was minimal but statistically significant (P = 0.047). In patients with prostate cancer, no significant increase occurred in the mean forms of PSA (tPSA, cPSA, and fPSA/tPSA ratio), except for fPSA, after prostatic massage. We observed a greater increase in all PSA forms in the chronic prostatitis group.

CONCLUSIONS

In this study, prostatic massage increased serum cPSA concentration, but to a lesser extent than tPSA and fPSA.

Dosagem e correlação do antígeno prostático específico com as alterações histológicas dos anexos sexuais do hamster sírio

OBJETIVO: Verificar os níveis de PSA total no Hamster Sírio, Mesocricetus auratus, jovem e adulto e demonstrar possíveis correlações entre esses níveis com as alterações histológicas dos anexos sexuais: próstata, vesículas seminais e testículos. MÉTODO: Foram examinados dez (n=10) Hamsters jovens, com idade inferior a sete semanas de vida e vinte (n=20) Hamsters com idade superior a um ano. Fez-se a dosagem do PSA e estudo histológico dos anexos sexuais em ambos os grupos e procurou-se a correlação entre o PSA encontrado e as alterações histológicas. RESULTADOS: A média de idade para os animais jovens, (grupo controle), foi de 46,7 dias (Desvio-Padrão-DP=1,16). Nos animais adultos, (grupo experimental), a média de idade não foi determinada, embora todos apresentassem idade acima de um ano no momento da morte. A média do peso dos animais jovens quando foram mortos foi de 57kg e dos animais adultos 126,5g. O PSA foi dosado no plasma de todos os animais adultos e em sete dos animais jovens. Em três animais do grupo jovem o PSA não foi detectado. A média do PSA nos animais jovens foi de 0,252ng/mL (nanogramo por mililitro) e nos animais adultos de 0,325ng/mL. Os animais jovens não apresentaram alterações histológicas nos anexos sexuais examinados. Entre os Hamsters adultos, quatorze (70%) animais apresentaram alguma alteração nos anexos sexuais: dez (50%) apresentaram Hiperplasia Benigna da Próstata (HBP); um (5%) apresentou HBP, prostatite e inflamação das vesículas seminais; um (5%) inflamação supurativa das vesículas seminais; um (5%) apresentou infarto testicular e prostatite; um (5%) apresentou inflamação das vesículas seminais, sem HBP e prostatite. Não se detectou relação estatística entre os níveis de PSA e a ocorrência de HBP, embora os portadores da hiperplasia prostática exibissem médias de PSA bastante superiores às apresentadas pelos não portadores de hiperplasia. Não foram também determinadas relações estatísticas entre os níveis de PSA e as alterações das vesículas seminais e testículo. CONCLUSÕES: 1- O Hamster Sírio, Mesocricetus auratus, apresenta PSA sérico dosável e seu valor médio para o Hamster jovem é de 0,252ng/mL e no Hamster adulto é de 0,325ng/mL.2. Não foi possível correlacionar os níveis de PSA com as alterações histológicas encontradas nos anexos sexuais do Mesocricetus auratus.

Digital rectal examination (DRE) does not influence total serum levels of prostate specific antigen (tPSA), in individuals without prostate pathology

OBJECTIVE

To evaluate if the digital rectal examination (DRE) performed before determination of total serum prostate specific antigen (tPSA) influences the levels of this protein.

MATERIALS AND METHODS

Forty-eight men without a diagnosis of prostate pathology were assessed for tPSA levels, before and 30 minutes after DRE examination. Values of tPSA in the individuals' serum were measured by the electrochemoluminescence (ECLIA), in Roche's Elecys 1010 analyzer.

RESULTS

DRE examination induced a modest elevation in tPSA values in 34 of the 48 men, with a variation in mean elevation from 2.19% in the age range >/= 70 years to 11.96% in the age range of 60-69 years. Additionally, moderate decreases in values were detected in 11 individuals and 3 did not present any alteration following the procedure. Differences in mean values of tPSA, pre- and post-DRE were not statistically significant, neither in the total sample of individuals or in the age range groups.

CONCLUSION

DRE examination does not significantly influence the tPSA values in individuals under study.

