COLONOMICS - integrative omics data of one hundred paired normal-tumoral samples from colon cancer patients

Colonomics is a multi-omics dataset that includes 250 samples: 50 samples from healthy colon mucosa donors and 100 paired samples from colon cancer patients (tumor/adjacent). From these samples, Colonomics project includes data from genotyping, DNA methylation, gene expression, whole exome sequencing and micro-RNAs (miRNAs) expression. It also includes data from copy number variation (CNV) from tumoral samples. In addition, clinical data from all these samples is available. The aims of the project were to explore and integrate these datasets to describe colon cancer at molecular level and to compare normal and tumoral tissues. Also, to improve screening by finding biomarkers for the diagnosis and prognosis of colon cancer. This project has its own website including four browsers allowing users to explore Colonomics datasets. Since generated data could be reuse for the scientific community for exploratory or validation purposes, here we describe omics datasets included in the Colonomics project as well as results from multi-omics layers integration.

Targeting metastasis-initiating cells through the fatty acid receptor CD36

The fact that the identity of the cells that initiate metastasis in most human cancers is unknown hampers the development of antimetastatic therapies. Here we describe a subpopulation of CD44^bright cells in human oral carcinomas that do not overexpress mesenchymal genes, are slow-cycling, express high levels of the fatty acid receptor CD36 and lipid metabolism genes, and are unique in their ability to initiate metastasis. Palmitic acid or a high-fat diet specifically boosts the metastatic potential of CD36⁺ metastasis-initiating cells in a CD36-dependent manner. The use of neutralizing antibodies to block CD36 causes almost complete inhibition of metastasis in immunodeficient or immunocompetent orthotopic mouse models of human oral cancer, with no side effects. Clinically, the presence of CD36⁺ metastasis-initiating cells correlates with a poor prognosis for numerous types of carcinomas, and inhibition of CD36 also impairs metastasis, at least in human melanoma- and breast cancer-derived tumours. Together, our results indicate that metastasis-initiating cells particularly rely on dietary lipids to promote metastasis.

Long-term prostate-specific antigen contamination in the Spanish arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC)

OBJECTIVES

Recently, the European Randomized Study of Screening for Prostate Cancer achieved a reduction in prostate cancer mortality by measuring serum prostate-specific antigen (PSA) levels. These results were not reproduced in the Spanish arm of European Randomized Study of Screening for Prostate Cancer. PSA contamination (opportunistic measurements outside the study) could decrease the study's contrasting power if performed in the control arm. We have calculated the long-term rate of PSA contamination and its effect on performing prostate biopsy and detecting cancer.

MATERIAL AND METHODS

A total of 4,276 men were randomised (2,415 to the screening arm, 1,861 to the control arm) in the Spanish section of the European Randomized Study of Screening for Prostate Cancer. PSA measurements were not scheduled in the control arm. Sextant prostate biopsy was indicated if PSA levels were ≥3 ng/mL. All PSA readings performed outside the study were labelled as "PSA contamination". We calculated the rates of PSA contamination, biopsy implementation and cancer detection.

RESULTS

The median age and follow-up time were 57 and 15.1 years, respectively. A total of 2,511 men underwent at least one PSA reading outside the study. PSA contamination at 5, 10 and 15 years was 22.0%, 47.1% and 66.3% in the screening arm, respectively, and 20.8%, 43.2% and 58.6% in the control arm, respectively (P<.0001). The biopsy rate at 5, 10 and 15 years was 19.3%, 22.6% and 24.1% (screening), respectively, and 1.0%, 3.6% and 7.1% (control), respectively (P<.0001). The PC detection rate was 6.7% (screening) and 4.3% (control; P=.0006).

CONCLUSIONS

Although the cumulative PSA contamination was pronounced in the 2 study arms, the rate of prostate biopsies was low in the control arm. We therefore believe that the effect of PSA contamination on the study's statistical power should be limited.

Update of the results of the Spanish branch of the European Randomized Study on Screening for Prostate Cancer (ERSPC)

OBJECTIVE

The role of prostate cancer (PC) screening is currently being questioned. The objective of the European Randomized Study of Screening for Prostate Cancer (ERSPC) was to demonstrate whether PC screening reduced mortality from this disease. The results from the Spanish branch of this study are presented: all-cause and cancer-specific mortality, the characteristics of the detected tumors, primary treatments and progression to advanced disease.

MATERIAL AND METHODS

A total of 18,612 men, between the ages of 45 and 70, were invited to participate in the study, excluding those with a life expectancy of less than 10 years. The men were randomized to the screening arm (serum prostate-specific antigen [PSA] reading) or the control arm (no diagnostic tests). Randomized transrectal ultrasound-guided sextant prostate biopsies were indicated for the men in the screening arm with PSA levels ≥3ng/ml. The detected PCs were identified (stage and primary treatment), as well as the deaths that occurred (date and cause of death).

RESULTS

The study was performed with 4276 men (2415 in the screening arm and 1861 in the control arm). The median age and serum PSA level were 57 years and 0.90ng/mL, respectively. The median follow-up time was 15.8 years. A total of 242 PCs were diagnosed, 162 (6.7%) in the screening arm and 80 (4.3%) in the control arm (P<.001). Of these, 214 (88.4%) had an organ-confined clinical stage at onset (91.4% in the screening arm vs. 82.5% in the control arm; P=.024). A total of 112 patients (46.3%) underwent radical prostatectomy, 53 (21.9%) underwent prostate radiation therapy, 24 (9.9%) underwent hormone therapy and 47 (19.4%) were kept under observation. A total of 18 PCs progressed to advanced disease (M+ or PSA levels >100ng/mL), with no differences between the study arms (P=.938). A total of 618 (14.5%) patients died during follow-up: 340 (14.1%) in the screening arm and 278 (14.9%) in the control arm, with no differences between the arms in terms of cancer-specific (P=.907) or all-cause (P=.399) mortality. The main causes of death were neoplasia (54.0%), cardiovascular (17.6%), respiratory (8.7%) and gastrointestinal (4.0%), with no difference between study arms. Of the 334 patients who died from neoplasia, only 12 (3.6%) died from PC.

CONCLUSIONS

PC screening results in a shifting of the diagnosis towards earlier stages. Nevertheless, we have not demonstrated a benefit in terms of overall or cancer-specific survival after more than 15 years of follow-up. The low mortality from this disease in our community could be one of the main factors that explain these results.

Assessing associations between the AURKA-HMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood approach. The association of HMMR rs299290 with breast cancer risk in BRCA1 mutation carriers was confirmed: per-allele hazard ratio (HR) = 1.10, 95% confidence interval (CI) 1.04-1.15, p = 1.9 x 10(-4) (false discovery rate (FDR)-adjusted p = 0.043). Variation in CSTF1, located next to AURKA, was also found to be associated with breast cancer risk in BRCA2 mutation carriers: rs2426618 per-allele HR = 1.10, 95% CI 1.03-1.16, p = 0.005 (FDR-adjusted p = 0.045). Assessment of pairwise interactions provided suggestions (FDR-adjusted pinteraction values > 0.05) for deviations from the multiplicative model for rs299290 and CSTF1 rs6064391, and rs299290 and TUBG1 rs11649877 in both BRCA1 and BRCA2 mutation carriers. Following these suggestions, the expression of HMMR and AURKA or TUBG1 in sporadic breast tumors was found to potentially interact, influencing patients' survival. Together, the results of this study support the hypothesis of a causative link between altered function of AURKA-HMMR-TPX2-TUBG1 and breast carcinogenesis in BRCA1/2 mutation carriers.

