Review of diagnostic markers for prostate cancer

The role of proteomics in the multiplexed analysis of gene alterations in human cancer

INTRODUCTION

Proteomics has played a pivotal role in identifying proteins perturbed in disease conditions when compared with healthy samples. Study of dysregulated proteins aids in identifying diagnostic markers and potential therapeutic targets. Cancer is an outcome of interplay of several such disarrayed proteins and molecular pathways which perturb cellular homeostasis, resulting in transformation. In this review, we discuss various facets of proteomic approaches, including tools and technological advancements, aiding in understanding differentially expressed molecules and signaling mechanisms.

AREAS COVERED

In this review, we have taken the approach of documenting the different methods of proteomic studies, ranging from labeling techniques, data analysis methods, and the nature of molecule detected. We summarize each technique and provide a glimpse of cancer research carried out using them, highlighting the advantages and drawbacks in comparison with others. Literature search using online resources, such as PubMed and Google Scholar were carried out for this approach.

EXPERT OPINION

Technological advancements in proteomics studies have come a long way from the study of two-dimensional mapping of proteins separated on gels in the early 1970s. Higher precision in molecular identification and quantification (high throughput), and greater number of samples analyzed have been the focus of researchers.

Efficacy and safety of dutasteride compared with finasteride in treating males with benign prostatic hyperplasia: A meta-analysis of randomized controlled trials

The present study was an updated meta-analysis that aimed to confirm the efficacy and safety of dutasteride (0.5 mg) and finasteride (5 mg) in treating males with benign prostatic hyperplasia (BPH) over a treatment period of at least 6 months. Randomized controlled trials were retrieved using the MEDLINE, EMBASE and the Cochrane controlled trials register databases. The references of the associated articles were also searched. A systematic review was performed by using the preferred reporting items for systematic reviews and meta-analyses. The data were analyzed with RevMan v5.3.0. A total of six articles including 2,041 participants were studied. The analysis demonstrated a significantly greater decrease in international prostate symptom score [IPSS; mean difference (MD), -0.86; 95% CI, -1.62 to -0.11; P=0.02] and prostate-specific antigen (PSA; MD, -0.13; 95% CI, -0.26 to -0.01; P=0.03) in the dutasteride group compared with that in the finasteride group, whereas no significant differences were observed in prostate volume (PV; P=0.64), maximum urine flow rate (Qmax; P=0.29) and post-void residual volume (PVRV; P=0.14). With regard to safety assessment, including any adverse event (P=0.66), decreased libido (P=0.39) and impotence (P=0.17), there was no significant difference between dutasteride and finasteride. In conclusion, in patients with BPH, dutasteride produced a greater decrease in IPSS and PSA compared with finasteride, whereas no significant differences were identified in PV, Qmax and PVRV. The two drugs appeared to have similar rates of adverse effects, particularly with regard to sexual dysfunction.

Meta-analysis of the efficacy and safety of combination of tamsulosin plus dutasteride compared with tamsulosin monotherapy in treating benign prostatic hyperplasia

Background

We performed a meta-analysis to confirm the efficacy and safety of the combination of tamsulosin plus dutasteride compared with tamsulosin monotherapy in treating benign prostatic hyperplasia (BPH) during a treatment cycle of at least 1 year.

Methods

Randomized controlled trials were searched by using MEDLINE, EMBASE, and the Cochrane Controlled Trials Register. Systematic review was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-analyses. The data was evaluated and statistically analyzed by using RevMan version 5.3.0.

