Urinary EpCAM in urothelial bladder cancer patients: characterisation and evaluation of biomarker potential

Background:

Epithelial cell adhesion molecule is overexpressed in bladder tumours and released from bladder cancer cells in vitro. We test the hypotheses that urinary EpCAM could act as a biomarker for primary bladder cancer detection and risk stratification.

Methods:

Epithelial cell adhesion molecule was measured by ELISA in urine from 607 patients with primary bladder tumours and in urine from 53 non-cancer controls. Mann–Whitney tests and ROC analyses were used to determine statistical significance and discrimination between non-cancer controls and different stages and grades of disease. Multivariable modelling and Kaplan–Meier analyses were used to determine prognostic significance. The structure of urinary EpCAM was investigated by western blotting and mass spectrometry.

Results:

Urinary EpCAM levels increase with stage and grade of bladder cancer. Alongside grade and stage, elevated urinary EpCAM is an independent indicator of poor prognosis with a hazard ratio of 1.76 for bladder cancer-specific mortality. The soluble form of EpCAM in urine is the extracellular domain generated by cleavage between ala243 and gly244. Further studies are required to define the influence of other urinary tract malignancies and benign urological conditions on urinary EpCAM.

Conclusion:

The extracellular domain of EpCAM is shed into urine by bladder tumours. Urinary EpCAM is a strong indicator of bladder cancer-specific survival, and may be useful within a multi-marker panel for disease detection or as a stand-alone marker to prioritise the investigation and treatment of patients. The mechanisms and effects of EpCAM cleavage in bladder cancer are worthy of further investigation, and may identify novel therapeutic targets.     

EpCAM is overexpressed in local and metastatic prostate cancer,suppressed by chemotherapy and modulated by MET-associated miRNA-200c/205

Background:

Expression of epithelial cell adhesion molecule (EpCAM) is deregulated in epithelial malignancies. Beside its role in cell adhesion, EpCAM acts as signalling molecule with tumour-promoting functions. Thus, EpCAM is part of the molecular network of oncogenic receptors and considered an interesting therapeutic target.

Methods:

Here, we thoroughly characterised EpCAM expression on mRNA and protein level in comprehensive tissue studies including non-cancerous prostate specimens, primary tumours of different grades and stages, metastatic lesions, and therapy-treated tumour specimens, as well as in prostate cancer cell lines.

Results:

Epithelial cell adhesion molecule was overexpressed at mRNA and at protein level in prostate cancer tissues and cell lines. Altered EpCAM expression was an early event in prostate carcinogenesis with an upregulation in low-grade cancers and further induction in high-grade tumours and metastatic lesions. Interestingly, EpCAM was repressed upon induction of epithelial-to-mesenchymal transition (EMT) following chemotherapeutic treatment with docetaxel. Oppositely, re-induction of the epithelial phenotype through miRNAs miR-200c and miR-205, two inducers of mesenchymal-to-epithelial transition (MET), led to re-induction of EpCAM in chemoresistant cells. Furthermore, we prove that EpCAM cleavage, the first step of EpCAM signalling takes place in prostate cancer cells but in contrast to other cancer entities, EpCAM has no measurable impact on the proliferative behaviour of prostate cells, in vitro.

Conclusions:

In conclusion, our data confirm that EpCAM overexpression is an early event during prostate cancer progression. Epithelial cell adhesion molecule displays a dynamic, heterogeneous expression and associates with epithelial cells rather than mesenchymal, chemoresistant cells along with processes of EMT and MET.     

Clinical prognostic value of combined analysis of Aldh1, Survivin,and EpCAM expression in colorectal cancer

Background:

Tumour aggressiveness might be related to the degree of main cancer hallmark acquirement of tumour cells, reflected by expression levels of specific biomarkers. We investigated the expression of Aldh1, Survivin, and EpCAM, together reflecting main cancer hallmarks, in relation to clinical outcome of colorectal cancer (CRC) patients.

Methods:

Immunohistochemistry was performed using a tumour tissue microarray of TNM (Tumour, Node, Metastasis)-stage I–IV CRC tissues. Single-marker expression or their combination was assessed for associations with the clinical outcome of CRC patients (N=309).

