The prostate specific antigen era in the United States is over for prostate cancer: what happened in the last 20 years?

Prostate-cancer mortality in the USA and UK in 1975-2004: an ecological study

BACKGROUND

There is no conclusive evidence that screening based on serum prostate-specific antigen (PSA) tests decreases prostate-cancer mortality. Since its introduction in the USA around 1990, uptake of PSA testing has been rapid in the USA, but much less common in the UK. Our aim was to study trends over time in prostate-cancer mortality and incidence in the USA and UK in 1975-2004, and compare these patterns with trends in screening and treatment.

METHODS

Joinpoint regression analysis of cancer-mortality statistics from Cancer Research UK (London, UK) and from the US National Cancer Institute Surveillance, Epidemiology and End Results (SEER) programme from 1975 to 2004 was used to estimate the annual percentage change in prostate-cancer mortality in both countries and the points in time when trends changed. The ratio of USA to UK age-adjusted prostate-cancer incidence was also assessed.

FINDINGS

Age-specific and age-adjusted prostate-cancer mortality peaked in the early 1990s at almost identical rates in both countries, but age-adjusted mortality in the USA subsequently declined after 1994 by -4.17% (95% CI -4.34 to -3.99) each year, four-times the rate of decline in the UK after 1992 (-1.14% [-1.44 to -0.84]). The mortality decline in the USA was greatest and most sustained in patients aged 75 years or older (-5.32% [-8.23 to -2.32]), whereas death rates had plateaued in this age group in the UK by 2000. The mean ratio of USA to UK age-adjusted prostate-cancer incidence rates in 1975-2003 was 2.5, with a pronounced peak around the time that PSA testing was introduced in the USA. Numbers needed to treat to prevent one death from prostate cancer were 33 000 in the 55-64-year age group.

INTERPRETATION

The striking decline in prostate-cancer mortality in the USA compared with the UK in 1994-2004 coincided with much higher uptake of PSA screening in the USA. Explanations for the different trends in mortality include the possibility of an early effect of initial screening rounds on men with more aggressive asymptomatic disease in the USA, different approaches to treatment in the two countries, and bias related to the misattribution of cause of death. Speculation over the role of screening will continue until evidence from randomised controlled trials is published.

Detection of early prostate cancer using a hepsin-targeted imaging agent

Early detection and diagnosis of prostate cancer is key to designing effective treatment strategies. Microarrays have resulted in the discovery of hepsin (HPN) as a biomarker for detection of prostate cancer. In this study, we explore the development of HPN imaging probes for detection of prostate cancer. We used phage display to isolate HPN binding peptides with 190 + 2.2 nmol/L affinity in monomeric form and high specificity. The identified peptides were able to detect human prostate cancer on tissue microarrays and in cell-based assays. HPN-targeted imaging agents were synthesized by conjugating multiple peptides to fluorescent nanoparticles to further improve avidity through multivalency and to improve pharmacokinetics. When injected into mouse xenograft models, HPN-targeted nanoparticles bound specifically to HPN-expressing LNCaP xenografts compared with non-HPN-expressing PC3 xenografts. HPN imaging may provide a new method for detection of prostate cancer.

Prostate cancer computer-assisted diagnosis software using dynamic contrast-enhanced MRI

ProCAD is a computer assisted diagnosis (CAD) software dedicated to prostate DCE-MRI analysis.

METHODS

In addition to standard visualization features, 2D and multislice 2D contouring tools based on a seeded growing region algorithm were included in the software. Tumor volume assessment and semiquantitative analysis of suspicious lesions can be performed. A 5-levels cancer suspicion score (ranging from "probably benign" to "Highly suspicious" is calculated on the basis of adjusted parameters extracted from the data of 121 suspicious benign or tumoral lesions.

RESULTS

Using a simple scoring algorithm based the median w.i and w.o values of TZK, TZB, PZK and PZB and designed to provide the highest sensitivity we had respective Se/Sp of 100/49% for peripheral zone cancers, and 100/40% for transition zone cancers characterization.

CONCLUSION

This software provides useful data for an unbiased an reproducible assessment of hypervascularized prostatic areas in routine practice.

The clinical management of patients with a small volume of prostatic cancer on biopsy: what are the risks of progression? A systematic review and meta-analysis

Clinically localized prostate cancer is associated with a wide variation in biologic behavior, and men with the less aggressive form of the disease may never develop symptoms. There has been a rise in prostate cancer incidence in countries in which the blood test for prostatic-specific antigen (PSA) is common, and concerns have been expressed that this may be because of the increased detection of indolent disease, subjecting these men to unnecessary treatment and associated side effects. For the current review, the authors conducted a systematic evaluation of the literature regarding the outcomes of men who were diagnosed on the basis of a small volume of cancer in prostatic biopsies. The results indicated that, despite differences in study design and reporting, a significant proportion of patients with microfocal cancer, regardless of how it was defined, had adverse pathologic findings and a significant risk of PSA recurrence after undergoing radical prostatectomy. Biochemical and clinical recurrences also were observed after radiotherapy or watchful waiting. The authors concluded that patients with microfocal carcinoma on biopsy should be advised that their disease is not necessarily "insignificant" and should be counseled accordingly.

PCA3 molecular urine assay correlates with prostate cancer tumor volume: implication in selecting candidates for active surveillance

PURPOSE

Prostate cancer gene 3 (PCA3) has shown promise as a molecular marker in prostate cancer detection. We assessed the association of urinary PCA3 score with prostatectomy tumor volume and other clinical and pathological features.