A monotonic and prognostic genomic signature from fibroblasts for colorectal cancer initiation, progression, and metastasis

The differential gene expression patterns between normal colonic fibroblasts (NCF), carcinoma-associated fibroblasts from primary tumors (CAF-PT), and CAFs from hepatic metastasis (CAF-LM) are hypothesized to be useful for predicting relapse in primary tumors. A transcriptomic profile of NCF (n = 9), CAF-PT (n = 14), and CAF-LM (n = 11) was derived. Prediction Analysis of Microarrays (PAM) was used to obtain molecular details for each fibroblast class, and differentially expressed transcripts were used to classify patients according to recurrence status. A number of transcripts (n = 277) were common to all three types of fibroblasts and whose expression level was sequentially deregulated according to the transition: NCF→CAF-PT→CAF-LM. Importantly, the gene signature was able to accurately classify patients with primary tumors according to their prognosis. This capacity was exploited to obtain a refined 19-gene classifier that predicted recurrence with high accuracy in two independent datasets of patients with colorectal cancer and correlates with fibroblast migratory potential. The prognostic power of this genomic signature is strong evidence of the link between the tumor-stroma microenvironment and cancer progression. Furthermore, the 19-gene classifier was able to identify low-risk patients very accurately, which is of particular importance for stage II patients, who would benefit from the omission of chemotherapy, especially T4N0 patients, who are clinically classified as being at high risk.

IMPLICATIONS

A defined stromal gene expression signature predicts relapse in patients with colorectal cancer.

Differences between CAFs and their paired NCF from adjacent colonic mucosa reveal functional heterogeneity of CAFs, providing prognostic information

Little is known about the difference in gene expression between carcinoma-associated fibroblasts (CAFs) and paired normal colonic fibroblasts (NCFs) in colorectal cancer. Paired CAFs and NCFs were isolated from eight primary human colorectal carcinoma specimens. In culture conditions, soluble factors secreted by CAFs in the conditioned media increased clonogenicity and migration of epithelial cancer cells lines to a greater extent than did NCF. In vivo, CAFs were more competent as tumour growth enhancers than paired NCFs when co-inoculated with colorectal cell lines. Gene expression analysis of microarrays of CAF and paired NCF populations enabled us to identify 108 deregulated genes (38 upregulated and 70 downregulated genes). Most of those genes are fibroblast-specific. This has been validated in silico in dataset GSE39396 and by qPCR in selected genes. GSEA analysis revealed a differential transcriptomic profile of CAFs, mainly involving the Wnt signallingsignalling pathway, focal adhesion and cell cycle. Both deregulated genes and biological processes involved depicted a considerable degree of overlap with deregulated genes reported in breast, lung, oesophagus and prostate CAFs. These observations suggest that similar transcriptomic programs may be active in the transition from normal fibroblast in adjacent tissues to CAFs, independently of their anatomic demarcation. Additionally NCF already depicted an activated pattern associated with inflammation. The deregulated genes signature score seemed to correlate with CAF tumour promoter abilities in vitro, suggesting a high degree of heterogeneity between CAFs, and it has also prognostic value in two independent datasets. Further characterization of the roles these biomarkers play in cancer will reveal how CAFs provide cancer cells with a suitable microenvironment and may help in the development of new therapeutic targets for cancer treatment.

Identification of candidate susceptibility genes for colorectal cancer through eQTL analysis

In this study, we aim to identify the genes responsible for colorectal cancer risk behind the loci identified in genome-wide association studies (GWAS). These genes may be candidate targets for developing new strategies for prevention or therapy. We analyzed the association of genotypes for 26 GWAS single nucleotide polymorphisms (SNPs) with the expression of genes within a 2 Mb region (cis-eQTLs). Affymetrix Human Genome U219 expression arrays were used to assess gene expression in two series of samples, one of healthy colonic mucosa (n = 47) and other of normal mucosa adjacent to colon cancer (n = 97, total 144). Paired tumor tissues (n = 97) were also analyzed but did not provide additional findings. Partial Pearson correlation (r), adjusted for sample type, was used for the analysis. We have found Bonferroni-significant cis-eQTLs in three loci: rs3802842 in 11q23.1 associated to C11orf53, COLCA1 (C11orf92) and COLCA2 (C11orf93; r = 0.60); rs7136702 in 12q13.12 associated to DIP2B (r = 0.63) and rs5934683 in Xp22.3 associated to SHROOM2 and GPR143 (r = 0.47). For loci in chromosomes 11 and 12, we have found other SNPs in linkage disequilibrium that are more strongly associated with the expression of the identified genes and are better functional candidates: rs7130173 for 11q23.1 (r = 0.66) and rs61927768 for 12q13.12 (r = 0.86). These SNPs are located in DNA regions that may harbor enhancers or transcription factor binding sites. The analysis of trans-eQTLs has identified additional genes in these loci that may have common regulatory mechanisms as shown by the analysis of protein-protein interaction networks.

Prostate cancer incidence and mortality in the Spanish section of the European Randomized Study of Screening for Prostate Cancer (ERSPC)

BACKGROUND

To present the long-term results of a prostate cancer (PC) screening trial conducted in a Mediterranean setting.

METHODS

A total of 4276 men aged 45-70 years were randomized to screening arm (PSA test performed) and control arm (no tests). Transrectal ultrasonography-guided sextant prostate biopsy was conducted when PSA > or = 3 ng ml(-1). Date and cause of death were retrieved from death certificates. PC incidence, and disease-specific and overall mortality curves were plotted and comparison between arms was made. Analysis of causes of death was also performed.

RESULTS

Median age at randomization was 57.0 years. Median follow-up time was 15.2 years. A total of 241 men were diagnosed with PC, 161 (6.7%) in the screening arm and 80 (4.3%) in the control arm (P<0.01). Eventually, 554 men (13%) died. No difference in all-cause mortality was found between arms (P=0.34). Only 10 men (10/4276, 0.23%) died from PC, no differences between arms (P=0.67). Overall, the main causes of death were malignancy (54.2%), cardiovascular (17.9%) and respiratory (9.2%) diseases. Main cancer causes of death were lung and bronchus cancer (37.2%), colorectum (15.0%) and stomach (9.0%) cancer. PC only accounted for 3.0% of all malignant causes of death (ranked 10th).

CONCLUSIONS

Our study failed to demonstrate benefits of PC screening in terms of all-cause and PC-specific mortality after a median follow-up of 15 years. The limited sample size and the low long-term PC mortality observed in our setting were probably the most important factors to explain these results.

Aberrant gene expression in mucosa adjacent to tumor reveals a molecular crosstalk in colon cancer

Background

A colorectal tumor is not an isolated entity growing in a restricted location of the body. The patient’s gut environment constitutes the framework where the tumor evolves and this relationship promotes and includes a complex and tight correlation of the tumor with inflammation, blood vessels formation, nutrition, and gut microbiome composition. The tumor influence in the environment could both promote an anti-tumor or a pro-tumor response.

Methods

A set of 98 paired adjacent mucosa and tumor tissues from colorectal cancer (CRC) patients and 50 colon mucosa from healthy donors (246 samples in total) were included in this work. RNA extracted from each sample was hybridized in Affymetrix chips Human Genome U219. Functional relationships between genes were inferred by means of systems biology using both transcriptional regulation networks (ARACNe algorithm) and protein-protein interaction networks (BIANA software).