Técnica para obtenção do aparelho geniturinário e dosagem do PSA (Prostate Specific Antigen) no hamster sírio, Mesocricetus auratus

Objetivo: Expor a técnica utilizada na colheita de sangue para dosagem do PSA ( Prostate Specific Antigen ) e retirada do aparelho geniturinário no hamster sírio, Mesocricetus auratus, e correlacionar os achados do PSA com as alterações histológicas dos anexos sexuais desse roedor. Métodos: Foram usados no experimento trinta (n= 30) Hamsters: dez (n=10) animais considerados jovens com idade média no momento da morte de 47,5 dias e vinte (n=20) animais considerados adultos com idade superior à um ano. Após serem anestesiados com cloridrato de quetamina e diazepam, foi colhido diretamente da veia cava, em nível de abdome superior, cerca de 1,5mL a 2,0mL de sangue para dosagem do PSA totalpelo método ELISA, com antígeno humano. Morriam após colheita do sangue. Constatado a morte do animal, fazia-se a laparotomia retirando-se em monobloco todo aparelho geniturinário para estudo histológico dos anexos sexuais. Correlacionou-se o PSA com as alterações histológicas encontradas. Resultados: Os animais após serem anestesiados com cloridrato de quetamina e diazepam intraperitonealmente, obteve-se um excelente plano anestésico, que possibilitou colher via trans-dérmica da veia cava inferior em abdome superior sangue para dosagem do PSA. O animal morria após colheita do sangue. Fazia-se a laparotomia, com retirada em monobloco do aparelho geniturinário para estudo histológico e comparação das alterações encontradas nos anexos sexuais com o PSA dosado. Entre os Hamsters Jovens a média do PSA encontrado foi de 0,252ng/mL. Desvio Padrão (DP) = 0,36. Entre os Hamsters adultos esta média foi de 0,325 ng/mL, DP= 0,12 . Quando comparou-se as médias do PSA entre os dois grupos de jovens e adultos obteve-se p= 0,0427. Dentre os Hamsters jovens, três apresentaram PSA não detectado. A análise histológica mostrou que, entre os animais jovens, não foi identificada qualquer alteração das estruturas microscópicas da próstata, vesículas seminais e testículos. Observou-se nos Hamsters adultos (n=20), setenta por cento de alterações nos anexos sexuais a saber: um caso (5%) de processo supurativo das vesículas seminais, um caso (5%) de processo inflamatório isolado das vesículas seminais, um caso (5%) de Processo inflamatório das vesículas seminais, HBP e prostatite concomitante e um caso (5%) de infarto testicular e prostatite. Onze animais (55%), dos Hamsters adultos, apresentaram HBP (Hiperplasia Benigna da Próstata). Conclusão: A técnica cirúrgica descrita mostrou-se eficiente para a obtenção dos orgãos e estruturas do aparelho geniturinário, estudo histológico desses orgãos e dosagem do PSA no Hamster Sírio, Mesocricetus auratus.

Long-distance mountain biking does not disturb the measurement of total, free or complexed prostate-specific antigen in healthy men

Purpose: Mechanical manipulation of the prostate is a generally accepted interfering factor for the measurement of prostate-specific antigen (PSA). However, only few studies have focused on common daily mechanical manipulations, such as bicycle riding. Furthermore, physical exercise is also supposed to modulate PSA serum concentration. Long-distance mountain biking is an excellent model to study the combined effect of mechanical prostate manipulation by bicycle riding and strenuous endurance exercise on total, free and complexed PSA (tPSA, fPSA, cPSA). Materials and methods: We investigated tPSA, fPSA and cPSA in 42 healthy male cyclists (mean age 35±6 years) before and after a 120 km off-road mountain bike race. Blood sampling was done before, 15 min and 3 h after the race. Results: Mean race time was 342±65 min. All athletes had normal serum levels of tPSA, fPSA or cPSA. None of these parameters was modified by the race. Conclusions: In healthy men the measurement of tPSA, fPSA and cPSA is not disturbed by preceding long distance mountain biking or endurance exercise. Based on the present data, there is no evidence for a recommendation to limit bicycle riding or physical activity before the measurement of tPSA, fPSA or cPSA.

Evolution of free, complexed, and total serum prostate-specific antigen and their ratios during 1 year of follow-up of men with febrile urinary tract infection

OBJECTIVES

To determine the serum values of free, complexed, and total prostate-specific antigen (PSA) and their ratios in men with febrile urinary tract infection (UTI) during 1 year of follow-up.

METHODS

A total of 54 men were prospectively enrolled in the study, and serum samples were obtained at the acute stage of the UTI and after 1, 3, 6, and 12 months.