MATERIALS AND METHODS

Urine specimens were collected after digital rectal examination from 59 men scheduled for prostate biopsy and 83 men scheduled for radical prostatectomy. Prostatectomy findings were evaluable for 96 men. PCA3 and prostate specific antigen mRNAs were quantified with Gen-Probe DTS 400 System. The PCA3 score was defined as the ratio of PCA3 mRNA/prostate specific antigen mRNA x10(3).

RESULTS

The PCA3 score in men with negative biopsies (30) and positive biopsies (29) were significantly different (median 21.1 and 31.0, respectively, p = 0.029). The PCA3 score was significantly correlated with total tumor volume in prostatectomy specimens (r = 0.269, p = 0.008), and was also associated with prostatectomy Gleason score (6 vs 7 or greater, p = 0.005) but not with other clinical and pathological features. The PCA3 score was significantly different when comparing low volume/low grade cancer (dominant tumor volume less than 0.5 cc, Gleason score 6) and significant cancer (p = 0.007). On multivariate analysis PCA3 was the best predictor of total tumor volume in prostatectomy (p = 0.001). Receiver operating characteristic curve analysis showed that the PCA3 score could discriminate low volume cancer (total tumor volume less than 0.5 cc) well with area under the curve of 0.757.

CONCLUSIONS

The PCA3 score appears to stratify men based on prostatectomy tumor volume and Gleason score, and may have clinical applicability in selecting men who have low volume/low grade cancer.

PSA-related markers in the detection of prostate cancer and high-grade disease in the contemporary era with extended biopsy

OBJECTIVE

To determine the relationship of total PSA (tPSA), percent free PSA (%fPSA), and complexed PSA (cPSA) with prostate cancer detection and the diagnosis of poorly-differentiated cancers in the contemporary era.

METHODS

We retrospectively reviewed the clinical and pathological records of 292 men who met the following inclusion criteria: (1) tPSA 2.5 to 10 ng/ml; (2) initial biopsy only; (3) extended biopsy scheme (>or=10 peripheral zone cores); (4) no previous prostate surgeries. The ability of PSA-related markers to detect cancer was determined by area under the receiver operating characteristics curve analysis (AUC-ROC). Various clinically relevant % fPSA cutoffs and cPSA ranges were analyzed to determine the association with poorly-differentiated cancers.

RESULTS

Cancer was detected in 126 (43%) men, with mean Gleason score of 7. The cancer detection rates for various cutoffs of tPSA, cPSA and % fPSA were very similar. On ROC analysis for cancer diagnosis, the AUCs for tPSA, % fPSA, and cPSA were 0.53, 0.54, and 0.52, respectively. Men with % fPSA <15 were more likely to have poorly-differentiated cancer than those with % fPSA >or=15 (66% vs. 41%, P < 0.005). Similarly, cPSA ranges (2-4, 4.1-6, and >6) were associated with the detection of poorly-differentiated cancers (37%, 57%, and 80% P < 0.003).

CONCLUSIONS

With the use of extended prostate sampling in the contemporary screening population, the addition of cPSA and % fPSA does not enhance the diagnostic performance of tPSA. However, the significant association between cPSA and poorly-differentiated cancers suggests that this may be a more useful initial test for prostate cancer screening.

Electrical impedance spectroscopy of benign and malignant prostatic tissues

PURPOSE

The specificity of current screening methods for prostate cancer is limited and it results in approximately 75% to 80% of patients who undergo biopsy having findings negative for cancer. We used electrical impedance spectroscopy to evaluate how significantly the electrical properties of benign and malignant prostatic tissues differ with the goal of providing clinicians with a new biomarker to aid in diagnosis.

MATERIALS AND METHODS

We collected freshly excised prostates from 14 men immediately following radical prostatectomy. The prostates were sectioned into 3 mm slices. Electrical property measurements of conductivity and relative permittivity were recorded from each slice using a coaxially configured probe over the frequency range of 1 kHz to 1 MHz. The area probed was marked so that following tissue fixation and slide preparation histological assessment could be correlated directly with the recorded electrical impedance spectroscopy spectra.

RESULTS

Prostatic adenocarcinoma, benign prostatic hyperplasia, nonhyperplastic glandular tissue and stroma were the primary tissue types probed with electrical impedance spectroscopy. Conductivity ranged from 0.093 S/m at 1 kHz to 0.277 S/m at 1 MHz. Relative permittivity ranged from 8.5 x 10(5) at 1 kHz down to 1.3 x 10(3) at 1 MHz. There were significant conductivity differences between cancer and stroma at all frequencies (p <0.01). There were significant permittivity differences between cancer and benign prostatic hyperplasia at frequencies greater that 92 kHz (p <0.01). Significant correlations were observed between electrical properties, and the concentration of stromal and glandular tissues present in the tissue area histologically assessed.

CONCLUSIONS

The electrical properties of benign and malignant prostate tissues differ significantly. This should be considered for use as a diagnostic tool. The differences observed between cancer and benign prostatic hyperplasia are especially important since current screening methods do not reliably differentiate between the 2 conditions.

Body composition and serum prostate-specific antigen: review and findings from Flint Men's Health Study

Recent studies have suggested that obesity is associated with lower serum prostate-specific antigen levels, perhaps influencing the recommendation for prostate biopsy and potentially explaining part of the observed poorer prognosis among obese men. African-American men have the greatest rates of prostate cancer and are more likely to die of the disease, making early detection a priority in this group. We present findings from the Flint Men's Health Study, a study of African-American men, that are consistent with most studies suggesting that overweight men have prostate-specific antigen levels that are 0.15 to 0.30 ng/mL lower than those who are not overweight. We have coupled our results with a systematic review of publications in this area.