Results

Here we report a transcriptomic analysis revealing a number of genes activated in adjacent mucosa from CRC patients, not activated in mucosa from healthy donors. A functional analysis of these genes suggested that this active reaction of the adjacent mucosa was related to the presence of the tumor. Transcriptional and protein-interaction networks were used to further elucidate this response of normal gut in front of the tumor, revealing a crosstalk between proteins secreted by the tumor and receptors activated in the adjacent colon tissue; and vice versa. Remarkably, Slit family of proteins activated ROBO receptors in tumor whereas tumor-secreted proteins transduced a cellular signal finally activating AP-1 in adjacent tissue.

Conclusions

The systems-level approach provides new insights into the micro-ecology of colorectal tumorogenesis. Disrupting this intricate molecular network of cell-cell communication and pro-inflammatory microenvironment could be a therapeutic target in CRC patients.

Integrating gene expression and epidemiological data for the discovery of genetic interactions associated with cancer risk

Dozens of common genetic variants associated with cancer risk have been identified through genome-wide association studies (GWASs). However, these variants only explain a modest fraction of the heritability of disease. The missing heritability has been attributed to several factors, among them the existence of genetic interactions (G × G). Systematic screens for G × G in model organisms have revealed their fundamental influence in complex phenotypes. In this scenario, G × G overlap significantly with other types of gene and/or protein relationships. Here, by integrating predicted G × G from GWAS data and complex- and context-defined gene coexpression profiles, we provide evidence for G × G associated with cancer risk. G × G predicted from a breast cancer GWAS dataset identified significant overlaps [relative enrichments (REs) of 8-36%, empirical P values < 0.05 to 10(-4)] with complex (non-linear) gene coexpression in breast tumors. The use of gene or protein data not specific for breast cancer did not reveal overlaps. According to the predicted G × G, experimental assays demonstrated functional interplay between lipoma-preferred partner and transforming growth factor-β signaling in the MCF10A non-tumorigenic mammary epithelial cell model. Next, integration of pancreatic tumor gene expression profiles with pancreatic cancer G × G predicted from a GWAS corroborated the observations made for breast cancer risk (REs of 25-59%). The method presented here can potentially support the identification of genetic interactions associated with cancer risk, providing novel mechanistic hypotheses for carcinogenesis.

Clinical value of prognosis gene expression signatures in colorectal cancer: a systematic review

Introduction

The traditional staging system is inadequate to identify those patients with stage II colorectal cancer (CRC) at high risk of recurrence or with stage III CRC at low risk. A number of gene expression signatures to predict CRC prognosis have been proposed, but none is routinely used in the clinic. The aim of this work was to assess the prediction ability and potential clinical usefulness of these signatures in a series of independent datasets.

Methods

A literature review identified 31 gene expression signatures that used gene expression data to predict prognosis in CRC tissue. The search was based on the PubMed database and was restricted to papers published from January 2004 to December 2011. Eleven CRC gene expression datasets with outcome information were identified and downloaded from public repositories. Random Forest classifier was used to build predictors from the gene lists. Matthews correlation coefficient was chosen as a measure of classification accuracy and its associated p-value was used to assess association with prognosis. For clinical usefulness evaluation, positive and negative post-tests probabilities were computed in stage II and III samples.

Results

Five gene signatures showed significant association with prognosis and provided reasonable prediction accuracy in their own training datasets. Nevertheless, all signatures showed low reproducibility in independent data. Stratified analyses by stage or microsatellite instability status showed significant association but limited discrimination ability, especially in stage II tumors. From a clinical perspective, the most predictive signatures showed a minor but significant improvement over the classical staging system.

Conclusions

The published signatures show low prediction accuracy but moderate clinical usefulness. Although gene expression data may inform prognosis, better strategies for signature validation are needed to encourage their widespread use in the clinic.

Cancer develops, progresses and responds to therapies through restricted perturbation of the protein-protein interaction network

Robustness of cancer-related gene expression changes in the interactome network.

The products of genes mutated or differentially expressed in cancer tend to occupy central positions within the network of protein–protein interactions, or the interactome network. Integration of different types of gene and protein relationships has considerably increased the understanding of the mechanisms of carcinogenesis, while also enhancing the applicability of expression signatures. In this scenario, however, it remains unknown how cancer develops, progresses and responds to therapies in a potentially controlled manner at the systems level. Here, by applying the concepts of load transfer and cascading failures in power grids, we examine the impact and transmission of cancer-related gene expression changes in the interactome network. Relative to random perturbations, this study reveals topological robustness associated with all cancer conditions. In addition, experimental perturbation of a central cancer node, which consists of over-expression of the α-synuclein (SNCA) protein in MCF7 breast cancer cells, also reveals robustness. Conversely, a search for proteins with an opposite topological impact identifies the autophagy pathway. Mechanistically, the existence of smaller shortest paths among cancer-related proteins appears to be a topological feature that partially contributes to the restricted perturbation of the network. Together, the results of this study suggest that cancer develops, progresses and responds to therapies following controlled, restricted perturbation of the interactome network.

[Mortality due to prostate cancer in the Spanish arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC). Results after a 15-year follow-up]

OBJECTIVE

To address if prostate cancer (PCa) screening decreases PCa mortality in the asymptomatic population, within the setting of the Spanish arm of the European Randomized Study of Screening for Prostate Cancer (ERSPC).

MATERIAL AND METHODS

From 1996 to 1999, 4,278 men aged 45-70 years were recruited and randomized to the screening arm (PSA every 4 years, prostate biopsy when PSA ≥3 ng/ml) and control arm (no tests). Dates and causes of death were collected on an annual basis. A Kaplan-Meier analysis was used to calculate overall and cancer-specific survival.

RESULTS

A total of 2,416 men were recruited in the screening arm and 1,862 in the control arm. Mean age was 57.8 years, median follow-up was 13.3 years. At the end of the follow-up period, 427 deaths (9 from PCa) were observed. Survival analysis did not show any difference between the study arms with respect to overall and cancer-specific survival (p=0.939 and p=0.544 respectively). Most relevant causes of death were malignant tumors (52.9%), cardiovascular disease (17.3%) and respiratory (8.9%). Only 2.1% of deaths (0.2% of all recruited men) were due to PCa (2.5% screening, 1.6% control).

CONCLUSIONS

The Spanish arm of ERSPC failed to reproduce the long-term results shown in the whole study. No differences in mortality (overall or cancer-specific) were observed after 15 years of follow-up. PCa mortality was infrequent (less than 1%). These results suggest limited yield of PCa screening in our setting.

Exploring the link between germline and somatic genetic alterations in breast carcinogenesis

Recent genome-wide association studies (GWASs) have identified candidate genes contributing to cancer risk through low-penetrance mutations. Many of these genes were unexpected and, intriguingly, included well-known players in carcinogenesis at the somatic level. To assess the hypothesis of a germline-somatic link in carcinogenesis, we evaluated the distribution of somatic gene labels within the ordered results of a breast cancer risk GWAS. This analysis suggested frequent influence on risk of genetic variation in loci encoding for "driver kinases" (i.e., kinases encoded by genes that showed higher somatic mutation rates than expected by chance and, therefore, whose deregulation may contribute to cancer development and/or progression). Assessment of these predictions using a population-based case-control study in Poland replicated the association for rs3732568 in EPHB1 (odds ratio (OR) = 0.79; 95% confidence interval (CI): 0.63-0.98; P(trend) = 0.031). Analyses by early age at diagnosis and by estrogen receptor α (ERα) tumor status indicated potential associations for rs6852678 in CDKL2 (OR = 0.32, 95% CI: 0.10-1.00; P(recessive) = 0.044) and rs10878640 in DYRK2 (OR = 2.39, 95% CI: 1.32-4.30; P(dominant) = 0.003), and for rs12765929, rs9836340, rs4707795 in BMPR1A, EPHA3 and EPHA7, respectively (ERα tumor status P(interaction)<0.05). The identification of three novel candidates as EPH receptor genes might indicate a link between perturbed compartmentalization of early neoplastic lesions and breast cancer risk and progression. Together, these data may lay the foundations for replication in additional populations and could potentially increase our knowledge of the underlying molecular mechanisms of breast carcinogenesis.