Results:

Increased expression of Aldh1 or Survivin, or decreased expression of EpCAM was each associated with poor clinical outcome, and was therefore identified as clinically unfavourable expression. Analyses of the combination of all three markers showed worse clinical outcome, specifically in colon cancer patients, with an increasing number of markers showing unfavourable expression. Hazard ratios ranged up to 8.3 for overall survival (P<0.001), 36.6 for disease-specific survival (P<0.001), and 27.1 for distant recurrence-free survival (P<0.001).

Conclusions:

Our data identified combined expression levels of Aldh1, Survivin, and EpCAM as strong independent prognostic factors, with high hazard ratios, for survival and tumour recurrence in colon cancer patients, and therefore reflect tumour aggressiveness.     

Endogenous BTG2 expression stimulates migration of bladder cancer cells and correlates with poor clinical prognosis for bladder cancer patients

Background:

The B-cell translocation gene 2 (BTG2) is considered to act as a tumour-suppressor gene because of its antiproliferative and antimigratory activities. Higher levels of BTG2 expression in tumour cells have been linked to a better clinical outcome for several cancer entities. Here, we investigated the expression and function of BTG2 in bladder cancer.

Methods:

The expression of BTG2 in bladder cancer cells was silenced by RNA interference. Cell motility was investigated by wound healing and Boyden chamber assays. The protein expression of BTG2 in bladder cancer was studied by immunohistochemistry.

Results:

We observed that targeted suppression of BTG2 by RNA interference did not result in growth stimulation but led to a substantial inhibition of bladder cancer cell motility. Tissue microarray analyses of bladder cancer cystectomy specimens revealed that higher BTG2 expression levels within the tumours correlated strongly with a decreased cancer-specific survival for bladder cancer patients.

Conclusion:

These results indicate that endogenous BTG2 expression contributes to the migratory potential of bladder cancer cells. Moreover, high levels of BTG2 in bladder cancers are linked to decreased cancer-specific survival. These findings question the conception that BTG2 generally acts as a tumour suppressor and typically represents a favourable clinical marker for cancer patients.     

Serum lactate dehydrogenase and survival following cancer diagnosis

Background:

There is evidence that high level of serum lactate dehydrogenase (LDH) is associated with poorer overall survival in several malignancies, but its link to cancer-specific survival is unclear.

Methods:

A total of 7895 individuals diagnosed with cancer between 1986 and 1999 were selected for this study. Multivariable Cox proportional hazards regression was used to assess overall and cancer-specific death by the z-score and clinical categories of serum LDH prospectively collected within 3 years before diagnosis. Site-specific analysis was performed for major cancers. Analysis was repeated by different lag times between LDH measurements and diagnosis.

Results:

At the end of follow-up, 5799 participants were deceased. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cancer-specific death in the multivariable model were 1.43 (1.31–1.56) and 1.46 (1.32–1.61), respectively, for high compared with low prediagnostic LDH. Site-specific analysis showed high LDH to correlate with an increased risk of death from prostate, pulmonary, colorectal, gastro-oesophageal, gynaecological and haematological cancers. Serum LDH assessed within intervals closer to diagnosis was more strongly associated with overall and cancer-specific death.

Conclusions:

Our findings demonstrated an inverse association of baseline serum LDH with cancer-specific survival, corroborating its role in cancer progression.     

Telomere length is a novel predictive biomarker of sensitivity to anti-EGFR therapy in metastatic colorectal cancer

Background:

Telomeres are TTAGGG tandem repeats capping chromosomal ends and partially controlled by the telomerase enzyme. The EGFR pathway putatively regulates telomerase function, prompting an investigation of telomere length (TL) and its association with anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer (mCRC).

Methods:

Colorectal cancer cell lines were treated with multiple drugs and sensitivity determined. Clinical information was gathered from 75 patients who had received anti-EGFR drugs. Telomere length was measured using a validated qRT–PCR technique.