Residual prostate cancer after radiotherapy: a study of radical cystoprostatectomy specimens

OBJECTIVES

The incidence of histologic prostate cancer (CaP) after definitive radiation therapy (RT) for localized disease is rarely quantitated. We investigated the relationship between prostate-specific antigen (PSA) and histologically residual CaP after definitive RT in patients undergoing radical cystoprostatectomy (RCP) for unrelated indications.

METHODS

We reviewed our prostate cancer database to identify patients undergoing RCP who previously received definitive RT for localized CaP. Pre-radiation variables examined include PSA, Gleason score, radiation modality, and dose. Post-radiation variables reviewed include PSA, time to RCP, the presence of histologically proven prostate cancer, and Gleason score.

RESULTS

We identified 21 patients who underwent RCP at a median of 60 months after RT for localized CaP. Pre-radiation Gleason scores were low (6 or less) to intermediate risk (3+4) in 82% (14 of 17), intermediate (4+3) to high (8 or greater) in 18% (3 of 17), and unavailable in 4 patients. Median pre-radiation PSA was 9 ng/mL. Median PSA before RCP in all patients was 0.8 ng/mL. A total of 52% (11 of 21) of patients demonstrated active CaP in the RCP specimen. Although 89% (16 of 18) of patients met the Phoenix definition of biochemical freedom from disease, 50% (8 of 16) of these patients had histologically residual CaP at the time of RCP. Median PSA was not significantly different between patients with and without active CaP.

CONCLUSIONS

Histologic evidence of CaP was noted in 50% of patients demonstrating biochemical freedom from disease at the time of RCP. Although the biological significance of active CaP in this select population is uncertain, our findings demonstrate the limitations of PSA in monitoring CaP disease activity after definitive RT.

Radical prostatectomy for incidental (stage T1a-T1b) prostate cancer: analysis of predictors for residual disease and biochemical recurrence

BACKGROUND

Controversies exist about the most appropriate management for patients with incidental prostate cancer after surgery for benign prostatic hyperplasia (BPH).

OBJECTIVES

To test the accuracy of preoperative clinical variables in predicting the presence of residual disease and biochemical recurrence in patients with incidental prostate cancer treated with radical retropubic prostatectomy.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed 126 T1a-T1b prostate cancers diagnosed at surgery for BPH between 1995 and 2007.

INTERVENTION

All patients underwent radical retropubic prostatectomy within 6 mo of surgery for BPH.

MEASUREMENTS

Univariate and multivariate logistic regression models addressed the association between the predictors (age, prostate-specific antigen [PSA] before and after surgery for BPH, T1a-T1b stage, prostate volume, and Gleason score at surgery for BPH) and the presence of residual cancer at radical retropubic prostatectomy. Cox proportional hazards regression analyses tested the relationship between the same predictors and the rate of biochemical recurrence after radical retropubic prostatectomy.

RESULTS AND LIMITATIONS

Seventy-five (59.5%) patients were stage T1a and 51 (40.5%) were stage T1b. At radical retropubic prostatectomy, 21 (16.7%) patients were pT0 and seven (5.6%) patients had extraprostatic disease (pT3). PSA before and after surgery for BPH and Gleason score at surgery for BPH were the only independent predictors of residual cancer at radical retropubic prostatectomy (all p<0.04). Stage (T1a vs T1b) did not predict residual cancer or the rate of biochemical recurrence. With a mean follow-up of 57 mo, the 5- and 10-yr biochemical recurrence-free survival rates were 92% and 87%, respectively. PSA after surgery for BPH and Gleason score at surgery for BPH were the only significant multivariate predictors of biochemical recurrence (all p<0.04). The main limitation of this study is the requirement of an external validation before implementation of the clinical recommendations.

CONCLUSION

PSA measured before and after surgery for BPH and Gleason score at surgery for BPH were the only significant predictors of the presence of residual cancer at radical retropubic prostatectomy. PSA measured after surgery for BPH and Gleason score at surgery for BPH were the only independent predictors of biochemical recurrence after radical retropubic prostatectomy.

Serum markers for prostate cancer: a rational approach to the literature

INTRODUCTION

Due to its universal applicability for early detection and prediction of cancer stage and disease recurrence, widespread implementation of serum-based prostate-specific antigen (PSA) measurements has a significant influence on current treatment strategies for men with prostate cancer (PCa). However, over-detection and the resultant over-treatment of indolent cancers have been strongly implicated to occur. Using current recommended guidelines, the PSA test suffers from both limited sensitivity and specificity to enable efficacious population-based cancer detection. Therefore, novel biomarkers are much needed to complement PSA by enhancing its diagnostic and prognostic performance.

METHODS

The present literature on serum markers for PCa was reviewed. PSA derivatives, molecular PSA isoforms, and novel molecular targets in blood were summarized and weighted against their potential to improve decision-making of men with PCa.

RESULTS

Current evidence suggests that no single analyte is likely to achieve the desired level of diagnostic and prognostic accuracy for PCa. However, the combination of biomarkers with clinical and demographic data, for example, using established standard nomograms, has produced progress toward the goal of both optimal screening and risk assessment. Furthermore, potential candidate molecular markers for PCa can be derived from high-throughput technologies. Current studies demonstrate that understanding dynamic PSA changes over time may offer diagnostic and prognostic information.

CONCLUSIONS

Bridging the gap between basic science and clinical practice represents the main goal in the near future to enable physicians to tailor risk-adjusted screening and treatment strategies for current patients with PCa.