Results

Five studies including 4348 patients were studied. The analysis found that the combination group was significantly greater effect in international prostate symptom score (mean difference [MD], − 1.43; 95% confidence interval [CI], − 2.20 to − 0.66; P = 0.0003), prostate volume (MD, − 10.13; 95% CI, − 12.38 to − 7.88; P < 0.00001), transitional zone volume (MD, − 3.18; 95% CI, − 3.57 to − 2.79; P<0.0001), maximum urine flow rate (MD, 1.05; 95% CI, 0.82 to 1.29; P < 0.00001), prostate specific antigen (MD, − 0.54; 95% CI, − 0.80 to − 0.29; P < 0.0001) and post-void residual volume (MD, − 3.85; 95% CI, − 4.95 to − 2.76; P < 0.00001) compared with the tamsulosin group. In terms of safety, including adverse events (odds ratio [OR], 2.06; 95% CI, 1.34 to 3.17; P = 0.001), erectile dysfunction (OR, 2.24; 95% CI, 1.73 to 2.92; P < 0.00001), ejaculation disorder (OR, 3.37; 95% CI, 1.97 to 5.79; P < 0.0001), retrograde ejaculation (OR, 2.30; 95% CI, 1.08 to 4.93; P = 0.03), decreased libido (OR, 2.25; 95% CI, 1.53 to 3.31; P < 0.0001) and loss of libido (OR, 3.38; 95% CI, 1.94 to 5.88; P<0.0001), the combination group showed poor tolerance than the tamsulosin group with the exception of dizziness (OR, 1.16; 95% CI, 0.75 to 1.80; P = 0.50). The combination group significantly reduced the risk of clinical progression than the tamsulosin group especially in incidence of BPH-related symptom progression (OR, 0.56; 95% CI, 0.46 to 0.67; P < 0.00001) and acute urinary retention (OR, 0.61; 95% CI, 0.38 to 0.98; P = 0.04).

Conclusion

The combination of tamsulosin plus dutasteride provides a preferable therapeutic effect for BPH with a higher incidence of sexual side effects, but combination-therapy can markedly reduce risk of BPH-related symptom progression and acute urinary retention relative to tamsulosin monotherapy.

[Multiparametric MRI of the prostate : Important radiological findings for urologists]

CLINICAL/METHODICAL ISSUE

High prevalence of prostate cancer with multifocality and biological heterogeneity. Insufficient conventional urological diagnostics. Discrimination between significant and insignificant cancer needed.

STANDARD DIAGNOSTIC METHODS

Digital rectal examination, prostate-specific antigen (PSA) serum level, systematic transrectal ultrasound (TRUS)-guided prostate biopsy.

METHODICAL INNOVATIONS

Multiparametric magnetic resonance imaging (mpMRI) including T2-weighted (T2w), diffusion-weighted and dynamic contrast-enhanced MRI according to the prostate imaging reporting and data system (PIRADS), MR-targeted biopsy, most frequently MR/TRUS image fusion biopsy.

FINDINGS AND PERFORMANCE

Prostate cancer is characterized by low signal intensity on T2w MRI, restricted water diffusion and pronounced and early uptake of contrast enhancement. Sensitivity and specificity according to the current literature are ca. 80% and 90%, respectively.

PRACTICAL RECOMMENDATIONS

In cases of suspected prostate cancer, most accurate are mpMRI according to PIRADS and in cases of positive findings, MRI-targeted biopsy, most frequently as MRI/TRUS image fusion biopsy.

microRNA-372 Suppresses Migration and Invasion by Targeting p65 in Human Prostate Cancer Cells

Prostate cancer (PCa) is one of the most prevalent malignant tumors. microRNAs (miRNAs) play an important role in cancer initiation, progression, and metastasis, and their roles in PCa are becoming more apparent. In this study, we found that microRNA-372 (miR-372) is downregulated in human PCa and inhibits the proliferation activity, migration, and invasion of DU145 cells. Subsequently, p65 is confirmed as a target of miR-372, and knockdown of p65 expression similarly resulted in decreased proliferation activity, migration, and invasion. CDK8, MMP-9, and prostate-specific antigen were involved in both these processes. Taken together, our results show evidence that miR-372 may function as a tumor suppressor gene by regulating p65 in PCa and may provide a strategy for blocking PCa metastasis.

Identification of cell-free microRNAs in the urine of patients with prostate cancer

OBJECTIVES

Current methods for the early detection of prostate cancer (PCa), in particular prostate-specific antigen screening, are likely to benefit from complementary molecular analyses to enhance specificity. MicroRNAs (miRNA) are small endogenously expressed noncoding RNAs that negatively regulate the expression of protein-coding genes at the transcriptional or translational level. Accumulating evidence suggests that miRNAs play an important role in tumorigenesis, are differentially expressed in different cancer types, and can be found in all bodily fluids so-far tested, including urine.

METHODS AND MATERIALS

This study was undertaken to determine if miRNA could be isolated from the cell-free fraction of freely voided urine of PCa patients and if a miRNA signature could be found that would identify patients with cancer.