Results:

In CRC cell lines, TL independently predicted cetuximab sensitivity. Cells with shorter TL had growth inhibition of 18.6±3.41% as compared with 41.39±8.58% in longer TL (P=0.02). These in vitro findings were validated clinically, in a robust multivariate model. Among patients with KRas WT tumours, those with longer TL had a superior median progression-free survival (PFS) of 24.9 weeks than those with shorter TL; median 11.1 weeks, HR 0.31; P=0.048.

Conclusion:

Telomere length could be a potential unique biomarker predictive of clinical benefit (PFS) of mCRC patients treated with anti-EGFR therapy. This is the novel demonstration of a complex hitherto undescribed interaction, placing anti-EGFR therapy, EGFR pathway, and the telomerase complex within a clinical context.     

Carcinoembryonic antigen is the preferred biomarker for in vivo colorectal cancer targeting

Background:

Colorectal cancer-specific biomarkers have been used as molecular targets for fluorescent intra-operative imaging, targeted PET/MRI, and selective cytotoxic drug delivery yet the selection of biomarkers used is rarely evidence-based. We evaluated sensitivities and specificites of four of the most commonly used markers: carcinoembryonic antigen (CEA), tumour-associated glycoprotein-72 (TAG-72), folate receptor-α (FRα) and Epithelial growth factor receptor (EGFR).

Methods:

Marker expression was evaluated semi-quantitatively in matched mucosal and colorectal cancer tissues from 280 patients using immunohistochemistry (scores of 0–15). Matched positive and negative lymph nodes from 18 patients were also examined.

Results:

Markers were more highly expressed in tumour tissue than in matched normal tissue in 98.8%, 79.0%, 37.1% and 32.8% of cases for CEA, TAG-72, FRα and EGFR, respectively. Carcinoembryonic antigen showed the greatest differential expression, with tumours scoring a mean of 10.8 points higher than normal tissues (95% CI 10.31–11.21, P<0.001). Similarly, CEA showed the greatest differential expression between positive and negative lymph nodes. Receiver operating characteristic analyses showed CEA to have the best sensitivity (93.7%) and specificity (96.1%) for colorectal cancer detection.

Conclusion:

Carcinoembryonic antigen has the greatest potential to allow highly specific tumour imaging and drug delivery; future translational research should aim to exploit this.     

Prognostic role of EGFR gene copy number and KRAS mutation in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy

Background:

Epidermal growth factor receptor (EGFR), evaluated by immunohistochemistry, has been shown to have prognostic significance in patients with colorectal cancer. Gene copy number (GCN) of EGFR and KRAS status predict response and outcome in patients treated with anti-EGFR therapy, but their prognostic significance in colorectal cancer patients is still unclear.

Methods:

We have retrospectively reviewed the baseline EGFR GCN, KRAS status and clinical outcome of 146 locally advanced rectal cancer (LARC) patients treated with preoperative chemoradiotherapy. Pathological response evaluated by Dworak''s tumour regression grade (TRG), disease-free survival (DFS) and overall survival (OS) were analysed.

Results:

Tumour regression grade 4 and TRG3–4 were achieved in 14.4 and 30.8% of the patients respectively. Twenty-nine (19.9%) and 33 patients (19.2%) had an EGFR/nuclei ratio >2.9 and CEP7 polisomy >50% respectively; 28 patients (19.2%) had a KRAS mutation. Neither EGFR GCN nor KRAS status was statistically correlated to TRG. 5-year DFS and OS were 63.3 and 71.5%, respectively, and no significant relation with EGFR GCN or KRAS status was found.

Conclusion:

Our data show that EGFR GCN and KRAS status are not prognostic factors in LARC treated with preoperative chemoradiation.     

Lifestyle factors associated with survival after colorectal cancer diagnosis

Background:

Aside from tumour stage and treatment, little is known about potential factors that may influence survival in colorectal cancer patients. The aim of this study was to investigate the associations between physical activity, obesity and smoking and disease-specific and overall mortality after a colorectal cancer diagnosis.

Methods:

A cohort of 879 colorectal cancer patients, diagnosed in Western Australia between 2005 and 2007, were followed up to 30 June 2012. Cox''s regression models were used to estimate the hazard ratios (HR) for colorectal cancer-specific and overall mortality associated with self-reported pre-diagnosis physical activity, body mass index (BMI) and smoking.