Promoter hypermethylation in circulating blood cells identifies prostate cancer progression

Promoter hypermethylation of circulating cell DNA has been advocated as a diagnostic marker for prostate cancer, but its prognostic use is currently unclear. To assess this role, we compared hypermethylation of circulating cell DNA from prostate cancer patients with (Group 1, n = 20) and without (Group 2, n = 22) disease progression and age-matched controls (benign prostatic hyperplasia, Group 3, n = 22). We measured hypermethylation of 10 gene promoters in 2 sequential venous samples, obtained at diagnosis and during disease progression (median time, 15 months later). Matched time samples were obtained in the nonprogressing patients. We found that more hypermethylation was detected in the diagnostic sample from the patients with cancer than in controls for GSTP1, RASSF1 alpha, APC and RAR beta (p < 0.0001). Patients undergoing disease progression had a significant increase in methylation levels of these 4 genes when compared to the other patients (p < 0.001). Patients at risk of disease progression have higher detectable concentrations of circulating cell hypermethylation, than those without progression. The extent of this hypermethylation increases during disease progression and can be used to identify the extent and duration of treatment response in prostate cancer.

Secular trends in prostate cancer mortality, incidence and treatment: England and Wales, 1975-2004

OBJECTIVE

To aid the interpretation of the trends in prostate cancer mortality, which declined in the UK in the early 1990 s for unknown reasons, by investigating prostate cancer death rates, incidence and treatments in England and Wales in 1975-2004.

METHODS

Join-point regression was used to assess secular trends in mortality and incidence (source: Office of National Statistics), radical prostatectomy and orchidectomy (source: Hospital Episode Statistics database) and androgen-suppression drugs (source: Intercontinental Medical Statistics).

RESULTS

Prostate cancer mortality declined from 1992 (95% confidence interval, CI, 1990-94). The relative decline in mortality to 2004 was greater and more sustained amongst men aged 55-74 years (annual percentage mortality reduction 2.75%; 95% CI 2.33-3.18%) than amongst those aged >or=75 years (0.71%, 0.26-1.15%). The use of radical prostatectomy increased between 1991 (89 operations) and 2004 (2788) amongst men aged 55-74 years. The prescribing of androgen suppression increased between 1987 (33,000 prescriptions) and 2004 (470,000).

CONCLUSIONS

The decrease in prostate cancer mortality was greater amongst men aged 55-74 years than in those aged >or=75 years, but pre-dated the substantial use of prostate-specific antigen screening and radical prostatectomy in the UK. An increase in radical therapy amongst younger groups with localized cancers and screen-detected low-volume locally advanced disease as a result of stage migration, as well as prolonged survival from increased medical androgen suppression therapy, might partly explain recent trends.

Why men in the United Kingdom still want the prostate specific antigen test

The prostate specific antigen (PSA) test is widely used to screen men for prostate cancer, but its value in diagnosing prostate cancer in asymptomatic men is controversial. In 2001, the U.K. Department of Health introduced the Prostate Cancer Risk Management Programme (PCRMP), through which men are given relatively detailed information before they make a final decision about a test. Little is known about men's experiences of the test since this program was introduced. We report an analysis of interviews with 30 men who were tested, or considered having a test, since the PCRMP was introduced. Our analysis suggests that men's views of the PSA test are dominated by their construction of testing as responsible health behavior and their perception of PSA as "just a blood test." Men's accounts also suggest that poor communication about the uncertainty of the test--and about treatment for prostate cancer--also persists.

[A study of the progression of the incidental prostate cancer depending on the kind of treatment performed]

INTRODUCTION AND OBJECTIVES

Prostate cancer is a common neoplasm, with a significant burden of mortality. Since it's diagnosed at old ages and usually growths slowly, agresive treatment of localised cancer of prostate could be of little benefit. The study of the evolution of incidental prostate cancer diagnosed 20 years ago could give directions for present decision-making.

METHODS

We performed a time survival analysis of patients diagnosed of incidental prostate cancer between 1980 and 2000, and followed them until april 2005. We analysed overall and disease-specific mortality, related to the kind of treatment and some anatomopathological characteristics.

RESULTS

We included 80 cases. Treatment was hormonotherapy in 34 cases, surgery in 4, radiotherapy in 3 and watchful waiting in 39. Overall average survival was 8.87 years. Disease-specific survival in low risk group (Gleason lower than 6) was 16 years, and in high risk group (Gleason higher than 7) was 6 years. No differences were found between hormonotherapy and watchful waiting.

CONCLUSIONS

While in low risk patients watchful waiting represents an acceptable aproaching, it could not be adequate in high risk cases. Hormonotherapy showed no benefit in incidental prostate cancer.

Epigenetic targets in the diagnosis and treatment of prostate cancer

Prostate cancer (PC) is one of leading cause of cancer related deaths in men. Various aspects of cancer epigenetics are rapidly evolving and the role of 2 major epigenetic changes including DNA methylation and histone modifications in prostate cancer is being studied widely. The epigenetic changes are early event in the cancer development and are reversible. Novel epigenetic markers are being studied, which have the potential as sensitive diagnostic and prognostic marker. Variety of drugs targeting epigenetic changes are being studied, which can be effective individually or in combination with other conventional drugs in PC treatment. In this review, we discuss epigenetic changes associated with PC and their potential diagnostic and therapeutic applications including future areas of research.

Validation of the contemporary epstein criteria for insignificant prostate cancer in European men

OBJECTIVES

The Epstein criteria represent the most widely used scheme for prediction of clinically insignificant prostate cancer (PCa). However, they were never validated in European men. We assessed the rate of unfavorable prostate cancer (Gleason 7-10 or non-organ-confined disease) in a cohort of 366 men who fulfilled the Epstein clinically insignificant PCa criteria.