Adherence to the Mediterranean diet and risk of coronary heart disease in the Spanish EPIC Cohort Study

No known cohort study has investigated whether the Mediterranean diet can reduce incident coronary heart disease (CHD) events in a Mediterranean population. This study examined the relation between Mediterranean diet adherence and risk of incident CHD events in the 5 Spanish centers of the European Prospective Investigation into Cancer and Nutrition. Analysis included 41,078 participants aged 29-69 years, recruited in 1992-1996 and followed up until December 2004 (mean follow-up:10.4 years). Confirmed incident fatal and nonfatal CHD events were analyzed according to Mediterranean diet adherence, measured by using an 18-unit relative Mediterranean diet score. A total of 609 participants (79% male) had a fatal or nonfatal confirmed acute myocardial infarction (n = 468) or unstable angina requiring revascularization (n = 141). After stratification by center and age and adjustment for recognized CHD risk factors, high compared with low relative Mediterranean diet score was associated with a significant reduction in CHD risk (hazard ratio = 0.60, 95% confidence interval: 0.47, 0.77). A 1-unit increase in relative Mediterranean diet score was associated with a 6% reduced risk of CHD (95% confidence interval: 0.91, 0.97), with similar risk reductions by sex. Mediterranean diet adherence was associated with a significantly reduced CHD risk in this Mediterranean country, supporting its role in primary prevention of CHD in healthy populations.

Biological convergence of cancer signatures

Gene expression profiling has identified cancer prognostic and predictive signatures with superior performance to conventional histopathological or clinical parameters. Consequently, signatures are being incorporated into clinical practice and will soon influence everyday decisions in oncology. However, the slight overlap in the gene identity between signatures for the same cancer type or condition raises questions about their biological and clinical implications. To clarify these issues, better understanding of the molecular properties and possible interactions underlying apparently dissimilar signatures is needed. Here, we evaluated whether the signatures of 24 independent studies are related at the genome, transcriptome or proteome levels. Significant associations were consistently observed across these molecular layers, which suggest the existence of a common cancer cell phenotype. Convergence on cell proliferation and death supports the pivotal involvement of these processes in prognosis, metastasis and treatment response. In addition, functional and molecular associations were identified with the immune response in different cancer types and conditions that complement the contribution of cell proliferation and death. Examination of additional, independent, cancer datasets corroborated our observations. This study proposes a comprehensive strategy for interpreting cancer signatures that reveals common design principles and systems-level properties.

Predictors of early and late ventricular remodeling after acute myocardial infarction

BACKGROUND

The determinants of the early and late stages of the ventricular remodeling process after infarction are not well defined.

HYPOTHESIS

The study was undertaken to evaluate the factors that condition the time course of left ventricular dilation during the first 6 months after infarction.

METHODS

The study group consisted of 74 patients with a first intermediate-large (> or = 4 Q waves) acute myocardial infarction. Contrast left ventricular and coronary angiograms were performed at 7 +/- 1 and 175 +/- 25 days after infarction. Left ventricular volumes, regional function and infarction artery status were quantified. Percutaneous transluminal coronary angioplasty (PTCA) was performed in the early angiogram in 31 patients.

RESULTS

In the early angiogram, 13 patients showed ventricular remodeling (end-diastolic volume > 90 ml/m2). A larger extent of dysfunction was the only predictor (p < 0.002) of early remodeling. At 6 months, a smaller, early end-diastolic volume (p < 0.0001) and a poorer regional function recovery (p < 0.05) were independently related to late diastolic enlargement, and a poorer regional function recovery (p < 0.0001) and a smaller, early end-systolic volume (p < 0.009) were independently related to late systolic enlargement. One patient with compared with 20 patients without early remodeling (p < 0.04) presented with late remodeling (increment of the end-diastolic volume > 20% at 6 months). In patients with early remodeling, the end-diastolic volume did not change significantly (101 +/- 13 vs. 94 +/- 22 ml/m2, NS) at 6 months; despite this, they maintained larger diastolic volumes than patients with late remodeling (81 +/- 12 ml/m2, p < 0.04) at 6 months. Infarction artery status did not influence the evolution of ventricular volumes and regional function.

CONCLUSIONS

(1) A large infarct size is the main determinant of postinfarction remodeling. (2) Such infarct size-dependent ventricular dilation occurs early and does not tend to increase in late stage; in contrast, some cases of intermediate-large size infarcts without early remodeling exhibit late remodeling associated with a poor late recovery of regional function. (3) Recovery of regional function (indicating myocardial viability) rather than infarction artery status plays a role in the late ventricular remodeling process.

Biological processes, properties and molecular wiring diagrams of candidate low-penetrance breast cancer susceptibility genes

Background

Recent advances in whole-genome association studies (WGASs) for human cancer risk are beginning to provide the part lists of low-penetrance susceptibility genes. However, statistical analysis in these studies is complicated by the vast number of genetic variants examined and the weak effects observed, as a result of which constraints must be incorporated into the study design and analytical approach. In this scenario, biological attributes beyond the adjusted statistics generally receive little attention and, more importantly, the fundamental biological characteristics of low-penetrance susceptibility genes have yet to be determined.

Methods

We applied an integrative approach for identifying candidate low-penetrance breast cancer susceptibility genes, their characteristics and molecular networks through the analysis of diverse sources of biological evidence.

Results

First, examination of the distribution of Gene Ontology terms in ordered WGAS results identified asymmetrical distribution of Cell Communication and Cell Death processes linked to risk. Second, analysis of 11 different types of molecular or functional relationships in genomic and proteomic data sets defined the "omic" properties of candidate genes: i/ differential expression in tumors relative to normal tissue; ii/ somatic genomic copy number changes correlating with gene expression levels; iii/ differentially expressed across age at diagnosis; and iv/ expression changes after BRCA1 perturbation. Finally, network modeling of the effects of variants on germline gene expression showed higher connectivity than expected by chance between novel candidates and with known susceptibility genes, which supports functional relationships and provides mechanistic hypotheses of risk.

Conclusion

This study proposes that cell communication and cell death are major biological processes perturbed in risk of breast cancer conferred by low-penetrance variants, and defines the common omic properties, molecular interactions and possible functional effects of candidate genes and proteins.

Consumption of cruciferous vegetables and glucosinolates in a Spanish adult population

OBJECTIVE

To assess the intake of glucosinolates and cruciferous vegetables among Spanish adults.

DESIGN

Cross-sectional analysis of a prospective cohort study.

SETTING

The Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).

SUBJECTS

We analysed data from 40 684 men and women aged 35-64 years from the EPIC-Spain cohort. The usual diet was assessed by means of the dietary history method, and glucosinolate intake was calculated using a published food composition database.