RESULTS

In a first set of proof-of-concept experiments, we isolated RNA from the supernatant of cultured PCa cells, as well as cellular RNA, and compared the expression of cell-free miRNAs vs. cellular miRNAs. We identified miRNA-483-5p, miRNA-1275, and miRNA-1290 among the most abundant cell-free miRNAs. We then tested the expression of these miRNAs in patient urine samples. A total of 18 patients without detectable PCa by transperineal template-saturation biopsy and 71 patients with diagnosed biopsy-proven PCa were retrospectively analyzed. We could confirm that cell-free miRNAs found in cultures of PCa cells can in fact be isolated from freely voided patients' urine. Furthermore, we found that patients with PCa express miR-483-5p in the cell-free urine fraction at a higher level than control patients do.

CONCLUSIONS

The present study is among the first to show that miRNAs can be detected in the cell-free, non-exosome-enriched fraction of urine collected from patients with PCa. As the method used here does not require isolation of exosomes, it could potentially simplify the future use of miRNAs as urine-based biomarkers.

miR-888 is an expressed prostatic secretions-derived microRNA that promotes prostate cell growth and migration

MicroRNAs (MiRNAs) are a growing class of small non-coding RNAs that exhibit widespread dysregulation in prostate cancer. We profiled miRNA expression in syngeneic human prostate cancer cell lines that differed in their metastatic potential in order to determine their role in aggressive prostate cancer. miR-888 was the most differentially expressed miRNA observed in human metastatic PC3-ML cells relative to non-invasive PC3-N cells, and its levels were higher in primary prostate tumors from cancer patients, particularly those with seminal vesicle invasion. We also examined a novel miRNA-based biomarker source called expressed prostatic secretions in urine (EPS urine) for miR-888 expression and found that its levels were preferentially elevated in prostate cancer patients with high-grade disease. These expression studies indicated a correlation for miR-888 in disease progression. We next tested how miR-888 regulated cancer-related pathways in vitro using human prostate cancer cell lines. Overexpression of miR-888 increased proliferation and migration, and conversely inhibition of miR-888 activity blocked these processes. miR-888 also increased colony formation in PC3-N and LNCaP cells, supporting an oncogenic role for this miRNA in the prostate. Our data indicates that miR-888 functions to promote prostate cancer progression and can suppress protein levels of the tumor suppressor genes RBL1 and SMAD4. This miRNA holds promise as a diagnostic tool using an innovative prostatic fluid source as well as a therapeutic target for aggressive prostate cancer.

The relationship between solar UV exposure, serum vitamin D levels and serum prostate-specific antigen levels, in men from New South Wales, Australia: the CHAMP study

PURPOSE

We aim to determine the relationship between season, personal solar UV exposure, serum 25(OH)D and 1,25(OH)2D and serum prostate-specific antigen (PSA) levels.

METHODS

Questionnaire data and blood samples were collected at baseline from participants of the Concord Health and Ageing in Men Project (n = 1,705), aged 70 and above. They were grouped as men 'free of prostate disease' for those with no record of having prostate cancer, benign prostatic hyperplasia, or prostatitis and with serum PSA levels below 20 ng/mL, and 'with prostate disease' for those with a record of either of these diseases or with serum PSA levels 20 ng/mL or above. Personal solar UV exposure (sUV) was estimated from recalled hours of outdoor exposure and weighted against ambient solar UV radiation. Sera were analysed to determine levels of PSA, 25(OH)D and 1,25(OH)2D, and analysed using multiple regression, adjusting for age, BMI and region of birth.

RESULTS

The association between sUV and serum PSA levels was conditional upon season (p interaction = 0.04). There was no direct association between serum PSA and 25(OH)D in both groups of men. There was a positive association between serum PSA and 1,25(OH)2D in men with prostate disease (mean = 110.6 pmol/L; p heterogeneity = 0.03), but there was no such association in men free of prostate disease (mean = 109.3 pmol/L; p heterogeneity = 0.8).

CONCLUSION

The association between PSA and sUV may only be evident at low solar UV irradiance, and this effect may be independent of serum vitamin D levels.