METHODS

Between 1996 and 2006, 2580 men underwent radical prostatectomy at a single academic European institution. Of those, 366 fulfilled the contemporary Epstein clinically insignificant PCa criteria. Analyses targeted the rate of pathologically unfavorable prostate cancer, defined as either Gleason sum 7-10 or non-organ-confined disease, or a combination of these characteristics in patients with clinically insignificant PCa.

RESULTS

Gleason 7-10 prostate cancer at radical prostatectomy was found in 88 patients (24%) with clinically insignificant PCa. In addition, 30 (34.1%) of the 88 patients harboured non-organ-confined disease. Consequently, the contemporary Epstein criteria for clinically insignificant PCa were inaccurate in 24% of patients.

CONCLUSIONS

The Epstein clinical insignificant PCa criteria may underestimate the true nature of prostate cancer in as many as 24% of European patients. Therefore, caution is advised when treatment decisions are based solely on these criteria.

Comparison of cancers detected at only a sextant or alternative location

OBJECTIVES

To evaluate the effect of the tumour-positive biopsy site at extended biopsy on tumour volume and potential biological significance of prostate cancer.

PATIENTS AND METHODS

We retrospectively evaluated radical prostatectomy specimens from 247 consecutive men diagnosed with prostate cancer by extended biopsy. Men who had both a positive sextant and alternative site were excluded, resulting in 132 evaluable men. We assessed age, pretreatment prostate-specific antigen (PSA) level, prostate volume, pathological stage, Gleason score, total tumour volume, and location (sextant or alternative site) of the positive biopsy. Patients were grouped by location of the positive biopsy, i.e. sextant site only or alternative site only, including anterior horn, midline region and transition zone.

RESULTS

A biopsy from a sextant-only or an alternative site only was positive in 42% (56/132) and 58% (76/132) of men, respectively. There was no significant difference in PSA level, number of positive cores, pathological stage, Gleason score, total tumour volume or the incidence of low-volume/low-grade cancer (volume <0.5 mL and a Gleason score of </=6) between the groups. In men with one positive core, there was no significant difference in total tumour volume (median 0.20 vs 0.36 mL, respectively) or in the incidence of low-volume/low-grade cancer (42% vs 40%, respectively) between the groups.

CONCLUSIONS

Total tumour volume and the incidence of low-volume/low-grade cancer detected at an alternative site only were comparable to those of cancers detected at a sextant site only. Alternative site biopsy did not increase the incidence of low-volume/low-grade cancers detected.

Discrimination of prostate cancer cells and non-malignant cells using secondary ion mass spectrometry

This communication utilises Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) combined with multivariate analysis to obtain spectra from the surfaces of three closely related cell lines allowing their discrimination based upon mass spectral ions.

New circulating biomarkers for prostate cancer

The introduction of prostate-specific antigen (PSA) revolutionized prostate cancer (PCa) screening and ushered the PSA era. However, its use as a screening tool remains controversial and changes in the epidemiology of PCa have strongly limited its prognostic role. Therefore, we need novel approaches to improve our ability to detect PCa and foretell the course of the disease. To improve the specificity of total PSA, several approaches based on PSA derivatives have been investigated such as age-specific values, PSA density (PSAD), PSAD of the transition zone, PSA velocity and assessment of various isoforms of PSA. With recent advances in biotechnology such as high-throughput molecular analyses, many potential blood biomarkers have been identified and are currently under investigation. Given the plethora of candidate PCa biomarkers, we have chosen to discuss a select group of candidate blood-based biomarkers including human glandular kallikrein, early prostate cancer antigens, insulin-like growth factor-I (IGF-I) and its binding proteins (IGFBP-2 and IGFBP-3), urokinase plasminogen activation system, transforming growth factor-beta1, interleukin-6, chromogranin A, prostate secretory protein, prostate-specific membrane antigen, PCa-specific autoantibodies and alpha-methylacyl-CoA racemase. While these and other markers have shown promise in early phase studies, no single biomarker is likely to have the appropriate degree of certainty to dictate treatment decisions. Consequently, the future of cancer prognosis may rely on small panels of markers that can accurately predict PCa presence, stage, metastasis, and serve as prognosticators, targets and/or surrogate end points of disease progression and response to therapy.

Focal therapy for localized prostate cancer: a critical appraisal of rationale and modalities

PURPOSE

Based on contemporary epidemiological and pathological characteristics of prostate cancer we explain the rationale for and concerns about focal therapy for low risk prostate cancer, review potential methods of delivery and propose study design parameters.

MATERIALS AND METHODS

Articles regarding the epidemiology, diagnosis, imaging, treatment and pathology of localized prostate cancer were reviewed with a particular emphasis on technologies applicable for focal therapy, defined as targeted ablation of a limited area of the prostate expected to contain the dominant or only focus of cancer. A consensus summary was constructed by a multidisciplinary international task force of prostate cancer experts, forming the basis of the current review.

RESULTS

In regions with a high prevalence of prostate specific antigen screening the over detection and subsequent overtreatment of prostate cancer is common. The incidence of unifocal cancers in radical prostatectomy specimens is 13% to 38%. In many others there is an index lesion with secondary foci containing pathological features similar to those found incidentally at autopsy. Because biopsy strategies and imaging techniques can provide more precise tumor localization and characterization, there is growing interest in focal therapy targeting unifocal or biologically unifocal tumors. The major arguments against focal therapy are multifocality, limited accuracy of staging, the unpredictable aggressiveness of secondary foci and the lack of established technology for focal ablation. Emerging technologies with the potential for focal therapy include high intensity focused ultrasound, cryotherapy, radio frequency ablation and photodynamic therapy.