RESULTS

The average intake of cruciferous vegetables was 11.3 g/day, accounting for about 5% of total vegetable consumption, whereas the daily intake of total glucosinolates was 6.5 mg, among which 35% were of indole type. The absolute intake of glucosinolates was in average higher in men than in women (6.8 vs 6.2 mg/day), whereas glucosinolate density per energy unit was higher in women's diet (3.4 vs 2.7 mg/4200 kJ). Northern regions consumed in average 36% more glucosinolates than Southern regions (7.3 vs 5.4 mg/day). There was a positive association of glucosinolate intake with body mass index, physical activity, educational level and an inverse relationship with alcohol consumption.

CONCLUSIONS

Contrary to the pattern seen for total vegetable intake, our estimate of consumption of cruciferous vegetables, and hence of glucosinolates, is relatively low within Europe, which in turn is lower than in North America and several Asian populations.

Validity of self reported diagnoses of cancer in a major Spanish prospective cohort study

INTRODUCTION

This study aims to assess the validity of self reported diagnoses of cancer by persons recruited for the Spanish EPIC (European prospective investigation into cancer and nutrition) cohort study and to identify variables associated with correctly reporting a diagnosis of cancer.

METHODS

41 440 members of EPIC were asked at the time of recruitment whether they had been diagnosed with cancer and the year of diagnosis and site. The process of validating self reported diagnoses of cancer included comparison of the cohort database with the data from the population based cancer registries. Cancer diagnostic validity tests were calculated. The association between a correct report and certain sociodemographic, tumour related, or health related variables were analysed by logistic regression.

RESULTS

The overall sensitivity of self reported diagnoses of cancer is low (57.5%; 95% CI: 51.9 to 63.0), the highest values being shown by persons with a higher level of education or with a family history of cancer and the lowest values by smokers. Breast and thyroid cancers are those with the highest diagnostic validity and uterus, bladder, and colon-rectum those with the lowest. In both sexes the variables showing a significant association with a correct report of cancer are: higher education level, number of previous pathologies, invasive tumour, and, in women, a history of gynaecological surgery.

CONCLUSIONS

The overall sensitivity of self reported diagnoses of cancer is comparatively low and it is not recommended in epidemiological studies for identifying tumours. However, self reported diagnoses might be highly valid for certain tumour sites, malignant behaviour, and average to high levels of education.

Changes in food supply in Mediterranean countries from 1961 to 2001

OBJECTIVE

To describe geographical differences and time trends in the supply of the most important food components of the traditional Mediterranean diet.

DESIGN

Food supply data collected from national food balance sheets for the period 1961-2001.

SETTING

Selected Mediterranean countries: Spain, Italy, France, Greece, Algeria, Morocco, Tunisia and Turkey.

RESULTS

Differences of almost 30-fold and five-fold were found in the supply of olive oil and fruits and vegetables, respectively, among the Mediterranean countries studied during the 1960s. A favourable increasing trend for the supply of fruit and vegetables was observed in most Mediterranean countries. However, an increase in the supply of meats and dairy products and a decrease in the supply of cereals and wine were observed in European Mediterranean countries from 1961 until 2001. Only in African and Asiatic Mediterranean countries were cereals the base of food supply. During the 1990s, Greece's food supply pattern was closest to the traditional Mediterranean diet, while Italy and Spain maintained a high availability of fruits, vegetables and olive oil, but were losing the other typical components. Among African and Asiatic Mediterranean countries, only Turkey presented a traditional Mediterranean dietary pattern except with respect to olive oil, the supply of which was very low. France showed a Western dietary pattern, with a high supply of animal products and a low supply of olive oil.

CONCLUSIONS

Dietary supplies in the Mediterranean area were quite heterogeneous in the 1960s and have experienced a process of Westernization, especially in European Mediterranean countries.

Reliability of bulky DNA adducts measurement by the nuclease P1 32P-post-labelling technique

The aim was to assess the reliability of bulky DNA adducts measurement by means of the 32P-post-labelling assay. The research design consisted of an intramethod reliability study. Buffy coats from 41 subjects were used to obtain two aliquots of 1-5 microg DNA for each subject; bulky DNA adducts were measured using the nuclease P1 32P-post-labelling technique. The reliability of the measurement was assessed by means of the intraclass correlation coefficient (ICC), the distribution of the differences between the two measurements and the limits of agreement. The estimated ICC was 0.977, with a 95% confidence interval between 0.921 and 0.977. The limits of agreement were +/- 0.44 (DNA adducts per 10(8) nucleotides). Only three subjects had differences lying out of such limits. Bulky DNA adduct levels measured by the 32P-post-labelling technique showed good reliability. Only one measurement is needed to use DNA adducts as a biomarker of exposure and, possibly, cancer risk. Besides, as a validation analysis, 32P-post-labelling measurements can be repeated in only 20-30% of samples.

Quantitative real-time reverse transcription: polymerase chain reaction of prostate-specific antigen (PSA) for detection of circulating prostatic cells in patients with clinically localized prostate cancer

OBJECTIVE

To evaluate the clinical utility of using the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify prostate-specific antigen (PSA) mRNA in peripheral blood samples from patients with prostate cancer as a predictor of extraprostatic extension of the disease and to assess any correlations with known predictive markers of this condition.

METHODS

Immediately before radical prostatectomy, peripheral blood samples were taken from 42 men with clinically localized prostate cancer and analysed for PSA and 18S ribosomal (endogenous control) genes using real-time RT-PCR (with gene expression assays and the comparative CT-cycle threshold-method for quantifying). A total of 30 healthy male blood donors aged <50 y was taken as a control group. The relationships between PSA mRNA values, pathological and clinical features were analysed. PSA mRNA value, PSA level and biopsy Gleason score were then compared as predictors of extraprostatic extension.

RESULTS

PSA gene expression was 3.73 times significantly higher in patients with clinically localized prostate cancer than in healthy men (P<0.05). There was no relationship between PSA real-time RT-PCR values and pathological stage pT2 or pT3 (P=0.5), and no association between PSA mRNA value and serum PSA level (P=0.9) or the Gleason score of the preoperative biopsy (P=0.9).

CONCLUSION

There was no significant advantage in using the real-time RT-PCR assay of PSA mRNA before surgery to stage prostate cancer and to discriminate between organ-confined and extraprostatic extension.

Prostate cancer detection and tumor characteristics in men with multiple biopsy sessions

PURPOSES

To address prostate cancer (PCa) detection with respect to the number of biopsy sessions performed, to identify risk factors for detection after a negative biopsy, and to analyze the clinical characteristics of the detected tumors.

SCOPE

Only biopsied men (sextant) were included. A total of 1011 biopsy sessions were carried out in 770 men; 172 underwent a second prostate biopsy and 51 a third biopsy. During the first biopsy round, 111 cancers were found (14.4%), 27 in the second (15.7%), and five during the third round (9.8%), P=0.156. Only high-grade PIN or atypia were identified as independent predictors or PCa detection in subsequent biopsies (P=0.008). A nonsignificant increase of clinically localized tumors, and a decrease of metastatic and poorly differentiated cases were found when more biopsy sessions were needed for detection.

CONCLUSIONS

A nonsignificant trend to lower cancer detection rates and less clinical relevance of the tumors detected can be observed when more biopsy rounds are needed for detection.

Prostate apoptosis after doxazosin treatment in the spontaneous hypertensive rat model

OBJECTIVE

To validate the spontaneous hypertensive rat (SHR) model for basic research into benign prostate hyperplasia (BPH), and to assess doxazosin-induced changes in prostatic structure and apoptotic status.