RESULTS

Most men had a rise (median 3.1, 7.2, and 14.1 ng/mL, respectively) in free PSA (fPSA), complexed PSA (cPSA), and total PSA (tPSA) during the acute phase of the UTI. After 1 month, fPSA rapidly decreased to levels that were maintained during the rest of the follow-up period, and cPSA and tPSA declined more slowly. At 1, 3, and 6 months after the infection the fPSA/tPSA and fPSA/cPSA ratios were abnormal in one half to two thirds of the men (median ratio 11%, 15%, and 16% and 17%, 24%, and 24%, respectively), comparable to findings in patients with prostate cancer.

CONCLUSIONS

These results confirmed that the prostate is involved in men with febrile UTI. The low fPSA/tPSA and fPSA/cPSA ratios in combination with sustained elevations of cPSA and tPSA for up to 6 months after UTI could be falsely interpreted as a sign of prostate cancer. The prolonged elevation of cPSA indicates a long-lasting inflammation of the nonadenomatous parts of the prostate.

Impact of age on total and complexed prostate-specific antigen cutoffs in a contemporary referral series of men with prostate cancer

Age-specific prostate-specific antigen (PSA) cutoffs were previously suggested and were found to miss significant cancers in older men. We assessed the influence of an age-adjusted PSA cutoff to optimize the diagnostic performance (sensitivity and specificity) of complexed PSA (cPSA) and total PSA (tPSA) in the differentiation of benign disease from prostate cancer using a contemporary referral patient cohort. The cPSA and tPSA values were determined using the Bayer Immuno 1 system. The diagnostic utility of tPSA and cPSA was assessed using a diverse contemporary test population consisting of sera prospectively collected between June 1999 and October 2000 from 3597 men who recently underwent a systematic biopsy by urologists in clinical practices throughout the United States. This contemporary patient sample had biopsy diagnoses of either no evidence of malignancy (NEM; N = 2189) or prostate cancer (n = 1408). All serum samples had tPSA values between 2.0 and 20.0 ng/mL. The mean tPSAs (ng/mL) for the NEM and prostate cancer groups were 7.1 +/- 3.2 and 7.3 +/- 3.3, respectively (P = 0.026). The mean cPSAs (ng/mL) for the NEM and prostate cancer groups were 5.6 +/- 2.7 and 6.0 +/- 2.9, respectively (P <0.001). As the tPSA increased from 2.0 to 10.0 ng/mL, the cancer detection rate remained relatively constant at approximately 39% when evaluated using increments of 2.0 ng/mL for tPSA. For fixed sensitivities of 80%, 85%, 90%, and 95%, as the age range increased (45 to 59, 60 to 69, 70 to 79, >or=80), the tPSA and cPSA assay cutoffs required to sustain the specified sensitivity level markedly increased, with the exception of the 95% sensitivity level, where the cutoffs only slightly increased between the age ranges of 45 to 69 and >or=70. Overall, cPSA showed a marginal improvement in specificity versus tPSA across all age groups at all sensitivity levels. In this community referral population, the cancer detection rate remained fairly constant over the tPSA range of 2.0 to 20.0 ng/mL. This study demonstrated that to maintain a given sensitivity level for cPSA and tPSA in the age ranges studied, continuous upward adjustment of the cutoffs was required as age increased.

The impact of intraoperative manipulation of the prostate on total and free prostate-specific antigen

OBJECTIVES

It is well documented that mechanical manipulation of the prostate can elevate total PSA (t-PSA) levels in serum. However, less is known about its effects on free PSA (f-PSA) and the free-to-total PSA ratio (f/t-PSA). We therefore examined the impact of prostate manipulation on t-PSA and f-PSA during surgical procedures involving the prostate.

METHODS

Intraoperative blood samples for t-PSA and f-PSA measurement (Hybritech) were collected every 15 min during 14 radical retropubic prostatectomies (RRP) and 10 radical cystoprostatectomies (RCP).

RESULTS

Prostatic manipulation induced significant elevations in t-PSA and f-PSA during RRP and RCP. Postmanipulatory peaks were markedly higher for f-PSA than for t-PSA. The mean maximum f-PSA levels showed a 4.3- (RRP) and 7.9-fold (RCP) increase, followed by a rapid decline after prostate removal. t-PSA increased 1.2- (RRP) and 1.3-fold (RCP), and declined more slowly. Postmanipulatory f/t-PSA ratios also increased significantly, reaching mean elevations of +0.29 and +0.28 over preoperative ratios during RRP and RCP, respectively.