CONCLUSIONS

Early detection of prostate cancer has led to concerns that while many cancers now diagnosed pose too little a threat for radical therapy, many men are reluctant to accept watchful waiting or active surveillance. Several emerging technologies seem capable of focal destruction of prostate tissue with minimal morbidity. We encourage the investigation of focal therapy in select men with low risk prostate cancer in prospective clinical trials that carefully document safety, functional outcomes and cancer control.

Prostate-Specific Antigen Improves the Ability of Clinical Stage and Biopsy Gleason Sum to Predict the Pathologic Stage at Radical Prostatectomy in the New Millennium

OBJECTIVES

The contemporary ability of prostate-specific antigen (PSA) to predict pathologic stage in men with localized prostate cancer was recently questioned.

METHODS

We quantified the added value related to the addition of pretreatment PSA to established pathologic stage predictors (namely clinical stage and biopsy Gleason sum) in 5921 consecutive radical prostatectomy (RP) patients. Univariable and multivariable logistic regression analyses predicting pathologic stage (extracapsular extension [ECE], seminal vesicle invasion [SVI], lymph node invasion [LNI], and organ-confined disease [OC]) were stratified according to four time quartiles. The gain in predictive accuracy (PA) related to the inclusion of PSA to multivariable models was quantified by using the area under the curve method.

RESULTS

Temporal analyses showed a decrease in PSA levels over the study years (p<0.001). Conversely, the rate of nonpalpable disease and the rate of biopsy Gleason sum < or =6 increased over time (all p<0.001). At RP, the rate of OC increased over time, while the rate of ECE and SVI decreased over time (all p<0.001). The rate of LNI remained stable (p=0.1). In multivariable models, PSA represented an independent predictor of all pathologic stages over time (all p<0.03), except for ECE in the first and last time quartiles. The addition of PSA significantly increased the multivariable PA of all models predicting pathologic stages over time (all p<0.03), except for ECE predictions in the first quartile (p=0.1).

CONCLUSIONS

In the new millennium, PSA has not lost its ability to accurately predict the pathologic stage in contemporary patients.

Assessing individual risk for prostate cancer

PURPOSE

To construct a clinical nomogram instrument to estimate individual risk for having prostate cancer (PC) for patients undergoing prostate specific antigen (PSA) screening, using all risk factors known for PC.

PATIENTS AND METHODS

We conducted a cross-sectional study of 3,108 men who underwent a prostate biopsy, including a subset of 408 volunteers with normal PSA levels. Factors including age, family history of PC (FHPC), ethnicity, urinary symptoms, PSA, free:total PSA ratio, and digital rectal examination (DRE) were incorporated in the model. A nomogram was constructed to assess risk for any and high-grade PC (Gleason score >or= 7).

RESULTS

Of the 3,108 men, 1,304 (42.0%) were found to have PC. Among the 408 men with a normal PSA (< 4.0 ng/mL), 99 (24.3%) had PC. All risk factors were important predictors for PC by multivariate analysis (P, .01 to .0001). The area under the curve (AUC) for the nomogram in predicting cancer, which included age, ethnicity, FHPC, urinary symptoms, free:total PSA ratio, PSA, and DRE, was 0.74 (95% CI, 0.71 to 0.81) and 0.77 (95% CI, 0.74 to 0.81) for high-grade cancer. This was significantly greater than the AUC that considered using the conventional screening method of PSA and DRE only (0.62; 95% CI, 0.58 to 0.66 for any cancer; 0.69; 95% CI, 0.65 to 0.73 for high-grade cancer). From receiver operating characteristic analysis, risk factors including age, ethnicity, FHPC, symptoms, and free:total PSA ratio contributed significantly more predictive information than PSA and DRE.

CONCLUSION

In a PC screening program, it is important to consider age, family history of PC, ethnicity, urinary voiding symptoms, and free:total PSA ratio, in addition to PSA and DRE.

Clinicopathologic Features of Prostate Adenocarcinoma Incidentally Discovered at the Time of Radical Cystectomy: An Evidence-Based Analysis

OBJECTIVES

To review all relevant features of incidentally discovered prostate cancer (PCa) in patients undergoing radical cystectomy for bladder cancer: incidence, pathologic characteristics, clinical significance, and implications for its management.

METHODS

A structured literature review through a MEDLINE search was performed.

RESULTS

The frequency of incidentally discovered PCa in cystoprostatectomy specimens is extremely variable because of several factors, particularly the pathology sampling. The relationship among clinically, incidentally, and autopsy-detected cancer is uncertain. The definition of clinically significant cancer varies among published reports and remains inadequate for clinical application. High-grade prostatic intraepithelial neoplasia is a marker for concurrent PCa and the risk depends more on the volume than on its absolute presence. Outcome of patients with unsuspected PCa after cystoprostatectomy relies mostly on the bladder tumor.

CONCLUSIONS

Incidental PCa in patients with bladder cancer is highly variable and with an unclear clinical significance. For those who are candidates for prostate-sparing surgery, it seems reasonable to include a routine prostate biopsy in the standard preoperative work-up irrespective of prostate-specific antigen values. In the absence of sufficient data to make firm recommendations, when PCa is incidentally discovered, PCa surveillance should be part of the follow-up scheme after radical cystectomy.

Prostate-specific antigen density predicts adverse pathology and increased risk of biochemical failure

OBJECTIVES

To determine whether the prostate-specific antigen (PSA) density (PSAD), measured using either ultrasound (US) or prostatic weight (PW), is an independent predictor of adverse pathologic findings or biochemical-free survival and whether it outperformed PSA.