Screening for prostate cancer

BACKGROUND

Any form of screening aims to reduce disease-specific and overall mortality, and to improve a person's future quality of life. Screening for prostate cancer has generated considerable debate within the medical and broader community, as demonstrated by the varying recommendations made by medical organizations and governed by national policies. To better inform individual patient decision-making and health policy decisions, we need to consider the entire body of data from randomised controlled trials (RCTs) on prostate cancer screening summarised in a systematic review. In 2006, our Cochrane review identified insufficient evidence to either support or refute the use of routine mass, selective, or opportunistic screening for prostate cancer. An update of the review in 2010 included three additional trials. Meta-analysis of the five studies included in the 2010 review concluded that screening did not significantly reduce prostate cancer-specific mortality. In the past two years, several updates to studies included in the 2010 review have been published thereby providing the rationale for this update of the 2010 systematic review.

OBJECTIVES

To determine whether screening for prostate cancer reduces prostate cancer-specific mortality or all-cause mortality and to assess its impact on quality of life and adverse events.

SEARCH METHODS

An updated search of electronic databases (PROSTATE register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CANCERLIT, and the NHS EED) was performed, in addition to handsearching of specific journals and bibliographies, in an effort to identify both published and unpublished trials.

SELECTION CRITERIA

All RCTs of screening versus no screening for prostate cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The original search (2006) identified 99 potentially relevant articles that were selected for full-text review. From these citations, two RCTs were identified as meeting the inclusion criteria. The search for the 2010 version of the review identified a further 106 potentially relevant articles, from which three new RCTs were included in the review. A total of 31 articles were retrieved for full-text examination based on the updated search in 2012. Updated data on three studies were included in this review. Data from the trials were independently extracted by two authors.

MAIN RESULTS

Five RCTs with a total of 341,342 participants were included in this review. All involved prostate-specific antigen (PSA) testing, with or without digital rectal examination (DRE), though the interval and threshold for further evaluation varied across trials. The age of participants ranged from 45 to 80 years and duration of follow-up from 7 to 20 years. Our meta-analysis of the five included studies indicated no statistically significant difference in prostate cancer-specific mortality between men randomised to the screening and control groups (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.86 to 1.17). The methodological quality of three of the studies was assessed as posing a high risk of bias. The European Randomized Study of Screening for Prostate Cancer (ERSPC) and the US Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial were assessed as posing a low risk of bias, but provided contradicting results. The ERSPC study reported a significant reduction in prostate cancer-specific mortality (RR 0.84, 95% CI 0.73 to 0.95), whilst the PLCO study concluded no significant benefit (RR 1.15, 95% CI 0.86 to 1.54). The ERSPC was the only study of the five included in this review that reported a significant reduction in prostate cancer-specific mortality, in a pre-specified subgroup of men aged 55 to 69 years of age. Sensitivity analysis for overall risk of bias indicated no significant difference in prostate cancer-specific mortality when referring to the meta analysis of only the ERSPC and PLCO trial data (RR 0.96, 95% CI 0.70 to 1.30). Subgroup analyses indicated that prostate cancer-specific mortality was not affected by the age at which participants were screened. Meta-analysis of four studies investigating all-cause mortality did not determine any significant differences between men randomised to screening or control (RR 1.00, 95% CI 0.96 to 1.03). A diagnosis of prostate cancer was significantly greater in men randomised to screening compared to those randomised to control (RR 1.30, 95% CI 1.02 to 1.65). Localised prostate cancer was more commonly diagnosed in men randomised to screening (RR 1.79, 95% CI 1.19 to 2.70), whilst the proportion of men diagnosed with advanced prostate cancer was significantly lower in the screening group compared to the men serving as controls (RR 0.80, 95% CI 0.73 to 0.87). Screening resulted in a range of harms that can be considered minor to major in severity and duration. Common minor harms from screening include bleeding, bruising and short-term anxiety. Common major harms include overdiagnosis and overtreatment, including infection, blood loss requiring transfusion, pneumonia, erectile dysfunction, and incontinence. Harms of screening included false-positive results for the PSA test and overdiagnosis (up to 50% in the ERSPC study). Adverse events associated with transrectal ultrasound (TRUS)-guided biopsies included infection, bleeding and pain. No deaths were attributed to any biopsy procedure. None of the studies provided detailed assessment of the effect of screening on quality of life or provided a comprehensive assessment of resource utilization associated with screening (although preliminary analyses were reported).