MATERIALS AND METHODS

Four groups of rats were assessed: group 1, 15 SHRs treated with doxazosin; group 2, 14 SHRs with unilateral excision of the major pelvic ganglion; group 3, 14 untreated SHRs; and group 4, 16 intact Wistar-Kyoto (WKY) rats. The doxazosin mesylate (0.03 mg daily) was given compacted in rat food for 3 months. The prostatic ventral lobe (VL) was excised and weighed. Stereological light microscopy, multiplex reverse transcription-polymerase chain reaction of prostate caspases, and caspase-3 activity (cellular enzymatic assay) were assessed.

RESULTS

There was more development of the glandular epithelium (P < 0.001) in SHR rats than in controls, which was even greater after doxazosin exposure (P = 0.027). SHR animals had higher caspase expression (P < 0.05) and activity (P = 0.008) than WKY rats, but both were reduced after doxazosin therapy (P < 0.01 and 0.028, respectively).

CONCLUSIONS

This study confirmed prostate hyperplasia in the SHR model. Doxazosin exposure did not reduce the volume of glandular epithelium and contributed to protecting against caspase-induced apoptosis. The SHR model may be not a valid option to study doxazosin-induced apoptosis in BPH.

Four-year prostate-specific antigen progression in the non-cancer population of the European Randomized Study of Screening for Prostate Cancer

OBJECTIVE

To determine the rate of conversion of prostate-specific antigen (PSA) to values of > 4 ng/mL in a normal male population.

PATIENTS AND METHODS

In men with an initial PSA level of < 4 ng/mL the probability of having a PSA of > or = 4 ng/mL and its relationship with the age at first PSA test, baseline PSA level and time to the determination was evaluated. Statistical methods were used to correct for the within-subject variability across many PSA determinations.

RESULTS

In all, 45433 PSA tests in 21169 men with an initial PSA of < 4 ng/mL were available. Overall, in 960 men (4.5%) the PSA level changed to > or = 4 ng/mL. The lowest chance was for men aged < 55 years with an initial PSA of < 1 ng/mL and a new PSA determination during the first 18 months (0.952 conversions per 1000 men) while the highest was for men aged < 55 years with an initial PSA level of > 2.5 ng/mL (395 conversions per 1000 men). There was a significant and independent relationship between conversion and the interval between determinations, with conversion being 3.33 times more frequent during 18-42 months than with the reference category (< 18 months) and 5.23 times more frequent during > 42 months. The probability of conversion independently increased by 3 lambda for every additional year of age. Every unit of basal PSA multiplied by 6.48 the probability of conversion.

CONCLUSIONS

The risk for conversion to a PSA of > or = 4 ng/mL can be anticipated from the patient's age and initial PSA level. Re-screening before 4 years after the first round can be useless for men with an initial PSA of < 1 ng/mL. Four-year intervals could be inadequate for men with an initial PSA of > 2.5 ng/mL if conversion to > 4 ng/mL is to be avoided.

The Spanish contribution to the European Randomized Study of Screening for Prostate Cancer

OBJECTIVE

To summarize the experience of the Spanish participation in the European Randomized Study of Screening for Prostate Cancer (ERSPC).

METHODS

In this study men aged 45-70 years were randomized (1:1) and allocated to one of two arms: screening, with an indication for transrectal ultrasonography (TRUS) and sextant prostate biopsy when the serum prostate-specific antigen (PSA) level was >4 ng/mL (until May 1998) and from then when the PSA was >2.9 ng/mL; and a control group (no diagnostic tests). The findings from a digital rectal examination were not considered as a criterion for biopsy. When the serum PSA was above the threshold levels, biopsy-negative men were invited again after a year ('early recall'). The next (second) screening round was programmed for the rest of participants after a 4-year interval. Cancer-specific mortality was recorded and compared in both groups.

RESULTS

In all, 4278 men were recruited (2416 in the screening group and 1862 in the control group). The recruitment phase was closed in June 1999. During the first screening round 40 cancers were detected; the detection rate was then 1.7% and 4.15 biopsies were needed to detect each cancer. The clinical stage was localized in 88.6% and regional or metastatic in 11.4%. Within the first round, 17 more cancers were detected at early recall attendance. During the second screening round 14 cancers were found, giving a detection rate of 1.9%; 17 more cancers were also diagnosed outside the screening programme (contamination), seven in the screening group and 10 in the control group. Until February 2003, 85 participants had died (53 screened and 32 control) but none from prostate cancer.

CONCLUSIONS

Cancer detection rates can be increased with further early recalls; the clinical stage was localized in an important proportion of cancers detected.

Prostate specific antigen density. Is there a role for this parameter when screening for prostate cancer?

The objective of this paper is to validate prostate specific antigen (PSA) density (PSAD) routine use to enhance PSA specificity in men with normal digital rectal examination and intermediate PSA values. It is a retrospective study of 235 men from a prostate cancer (PCa) screening program. All of them presented PSA values between 4 and 10 ng/ml, normal digital rectal examination, and a transrectal ultrasound (TRUS) guided biopsy available (PSA>/=4 ng/ml as the sole criterion for biopsy). Multivariate analysis failed to demonstrate higher PSAD values in men with PCa. PSAD cutoff points higher than 0.07 ng/ml per cc were considered as unacceptable, with less than 95% sensitivity. When a cutoff point of 0.15 was considered, as many as 30.6% of the cancers were missed. In conclusion we cannot recommend the use of this parameter for the above mentioned purpose.Prostate Cancer and Prostatic Diseases (2001) 4, 146-149.

The clinical utility of the prostate specific membrane antigen reverse-transcription/polymerase chain reaction to detect circulating prostate cells: an analysis in healthy men and women

OBJECTIVE

To evaluate the overall specificity of nested reverse transcriptase-polymerase chain reaction (RT-PCR) to detect prostate-specific membrane antigen (PSM) mRNA in peripheral blood samples of healthy donors.

SUBJECTS AND METHODS

Peripheral blood samples were taken from 60 healthy blood-donors (30 men and 30 women aged < 50 years) and analysed for PSM-mRNA using nested RT-PCR (in 'hot-start' conditions and confirmed using nested EcoRI restriction enzyme). Intron-spanning primer pairs specific for human PSM were deduced from the GenBank sequence (M99487) using gene software. The outer primer pair for PSM was: fwd: 1368 5'-TCACCGGGACTCATGGGTGT-3'; reverse: 1860 5'-GCCTGAAGCAATTCCAAGTCGG-3'. Inner primer pair for PSM was: fwd: 1480 5'-AAGGAAGGGTGGAGACCTAG-3'; reverse: 5-ACTGAACTCTGGGGAAGGAC-3'. The integrity of cDNAs was checked using primer pairs specific for the housekeeping gene beta-actin. The specificity and false-positive rate were calculated assuming that the underlying prostate cancer incidence was nil.

RESULTS

The first PCR was negative for all samples (100% specificity; 0% false-positive rate). The nested PCR detected 23 positive samples (23/60, 38%) with an overall specificity of 62% (false positive rate, 38%).

CONCLUSION

Nested RT-PCR of PSM-mRNA in peripheral blood is highly unspecific. Its clinical utility in the management of prostate cancer must be low. Further development is needed of quantitative RT-PCR, primers that identify prostatic PSM or another prostate-specific marker gene to differentiate PSM mRNA from circulating prostate cells and from non-prostatic tissues.

Polyphenols in red wine inhibit the proliferation and induce apoptosis of LNCaP cells

OBJECTIVE

To assess the effect of five polyphenol constituents of red wine (quercetin, morin, rutin, gallic acid and tannic acid) on the proliferation of LNCaP cells, and to quantify the extent of apoptosis with each polyphenol.