CONCLUSIONS

Prostate manipulation can induce transient increases in t-PSA, f-PSA and f/t-PSA in benign and malignant prostates. The extent of these alterations and their course over time must be taken into account when postmanipulatory changes in PSA forms are investigated. Timing of postmanipulatory venipunctures and the molar response ratio of t-PSA assays used (equimolar versus nonequimolar) seem to have substantial impact on the results of such studies.

Contemporary use of complexed PSA and calculated percent free PSA for early detection of prostate cancer: impact of changing disease demographics

OBJECTIVES

To assess the diagnostic performance of complexed prostate-specific antigen (cPSA), total PSA (tPSA), and calculated free/total PSA (f/t PSA) ratios in the differentiation of benign disease from prostate cancer (CaP) using a contemporary patient cohort.

METHODS

The cPSA, tPSA, and calculated fPSA values were determined using the Bayer Immuno-1 system. To validate our calculated f/t PSA ratio, we also retrospectively measured fPSA using the Abbott AxSYM immunoassay system in archival pretreatment sera obtained between 1990 and 1997 from 362 men with clinically and biopsy-confirmed benign prostatic hyperplasia (n = 179) or CaP (n = 183). The diagnostic utility of tPSA, cPSA, and the calculated f/t PSA ratio was assessed using a contemporary test population consisting of sera prospectively collected between June 1999 and June 2000 from 3006 men who had recently undergone a systematic biopsy by urologists in clinical practices throughout the United States. This contemporary patient sample had biopsy diagnoses of either no evidence of malignancy (n = 1857) or CaP (n = 1149). All serum samples had tPSA values between 2.0 and 20.0 ng/mL.

RESULTS

The measured versus calculated f/t PSA ratios had a Pearson's correlation coefficient of 0.9130 in the retrospectively studied population of 362 men. The areas under the receiver operating characteristic curves (ROC-AUCs) for the measured and calculated f/t PSA ratios were indistinguishable (69.6% versus 69.2%, respectively). In the contemporary population (n = 3006), the ROC-AUC for tPSA, cPSA, and the calculated f/t PSA ratio was 52.2%, 53.9%, and 58.4%, respectively. We also compared the diagnostic performance using published cutoffs for tPSA (greater than 4.0 ng/mL), cPSA (greater than 3.8 ng/mL), and the f/t PSA ratio (greater than 15% and greater than 25%) in tPSA reflex ranges of 2 to 20 ng/mL and 2 to 10 ng/mL. We found that both cPSA and the f/t PSA ratio (greater than 25% cutoff) outperformed tPSA and yielded similar results in terms of biopsies spared and cancers missed.

CONCLUSIONS

The calculated f/t PSA ratio and cPSA perform equally well in terms of the improvement of specificity in the discrimination of benign disease and CaP. The f/t PSA ratio and cPSA provide clinical benefits over the use of tPSA alone, such as an increased sparing of unnecessary biopsies performed with a manageable degree of risk of delayed cancer detection.

Diagnosis of localized prostate cancer: 10 years of progress

Advances in the diagnosis of early stage disease, and particularly the introduction of prostate-specific antigen (PSA) testing, have had a dramatic effect on the presentation and clinical management of prostate cancer during the past ten years. As a result, there have been significant epidemiological changes in countries where early diagnosis is recommended. The importance of PSA testing for the diagnosis of localized prostate cancer has become well established in clinical practice and this is reflected by improved outcomes from definitive treatment. The contribution of PSA-related parameters and molecular forms of PSA both to cancer detection and prediction of pathological stage continue to be explored. Concerns about the reliability of the standard sextant biopsy technique for cancer detection relate to the need for re-biopsy in a growing number of patients with negative biopsies and an increasing proportion of patients with low volume, multifocal disease. In men with cancer, additional prognostic information can be derived from biopsy findings, with important therapeutic implications. This relates also to the need for reliable markers indicating pathological stage and risk of progression. The opportunities for the prevention of prostate cancer have grown with improved understanding of its biology and the genetic basis of the early steps associated with malignant transformation. In the future, the need for therapeutic intervention is likely to be most influenced by successful prevention strategies.