METHODS

The data were obtained prospectively from 1327 patients undergoing radical prostatectomy from 1990 to 2003. The US PSAD was calculated by dividing the preoperative PSA level in nanograms per milliliter by the US measured prostate volume in cubic centimeters. The PW PSAD was calculated by dividing the PSA value in nanograms per milliliter by the measured PW of the prostatectomy specimen in grams. Logistic regression analysis was performed to determine whether the US or PW PSAD was more accurate than the PSA level in predicting for adverse pathologic findings. A proportional hazards model was used to determine whether PSAD more accurately predicted for biochemical failure (PSA level greater 0.2 ng/mL).

RESULTS

Multivariate analysis demonstrated that US and PW PSAD were independent predictors of positive margins (odds ratio [OR] 5.00, 95% confidence interval [CI] 2.65 to 9.47 and OR 29.75, 95% CI 10.18 to 86.96, respectively), extracapsular disease (OR 10.89, 95% CI 5.32 to 22.32 and OR 126.62, 95% CI 37.99 to 422.07, respectively), seminal vesical invasion (OR 6.06, 95% CI 2.96 to 12.41 and OR 33.72, 95% CI 9.79 to 116.15, respectively), and biochemical failure (hazard ratio 3.32, 95% CI 2.38 to 4.63 and hazard ratio 8.70, 95% CI 5.21 to 14.52, respectively). The C-index demonstrated that both US and PW PSAD appeared more discriminant for adverse pathologic findings and biochemical failure than did the PSA level.

CONCLUSIONS

The US and PW PSAD are strong predictors of advanced pathologic features and biochemical failure after radical prostatectomy. The incorporation of PSAD into the risk assessment could provide additional prognostic information beyond grade, stage, and PSA level; therefore, the inclusion of PSAD into nomograms should be considered.

Screening for prostate cancer: an update

OBJECTIVES

To review evidence regarding the potential introduction of prostate cancer screening programmes and highlight issues pertinent to the management of screen-detected prostate cancer.

METHODS

Screening for prostate cancer is a controversial health care issue in general and urological practice. A PubMed database search was performed, followed by a systematic review of the literature, to examine the evidence base underlying prostate cancer screening.

RESULTS

A prostate cancer screening programme should satisfy several key postulates prior to its introduction. To date, several of these postulates have not been satisfied, and the evidence available for prostate cancer screening is currently insufficient to warrant its introduction as a public health policy. The natural history of screen-detected prostate cancer remains poorly understood, and recent evidence suggests that a screening programme may detect a large number of men with indolent disease who may be subsequently overtreated. Several randomised clinical trials are currently in progress and it is hoped that they will provide robust evidence to inform future practice.

CONCLUSIONS

National systematic prostate cancer screening programmes outside randomised clinical trial settings have not been implemented to date owing to lack of robust evidence that such programmes would improve survival and/or quality of life in men with screen-detected disease. Forthcoming results of clinical trials and the application of appropriate risk stratification to prevent overtreatment of indolent prostate cancer are likely to change practice in coming years.

Proteomics in clinical prostate research

The incidence of early prostate cancer (PCa) has increased rapidly in recent years. The majority of newly diagnosed PCa are in early tumor phase. Presently, we do not have adequate biomarkers to assess tumor aggressiveness in individual cases. Consequently, too many patients are given curatively intended treatment. An exploration of the human proteome may provide clinically useful markers. 2-DE has been successfully used for analysis of the protein phenotype using clinical samples. Proteins are separated according to size and charge, gels are compared by image analysis, protein spots of interest are excised, and proteins identified by MS. This method is exploratory and allows protein identification. However, low-abundance proteins are difficult to detect and 2-DE is currently too labor-intensive for routine use. In recent years, nongel based techniques, such as LC-MS, SELDI-MS, and protein arrays have emerged. They require smaller sample sizes and can be more automated than 2-DE. In this review, we describe studies of the protein expression of benign prostatic tissue and PCa, which is likely to serve as the first step in prognostic biomarker discovery. The prostate proteome is still far from a complete mapping which would enhance our understanding of PCa biology.

Collagen XXIII expression is associated with prostate cancer recurrence and distant metastases

PURPOSE

We had previously identified a new transmembrane collagen, type XXIII, in metastatic rat prostate carcinoma cells. The purpose of this study was to determine the expression of collagen XXIII in human prostate cancer and investigate its relationship with disease progression.

EXPERIMENTAL DESIGN

We investigated collagen XXIII expression in prostate cancer tissue and did a retrospective analysis of association with prostate-specific antigen (PSA)-defined disease recurrence. The presence of collagen XXIII in prostate cancer patient urine was also assessed before and after prostatectomy.

RESULTS

Collagen XXIII protein was detected at very low levels in benign prostate tissue and was significantly increased in prostate cancer. Distant metastases exhibited significantly higher collagen XXIII levels compared with either localized prostate cancer or regional (lymph node) metastases. Patients with high collagen XXIII levels had a 2.8-fold higher risk of PSA failure with median time to failure of 8.1 months, compared with low collagen XXIII patients with a median time to failure of 5 years. Multivariate Cox regression showed that the presence of collagen XXIII was significantly associated with time to PSA recurrence, independent of other clinical variables. Collagen XXIII was also detected in prostate cancer patient urine, with reduced levels after prostatectomy, indicating potential as a noninvasive fluid biomarker.

CONCLUSIONS

We present the first report demonstrating increased collagen XXIII expression in prostate cancer tissue. We show that collagen XXIII level is a significant independent predictor of PSA-defined disease recurrence, suggesting a potential role as a molecular biomarker of prostate cancer progression and metastasis.