MATERIALS AND METHODS

LNCaP cells (500) were cultured in microtitre plates and treated with gallic acid, tannic acid, quercetin (1, 5 and 10 micromol/L), rutin and morin (25, 50 and 75 micromol/L). A colorimetric immunoassay was then used to determine the extent of proliferation at 24, 48, 72 and 96 h, and a cell-death detection assay to assess apoptosis at 24, 48 and 72 h.

RESULTS

Gallic and tannic acid (5 and 10 micromol/L), morin (50 and 75 micromol/L), quercetin (5 and 10 micromol/L) and rutin (50 and 75 micromol/L) all significantly inhibited (P<0.05) cell proliferation compared with the control. Apoptotic indexes were significantly greater (P<0.01) in the presence of gallic (5 and 10 micromol/L) and tannic acid (5 and 10 micromol/L), and rutin (75 micromol/L, P<0.05) than in the control. The apoptotic effect of morin (75 micromol/L), although significant (P<0.01), only appeared at 72 h. Conversely, while significant (P<0.05) quercetin (5 and 10 micromol/L) had a transient (first 48 h) apoptotic effect compared with the control.

CONCLUSION

Quercetin, rutin, morin, gallic acid and tannic acid inhibited the growth of LNCaP cells at different concentrations, and induced apoptosis. The results provide a strong rationale for studying the in vivo effects of these compounds.

QT dispersion within the first 6 months after an acute myocardial infarction: relationship with systolic function, left ventricular volumes, infarct related artery status and clinical outcome

INTRODUCTION

We analysed QT dispersion within the first 6 months postinfarction, its relationship with the main established risk stratifiers and its clinical value.

METHODS AND RESULTS

In 55 patients with a first Q-wave myocardial infarction the 12-lead electrocardiogram was scanned and digitised for analysis of QT dispersion (QT maximum-QT minimum) at first day (72 [61-96] ms), first week (69 [47-90] ms), first month (67 [46-88] ms) and sixth month (47 [40-74] ms; P<0.0001 vs. first day). Cardiac catheterization was performed at first week and at sixth month; QT dispersion was not related to ejection fraction, left ventricular volumes, infarct related artery status or contractile reserve (improvement of the infarcted area with low-dose dobutamine); no relation was found between QT dispersion decrease from first week to sixth month with regional systolic function improvement. Finally, during a mean follow-up period of 35+/-22 months QT dispersion was not independently related to clinical events.

CONCLUSION

QT dispersion decreases progressively during the first months after myocardial infarction. These changes should be taken into account to define cut-off values of clinical interest in this phase. This variable does not seem related to the classic prognosis predictors. In a nonselected postinfarction population it has a low clinical value.

[Cholesterol crystals embolization. A case report]

Cholesterol Crystals Embolization is not a very frequent entity that happens in people with atheromatous disease of spontaneous for or after the realization of vascular manipulation (angiographic, angioplasty procedures, cardiovascular surgery) or more rarely with the treatment with oral anticoagulants and after thrombolytic therapy. The clinical presentation is according to the arterial affected territory and so from diagnosed cases in autopsy reports to florid clinic forms exist. The more frequent are the cutaneous manifestations with apparition of livedo reticularis and purple toes that could go accompanied of necrosis of lower limbs, consecutive from the renal manifestations and the gastrointestinal tract one. The diagnosis is based on the biopsy of organ affected lesions to level of arterioles, that revealed characteristic cholesterol clefts, above all the cutaneous biopsy, muscular and in any case renal. As for the treatment is symptomatic with analgesics, antiplatelet agents, anti-inflammatory, etc ... but it doesn't after the presage and the evolution of the illness. A clear contraindication exists to the use of oral anticoagulants and heparin.

ST-segment elevation on Q-leads during exercise in patients with ST-segment elevation at rest after myocardial infarction

INTRODUCTION

ST-segment elevation on Q-leads after an acute myocardial infarction is related to a greater infarct size. The meaning of a further exercise-induced ST-segment elevation in these patients has not been analyzed.

METHOD

Thirty-six patients with ST-segment elevation on Q-leads were studied after a first acute myocardial infarction. Exercise testing and cardiac catheterization were performed at the first week. Left ventricular volumes (ml/m(2)); the extent of abnormal wall motion (AWM: chords); contractile reserve (AWM improvement with low dose dobutamine) and coronary patency in the culprit artery were analyzed. Cardiac catheterization was repeated at the sixth month in 20 patients; systolic recovery (AWM improvement), left ventricular volumes and coronary patency were again evaluated.

RESULTS

Patients with exercise-induced ST-segment elevation in two or more Q-leads (n=21) showed lesser contractile reserve (6+/-6 vs. 12+/-7 chords, P=0.01) than patients without exercise-induced ST-segment elevation (n=13). AWM (F=8.1) and absence of exercise-induced ST-segment elevation (F=9.5; positive predictive value: 80%; negative predictive value: 68%) were the only independent predictors of contractile reserve. Nevertheless, this electrocardiographic sign was not related to left ventricular volumes, coronary patency or systolic function and it did not predicted late systolic recovery.

CONCLUSIONS

In patients with baseline ST-segment elevation on Q-leads an exercise-induced ST-segment elevation is independently related to a lesser contractile reserve but not to the evolution of volumes or regional dysfunction during the first 6 months post-infarction. Therefore, the clinical value of this sign seems to be limited to the non-invasive detection of myocardial viability during the early post-infarction phase.

Detecting circulating prostate cells in patients with clinically localized prostate cancer: clinical implications for molecular staging

OBJECTIVE

To evaluate the clinical utility of using the reverse transcriptase-polymerase chain reaction (RT-PCR) to detect prostate-specific antigen (PSA) mRNA in peripheral blood samples from patients with prostate cancer, as a predictor of extraprostatic disease, and to assess any correlations with known predictive markers of this condition.

PATIENTS AND METHODS

Immediately before radical prostatectomy, peripheral blood samples were taken from 25 men with clinically localized prostate cancer and analysed for PSA mRNA using RT-PCR (in 'hot-start' conditions and confirmed using ClaI restriction enzyme). The relationships between PSA mRNA positivity, pathological and clinical features were analysed; PSA mRNA positivity, PSA level and biopsy Gleason score were then compared as predictors of extraprostatic disease.

RESULTS

There was no relationship between PSA mRNA positivity and pathological stage (pT2 or pT3), and no association between PSA mRNA positivity and serum PSA level, PSA density, the findings on a digital rectal examination or transrectal ultrasonography, and perineural invasion in the prostatic biopsy. However, there was a significant correlation between the Gleason score of the preoperative biopsy and PSA mRNA positivity. The best predictors of extraprostatic disease were the biopsy Gleason score and the PSA level.

CONCLUSION

There was no significant advantage in using the RT-PCR assay of PSA mRNA before surgery to stage prostate cancer and to discriminate between organ-confined and extraprostatic neoplasms.

Reliability of the routine cytological diagnosis in bladder cancer

OBJECTIVES

To establish the reliability of three cytopathologists for cytological diagnosis of primary bladder tumors.

METHODS

Preoperative voided urine specimens of 71 patients with bladder cancer and 55 noncancer controls were retrospectively and blindly reviewed by 3 independent cytologists, and their results compared. The estimation of the interobserver agreement was calculated using the weighted kappa coefficient. A multivariate analysis was carried out to identify the factors associated with the disagreement between the three observers. The sensitivity and specificity for each of the participants was calculated in order to clearly identify the origin of the disagreement, in terms of the performance of the diagnostic test in the hands of each observer. A comparison of the overall diagnostic performance was made by plotting sensitivity versus 1-specificity.