Results:

Significantly lower overall and colorectal cancer-specific mortality was seen in females who reported any level of recent physical activity than in females reporting no activity. The colorectal cancer-specific mortality HR for increasing levels of physical activity in females were 0.34 (95% CI=0.15, 0.75), 0.37 (95% CI=0.17, 0.81) and 0.41 (95% CI=0.18, 0.90). Overweight and obese women had almost twice the risk of dying from any cause or colorectal cancer compared with women of normal weight. Females who were current smokers had worse overall and colorectal cancer-specific mortality than never smokers (overall HR=2.64, 95% CI=1.18, 5.93; colorectal cancer-specific HR=2.70, 95% CI=1.16, 6.29). No significant associations were found in males.

Conclusion:

Physical activity, BMI and smoking may influence survival after a diagnosis of colorectal cancer, with more pronounced results found for females than for males.     

The impact of patient comorbidity on cancer stage at diagnosis

Background:

It is known that cancer stage is affected by comorbidity, but the evidence regarding the magnitude and even direction of this effect is highly inconsistent and poorly understood. The aims of this study were to establish the impact of comorbidity on cancer stage at diagnosis, using both specific individual comorbid conditions and a global measure of comorbidity; and to assess whether this impact varied by cancer site, level of comorbidity burden and individual comorbidity type.

Methods:

We examined comorbidity among 14 096 patients with breast, colon, rectal, liver, stomach, ovarian, uterine, bladder or kidney cancer. Patients were identified from cancer registry data, and then linked to hospitalisation data to determine the presence of comorbidity in the 5 years preceding cancer diagnosis. Individual comorbid conditions were identified using ICD-10 codes, and overall burden of comorbidity attributed using a cancer-specific measure of comorbidity (C3 Index).

Results:

We observed that the presence of patient comorbidity (a) increases the odds of being diagnosed with distant metastases, (b) does not lead to earlier diagnosis and (c) increases the likelihood of a patient receiving no stage of disease at diagnosis.

Conclusions:

Patient comorbidity has a substantial impact on cancer stage at diagnosis; however, this impact varies considerably by cancer type, individual comorbid condition and overall comorbidity burden.     

Diabetes and prognosis in older persons with colorectal cancer

Background:

Epidemiological studies have reported that diabetes significantly increases overall mortality in patients with colorectal cancer. However, it is unclear whether diabetes increases colorectal cancer-specific mortality. We used the US Surveillance Epidemiology and End Results (SEER) database linked with Medicare claims data to assess the influence of pre-existing diabetes on prognosis of patients with colorectal cancer.

Methods:

Data from 61 213 patients aged 67 or older with colorectal cancer diagnosed between 2003 and 2009 were extracted and prospectively followed through the date of death or the end of 2012 if the patient was still alive. Diabetes cases with and without complications were identified based on an algorithm developed for the Chronic Condition Data Warehouse (CCW). Cox models were used to estimate hazard ratios (HRs) for total mortality. The proportional subdistribution hazards model proposed by Fine and Gray was used to estimate HRs for colorectal cancer-specific mortality.

Results:

Compared with patients without diabetes, colorectal cancer patients with pre-existing diabetes had significantly higher risk of overall mortality (HR=1.20, 95 % confidence interval (95% CI): 1.17–1.23). The HR for overall mortality was more pronounced for patients who had diabetes with complications (HR=1.50, 95% CI: 1.42–1.58). However, diabetes was not associated with increased colorectal cancer-specific mortality after accounting for non-colorectal cancer outcomes as competing risk.

Conclusions:

Pre-existing diabetes increased risk of total mortality among patients with colorectal cancer, especially among cancer patients who had diabetes with complications. The increased risk of total mortality associated with diabetes was primarily explained by increased cardiovascular-specific mortality, not by increased colorectal cancer-specific mortality.     

Diagnosis of bladder cancer by immunocytochemical detection of minichromosome maintenance protein-2 in cells retrieved from urine

Background:

We tested the accuracy of immunocytochemistry (ICC) for minichromosome maintenance protein-2 (MCM-2) in diagnosing bladder cancer, using cells retrieved from urine.