Electrical Impedance Spectroscopy of the Human Prostate

Tissue electrical impedance is a function of its architecture and has been used to differentiate normal and cancer tissues in a variety of organs including breast, cervix, skin, and bladder. This paper investigates the possibility of differentiating normal and malignant prostate tissue using bioimpedance spectra. A probe was designed to measure impedance spectra over the range of 10 kHz to 1 MHz. The probe was fully characterized using discrete loads and saline solutions of different concentrations. Impedance spectra of five ex vivo prostates were measured in the operating room immediately following radical prostatectomy. Wilcoxon signed-rank tests were used to compare the normal and malignant findings. The impedance probe had a signal-to-noise ratio (SNR) > 84 dB across the entire spectrum and measured a tissue volume of approximately 46 mm(3). At 10 kHz, prostate conductivity (or) ranged from 0.232 S/m to 0.310 S/m for tumor and from 0.238 S/m to 0.901 S/m for normal tissue. At 1 MHz the ranges were 0.301 S/m to 0.488 S/m for tumor and 0.337 S/m to 1.149 S/m for normal. Prostate permittivity (epsilonr) ranged from 6.64 x10(4) to 1.25 x 10(5) for tumor and from 9.08 x 10(4) to 4.49 x 10(5) for normal tissues at 10 kHz. And, at 1 MHz the er ranges were 9.23 x 10(2) to 1.88 x 10(3) for tumor and 1.16 x 10(3) to 2.18 x 10(3) for normal tissue. Both sigma and epsilonr of tumor tissue were found to be significantly lower than that of normal tissue (P < 0.0001). Conductivity and permittivity are both higher in normal prostate tissues than they are in malignant tissue making them suitable parameters for tissue differentiation. This is in agreement with trends observed in other tissues reported in much of the literature. Expanded studies are needed to further validate this finding and to explore the biological mechanism responsible for generating the results.

The PSA testing dilemma: GPs' reports of consultations with asymptomatic men: a qualitative study

BACKGROUND

The National Health Service Prostate Cancer Risk Management Programme (PCRMP) has recommended that screening for prostate cancer is available for asymptomatic men, on the understanding that they have been provided with full and balanced information about the advantages and limitations of the prostate-specific antigen (PSA) test. Guidance has been distributed to all GPs in England and Wales to assist in the provision of information to men. This study aimed to elicit GPs' accounts of their discussions with asymptomatic men who consult with concerns about prostate cancer in order to identify the degree to which the PCRMP guidance was reflected in these consultations.

METHODS

Qualitative interview study. Semi-structured telephone interviews with 21 GPs from 18 GP practices in Oxfordshire.

RESULTS

All GPs reported undertaking some discussion with asymptomatic men about the PSA test. They described focussing most of the discussion on the false-positive and false-negative rates of the test, and the risks associated with a prostate biopsy. They reported less discussion of the potential for diagnosing indolent cancers, the dilemmas regarding treatment options for localised prostate cancer and the potential benefits of testing. Considerable variation existed between GPs in their accounts of the degree of detail given, and GP's presentation of information appeared to be affected by their personal views of the PSA test.

CONCLUSION

The GPs in this study appear to recognise the importance of discussions regarding PSA testing; however, a full and balanced picture of the associated advantages and limitations does not seem to be consistently conveyed. Factors specific to PSA testing which appeared to have an impact on the GPs' discussions were the GP's personal opinions of the PSA test, and the need to counter men's primarily positive views of the benefits of PSA testing. Awareness of the impact of their views on the consultations may help GPs give men a more balanced presentation of the benefits and limitations of the PSA test.

Prevalence and Clinical Significance of Prostate Cancer among 12,682 Men with Normal Digital Rectal Examination, Low PSA Levels (≤4 ng/ml) and Percent Free PSA Cutoff Values of 15 and 20%

AIM

To report prevalence and clinical relevance of T1c prostate cancers (PCa) in a selected population of men with serum prostate-specific antigen (PSA) levels < or =4 ng/ml enrolled in a multicenter case-finding protocol.

PATIENTS AND METHODS

A number of 16,298 men, aged 40-75 years, from the urology units they had been referred to, in most cases (81.6%) for lower urinary tract symptoms, were evaluated. Eighty percent of them had PSA < or =4 ng/ml and about 40% PSA < or =2.5 ng/ml. Patients with PSA < or =2.5 ng/ml and PSA between 2.6 and 4 ng/ml and with percent free PSA < or =15 and < or =20%, respectively, were eligible for biopsy; 28 patients refused it, and 11 patients were excluded from the study because of an abnormal digital rectal examination. Among 403 biopsied men, 82 had PSA < or =2.5 ng/ml (group A) and 321 PSA between 2.6 and 4 ng/ml (group B).

RESULTS

A PCa was found in 109 cases (27.0%): 21 in group A and 88 in group B. 48 (44%) of the 109 patients with a PCa underwent radical prostatectomy: all cancers had a volume >0.5 cm(3), and 41% had a final Gleason sum > or =7; the PCa was organ confined in 34 patients (70.8%) and locally advanced in 14 patients (29.1%), and in 12 patients (25%) positive surgical margins were found.

CONCLUSIONS

Using percent free PSA thresholds of 15 and 20%, 25.6% of the men with PSA < or =2.5 ng/ml and 27.4% of the men with PSA between 2.6 and 4 ng/ml were found to have a PCa, respectively. Most of these cancers, when submitted to radical prostatectomy, were found to be clinically significant. As these cancers are mostly organ confined, these patients are ideal candidates for curative nerve-sparing surgery.

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.