RESULTS

The weighted kappa coefficient among the 3 observers was 0.46. The multivariate analysis did not identify any variable that could have caused such disagreement. Vast differences in sensitivity and specificity were detected between observer 1 (sens. 0.90, spec. 0.45) and observers 2 (sens. 0.67, spec. 0.72) and 3 (sens. 0.71, spec. 0.80), but the overall diagnostic performance (sensitivity vs. 1-specificity) was superimposable in the 3 cases (p = NS).

CONCLUSIONS

Simple, reproducible and agreed-on-diagnostic criteria should be established to yield reliable results in a group of cytologists. The consideration of individual diagnostic performances can give a false idea of homogeneity between observers. In this field, concordance analysis makes quality control reliable and should be a routine procedure of any pathology department.

[Determinants of contractile reserve in the infarction area. A quantitative study using dobutamine in contrast left ventriculography]

AIM

The aim of this study was to relate the contractile reserve in infarction segments to the dysfunction at rest and to the residual coronary stenosis.

METHODS

The study group consisted of 95 patients with a first myocardial infarction. Contrast left ventricular at baseline and after dobutamine infusion at 7.5 microg/kg/min and coronary angiograms were performed. The centerline method was used to quantify the extent of dysfunction (percentage of chords with dysfunction in the territory of the infarction artery) and its maximum severity (maximum units of standard deviation [SD] below the normal wall motion reference). Reduction of dysfunction extent with dobutamine was measured.

RESULTS

On increasing baseline dysfunction severity, both the magnitude of the response to dobutamine ( 2 SD 3 SD 4 SD +/- 5 SD [n = 15] = 9+/-13%, > 5 SD [n = 13] = 3+/-4%, p = 0,0001), and the number of patients with a significant (> or =15%) positive response ( 2 SD 3 SD 4 SD 5 SD = 0%, p<0,0001) decreased. There were no differences in dobutamine improvement among the subgroups with (n = 84) or without (n = 11) significant stenosis in the infarction artery (18+/-15 vs. 16 +/-18%), or between the subgroups with a patent (n = 76, 18+/-19%) or occluded (n = 19, 11+/-11%) artery.

CONCLUSIONS

Dobutamine response is related to dysfunction severity in the infarction area: when the severity is 5 (high negative response prevalence), dobutamine testing does not seem indicate. The existence of residual coronary stenosis does not attenuate contractile reserve at low dobutamine doses.

Wall motion of noninfarcted myocardium. Relationship to regional and global systolic function and to early and late left ventricular dilation

We studied the wall motion of the noninfarcted area and its role in left ventricular remodeling. The study group consisted of 43 patients with a first Q-wave acute myocardial infarction and single-vessel disease. Cardiac catheterization was performed at the first week, and was repeated six months later. Left ventricular volumes, wall motion at the infarcted and noninfarcted area, ejection fraction and infarction-related artery status were quantified. Hyperkinesia was only found at the first week in 22% of cases, and at the sixth month in 26% of cases. Wall motion at the noninfarcted area correlated with wall motion at the infarcted area (one week: r=0.53 p<0.0001; six months: r=0.52 p=0.01), ejection fraction (one week: r=0.69 p<0.0001; six months: r=0.56 p=0.006), end-diastolic volume (one week: r=-0.48 p=0.002; six months: r=-0.48 p=0.02) and end-systolic volume (one week: r=-0.70 p<0.0001; six months: r=-0.64 p=0.001). The improvement of the noninfarcted area (from the first week to the sixth month) was only related to basal (one week) wall motion in this area (r=-0.58 p=0.003). We conclude that after an intermediate-large infarction, most patients exhibit a normal or hypokinetic noninfarcted area. Patients with a more depressed infarcted area show poorer contractility at the noninfarcted area. area exhibit greater progressive improvement.

Prostate specific antigen variation in patients without clinically evident prostate cancer

PURPOSE

We address long-term within individual variation of serum prostate specific antigen (PSA) in men without clinical or biopsy evidence of prostate cancer.

MATERIALS AND METHODS

We studied 943 men from a prostate cancer screening program with 2 PSA (PSA1 and PSA2) measurements available. A third PSA (PSA3) was obtained from 571 men. Only participants with no clinical evidence of cancer were included in the study. Within individual PSA variability was calculated based on indexes of percent coefficient of variation, ratio difference and PSA velocity. The relationship among these indexes, interval between measurements and number of PSA samples was assessed.

RESULTS

Mean interval was 670.4 days between PSA1 and PSA2, and 801.8 days between PSA2 and PSA3 (p<0.001). Mean coefficient of variation was 18% after 2 and 15.7% after 3 PSA measurements. Mean ratio differences were -0.047 ng./ml. for 2 and 0.033 ng./ml. for 3 samples. Mean PSA velocity was -0.128 ng./ml. per year for 2 and -0.055 ng./ml. per year for 3 samples, with 95% confidence intervals of 0.634 and 0.315, respectively. Variability was higher if only 2 PSA measurements were done (p<0.001). No clear relationship was found between individual variability and interval between measurements.

CONCLUSIONS

PSA velocity is within normal limits in almost all men (more than 95%) without clinically relevant prostate cancer. PSA individual variability is not fully dependent on the time between measurements when intervals are long, and can be substantially decreased with a third PSA sample.

Low-dose dobutamine testing using contrast left ventriculography in the same session as coronary angiography predicts the improvement of left ventricular function after coronary angioplasty in postinfarction patients

The role of percutaneous transluminal coronary angioplasty (PTCA) in the subacute or chronic phases of myocardial infarction remains controversial. This study investigates the usefulness of dobutamine contrast left ventriculography in a single session with coronary angiography for predicting the improvement of ventricular function after PTCA. The study group consisted of 30 patients in whom a contrast left ventricular angiogram and PTCA were performed after a first myocardial infarction. The centerline method was used to calculate dysfunction extent at baseline and its variation during dobutamine infusion at 7.5 microg/kg/min; contractile reserve was defined as a significant (> or = 15%) reduction of dysfunction extent. A second ventricular angiogram was performed 6 months later in all patients. Abnormal wall motion extent decreased at 6 months after PTCA (84+/-21% vs 70+/-29%, p = 0.0001). Wall motion improvement after PTCA correlated with the response to dobutamine (r = 0.54, p = 0.002). Ten patients showed a significant reduction (> or = 15%) of dysfunction extent at 6 months; dobutamine testing had a 80% sensitivity, 84% specificity, 67% positive predictive value, and 89% negative predictive value in detecting regional function improvement. In the subgroup of 21 patients without restenosis, both the correlation between dysfunction improvement after PTCA and response to dobutamine (r = 0.72, p = 0.0001) and the accuracy of dobutamine testing (sensitivity 88%, specificity 92%, positive predictive value 88%, and negative predictive value 92%) increased. The ejection fraction significantly increased (>5%) after PTCA in 6 patients; dobutamine testing had a 67% sensitivity, 74% specificity, 44% positive predictive value, and 88% negative predictive value in predicting the increase in the ejection fraction. In the subgroup without restenosis the improvement of the ejection fraction correlated with the response to dobutamine (r = 0.63, p = 0.007), and the sensitivity of dobutamine testing was 80%, specificity 83%, positive predictive value 67%, and negative predictive value 91%. In conclusion, dobutamine contrast left ventriculography testing in the same session as coronary angiography predicts regional function and ejection fraction improvement after PTCA in postinfarction patients, particularly when restenosis does not develop.