AUTHORS' CONCLUSIONS

Prostate cancer screening did not significantly decrease prostate cancer-specific mortality in a combined meta-analysis of five RCTs. Only one study (ERSPC) reported a 21% significant reduction of prostate cancer-specific mortality in a pre-specified subgroup of men aged 55 to 69 years. Pooled data currently demonstrates no significant reduction in prostate cancer-specific and overall mortality. Harms associated with PSA-based screening and subsequent diagnostic evaluations are frequent, and moderate in severity. Overdiagnosis and overtreatment are common and are associated with treatment-related harms. Men should be informed of this and the demonstrated adverse effects when they are deciding whether or not to undertake screening for prostate cancer. Any reduction in prostate cancer-specific mortality may take up to 10 years to accrue; therefore, men who have a life expectancy less than 10 to 15 years should be informed that screening for prostate cancer is unlikely to be beneficial. No studies examined the independent role of screening by DRE.

PSA-based prostate cancer screening: the role of active surveillance and informed and shared decision making

Since the first publication describing the identification of prostate-specific antigen (PSA) in the 1960s, much progress has been made. The PSA test changed from being initially a monitoring tool to being also used as a diagnostic tool. Over time, the test has been heavily debated due to its lack of sensitivity and specificity. However, up to now the PSA test is still the only biomarker for the detection and monitoring of prostate cancer. PSA-based screening for prostate cancer is associated with a high proportion of unnecessary testing and overdiagnosis with subsequent overtreatment. In the early years of screening for prostate cancer, high rates of uptake were very important. However, over time the opinion on PSA-based screening has shifted towards the notion of informed choice. Nowadays, it is thought to be unethical to screen men without them being aware of the pros and cons of PSA testing, as well as the fact that an informed choice is related to better patient outcomes. Now, as the results of three major screening studies have been presented and the downsides of screening are becoming better understood, informed choice is becoming more relevant.

VEGF and prostatic cancer: a systematic review

Elevated vascular endothelial growth factor (VEGF) blood concentration reflects its prostatic production, making this a potentially interesting tumour marker to support the decision of submitting a patient for prostatic biopsy. The objective was to review systematically the evidence on the role of VEGF blood concentration in prostate cancer detection. Published studies addressing the relation between serum or plasma VEGF levels and prostate cancer were identified by searching Pubmed, ISI Web of Knowledge, SCOPUS and LILACS up to January 2010, and reviewed following a standardized protocol. Three studies reported higher plasma VEGF (pg/ml) in patients with localized prostate cancer than in healthy controls (7.0 vs. 0.0, 9.9 vs. 2.2, and 210 vs. 26.5, P<0.01), and two showed higher serum VEGF (pg/ml) in prostate cancer patients than in patients with benign prostate hypertrophy (518.9 vs. 267.9, P<0.001; no specific values, P<0.05). In one study, serum VEGF was significantly lower in healthy controls than in patients with benign prostate hypertrophy, localized or metastatic prostate cancer. The three studies that used controls with previous suspicion of prostatic cancer but a negative biopsy reported non-statistically significant difference in VEGF serum levels (pg/ml) between controls and localized prostate cancer patients (241 vs. 206; 69.5 vs. 55; 215.2 vs. 266.4). Higher VEGF plasma levels are observed in prostatic cancer patients compared with healthy controls, but serum levels do not appear to be useful in differentiating benign from malignant prostatic disease using, as controls, individuals with high risk of prostate cancer and negative biopsy.

Structural and functional analysis of human prostatic acid phosphatase

Prostatic acid phosphatase (PAP) is the most abundant phosphatase in human prostate tissue/secretions. It is a clinically important protein for its relevance as a biomarker of prostate carcinoma. Furthermore, it has a potential role in fertilization. We describe here most of the features of PAP including gene regulation, gene/protein structure, functions, its role in tumor progression and evolutionary features. PAP has phosphatase activity and is an extensively studied biomarker of prostate cancer. The major action of PAP is to dephosphorylate macromolecules with the help of catalytic residues (His(12) and Asp(258)) that are located in the cleft between two domains. This article will be of great interest to all those scientists who are working in the area of prostate pathophysiology.