Methods:

Adequate samples were obtained from 497 patients, the majority presenting with gross haematuria (GH) or undergoing cystoscopic surveillance (CS) following previous bladder cancer. We performed an initial study of 313 patients, followed by a validation study of 184 patients. In all cases, presence/absence of bladder cancer was established by cystoscopy/biopsy.

Results:

In the initial study, receiver operator characteristic analysis showed an area under the curve of 0.820 (P<0.0005) for the GH group and 0.821 (P<0.01) for the CS group. Optimal sensitivity/specificity were provided by threshold values of 50+ MCM-2-positive cells in GH samples and 200+ cells in CS samples, based on a minimum total cell number of 5000. Applying these thresholds to the validation data set gave 81.3% sensitivity, 76.0% specificity and 92.7% negative predictive value (NPV) in GH and 63.2% sensitivity, 89.9% specificity and 89.9% NPV in CS. Minichromosome maintenance protein-2 ICC provided clinically relevant improvements over urine cytology, with greater sensitivity in GH and greater specificity in CS (P=0.05).

Conclusions:

Minichromosome maintenance protein-2 ICC is a reproducible and accurate test that is suitable for both GH and CS patient groups.     

The miR-143/-145 cluster regulates plasminogen activator inhibitor-1 in bladder cancer

Background:

Upregulation of the proto-oncogene plasminogen activator inhibitor-1 (PAI-1) is a common hallmark of various solid tumours, but the mechanisms controlling its expression are not fully understood.

Methods:

We investigate microRNAs (miRNAs) regulating PAI-1 in a panel of normal bladder urothelial biopsies, superficial Ta bladder tumours and invasive T1–T4 tumours using expression microarrays and qRT–PCR. The prognostic implications of PAI-1 deregulation are established by tissue microarray staining of non-muscle-invasive bladder tumours. MicroRNA repression of PAI-1 is assayed by ectopic miRNA expression, argonaute immunoprecipitation and luciferase assays.

Results:

We found that the miR-143/-145 cluster is downregulated in all stages of bladder cancer and inversely correlated with PAI-1 expression. Mature miR-143 and miR-145 are coordinately expressed, and both directly target the PAI-1 3′UTR, leading to reduced PAI-1 mRNA and protein levels. Furthermore, we show that PAI-1 and miR-145 levels may serve as useful prognostic markers for non-muscle-invasive bladder tumours for which accurate progressive outcome is currently difficult to predict.

Conclusion:

This report provides the first evidence for direct miRNA regulation of PAI-1 in bladder cancer. We also demonstrate mRNA co-targeting by a cluster of non-family miRNAs, and suggest miR-145 and PAI-1 as clinically relevant biomarkers in bladder cancer.     

MicroRNA-126 inhibits invasion in bladder cancer via regulation of ADAM9

Background:

The miRNA deregulation is commonly observed in human malignancies, where they act as tumour suppressors or oncogenes. Despite the association of several miRNAs with bladder cancer, little is known about the miRNAs that contribute to bladder cancer progression from non-muscle invasive (NMI) to muscle-invasive (MI) disease.

Methods:

We first profiled the expression of miRNAs and mRNAs in a cohort of urothelial carcinomas and further characterised the role of miR-126 in invasion, as it emerged as the most downregulated miRNA between MI and NMI tumours.

Results:

We found that restoration of miR-126 levels attenuated the invasive potential of bladder cancer cells. Mechanistically, we identified the role of miR-126 in invasion through its ability to target ADAM9. Notably, a significant inverse correlation between miR-126 and ADAM9 expression was observed, where ADAM9 was upregulated in MI bladder cancer cells. While knockdown of ADAM9 attenuated the invasiveness of cells with low miR-126 levels, experimental upregulation of ADAM9 recapitulated the invasive phenotype. Furthermore, ADAM9 expression assessed by immunohistochemistry significantly correlated with poor prognosis in patients with urothelial carcinoma.

Conclusions:

In this study we describe the role of miR-126 in bladder cancer progression, identifying miR-126 and ADAM9 as potential clinical biomarkers of disease aggressiveness.