Epigenetic mechanisms in cancer

After the completion of the human genome, a need was identified by scientists to look for a functional map of the human genome. Epigenomics provided functional characteristics of genes identified in the genome. Epigenetics is the alteration in gene expression (function) without changing the nucleotide sequence. Both activation and inactivation of cancer-associated genes can occur by epigenetic mechanisms. The major players in epigenetic mechanisms of gene regulation are DNA methylation, histone deacetylation, chromatin remodeling, small noncoding RNA expression and gene imprinting. In the last few years, epigenetic mechanisms have been studied in a number of tumor types and epigenetic markers have been identified that are suitable for cancer detection, diagnosis, follow-up of treatment and screening high-risk populations. One interesting aspect of epigenetics is the reactivation of genes by successful reversion of some epigenetic changes using chemicals. The reversibility of epigenetic aberrations has made them attractive targets for cancer treatment with modulators that demethylate DNA and inhibit histone deacetylases, leading to the reactivation of silenced genes. In this article, we have described the current status of this powerful science and discussed the challenges in the clinical fields where epigenetic approaches in cancer are applied.

Informed decision making on PSA testing for the detection of prostate cancer: an evaluation of a leaflet with risk indicator

BACKGROUND

Population-based screening for prostate cancer (PCa) remains controversial. To help men making informed decisions about prostate specific antigen (PSA) screening a risk indicator (www.uroweb.org) was developed. This risk indicator is embedded in a leaflet that informs men about the pros and cons of PCa screening and enables calculation of the individual risk of having a biopsy detectable PCa.

AIM

To assess the effect of providing a leaflet including individualized risk estimation on informed decision making of men, i.e. knowledge about PCa and PSA screening, attitude towards undergoing a PSA test and intention to have a PSA test.

METHODS

An intervention study among 2000 men, aged 55-65 years, randomly selected from the population registry of the city of Dordrecht, the Netherlands, in 2008. Men were sent a questionnaire on knowledge of PCa, attitude and intention to have a PSA test. Men without a history of (screening for) PCa were sent the leaflet and Questionnaire 2 within 2 weeks after returning Questionnaire 1. Validated health and anxiety measures were used.

RESULTS

One thousand and twenty seven of 2000 men completed Questionnaire 1 (51%), of whom 298 were excluded due to a history of (screening for) PCa. Of the 729 remaining men, 601 completed Questionnaire 2 as well. At the second assessment significantly more men met the requirements of informed decision making (15% versus 33%, p<0.001), more men had relevant knowledge (284/601, 50% versus 420/601, 77%, p<0.001) and the intention to have a PSA test had increased (p<0.001).

CONCLUSIONS

Providing information on PCa screening combined with individualized risk estimation enhanced informed decision making and may be used for shared decision making on PSA screening of physicians and patients.

Screening for prostate cancer

BACKGROUND

Any form of screening aims to reduce mortality and increase a person's quality of life. Screening for prostate cancer has generated considerable debate within the medical community, as demonstrated by the varying recommendations made by medical organizations and governed by national policies. Much of this debate is due to the limited availability of high quality research and the influence of false-positive or false-negative results generated by use of the diagnostic techniques such as the digital rectal examination (DRE) and prostate specific antigen (PSA) blood test.

OBJECTIVES

To determine whether screening for prostate cancer reduces prostate cancer mortality and has an impact on quality of life.

SEARCH STRATEGY

Electronic databases (PROSTATE register, CENTRAL the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CANCERLIT and the NHS EED) were searched electronically in addition to hand searching of specific journals and bibliographies in an effort to identify both published and unpublished trials.

SELECTION CRITERIA

All randomised controlled trials of screening versus no screening or routine care for prostate cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The search identified 99 potentially relevant articles that were selected for full text review. From these 99 citations, two randomised controlled trials were identified as meeting the review's inclusion criteria. Data from the trials were independently extracted by two authors.

MAIN RESULTS

Two randomised controlled trials with a total of 55,512 participants were included; however, both trials had methodological weaknesses. Re-analysis using intention-to-screen and meta-analysis of results from the two randomised controlled trials indicated no statistically significant difference in prostate cancer mortality between men randomised for prostate cancer screening and controls (RR 1.01, 95% CI: 0.80-1.29). Neither study assessed the effect of prostate cancer screening on quality of life, all-cause mortality or cost effectiveness.

AUTHORS' CONCLUSIONS

Given that only two randomised controlled trials were included, and the high risk of bias of both trials, there is insufficient evidence to either support or refute the routine use of mass, selective or opportunistic screening compared to no screening for reducing prostate cancer mortality. Currently, no robust evidence from randomised controlled trials is available regarding the impact of screening on quality of life, harms of screening, or its economic value. Results from two ongoing large scale multicentre randomised controlled trials that will be available in the next several years are required to make evidence-based decisions regarding prostate cancer screening.